@article{NGOIPALA2024829,

title = {Computational unravelling of cathodic hydride formation on palladium surfaces},

author = {Apinya Ngoipala and Raju Lipin and Ryan Lacdao Arevalo and Matthias Vandichel},

url = {https://www.sciencedirect.com/science/article/pii/S0360319923062456},

doi = {https://doi.org/10.1016/j.ijhydene.2023.12.019},

issn = {0360-3199},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {International Journal of Hydrogen Energy},

volume = {53},

pages = {829-839},

abstract = {Palladium (Pd) is well-known for its role in catalyzing hydrogen-based reduction reactions, owing to its excellent catalytic activity and hydrogen storage ability. Its surface and subsurface structures under electrochemical conditions are vital in understanding the hydrogen evolution reaction (HER) mechanism at the Pd cathodes where the most active sites are located on ‘in situ’ formed Pd-hydride layers. In this work, we investigate the process of Pd-hydride formation as well as the step-by-step formation and stability of Pd-hydride/Pd interfaces under electrochemical conditions using first-principles calculations. Our results reveal that among the low-indexed surfaces (111), (110) and (100), the (111) surface is expected to be the most dominant surface in a Pd nanostructure in addition to being the most preferred surface for hydrogen adsorption. Based on calculated Pourbaix diagrams, we can identify the relevant regions close to the equilibrium electrode potential and pH for proton electroreduction and hydrogen evolution, where the Pd surfaces start to be covered by hydrogen adatoms, and when the electrode potential is decreased, there are clear thermodynamic indications for more and more subsurface hydride layers. Overall, the results provide insights into the stability and formation of hydrogen-containing Pd surfaces, forming PdH/Pd type interfaces. Our idealized model systems are a first step towards elucidation of relevant active sites on Pd.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/jacs.3c07198,

title = {Highly Selective p-Xylene Separation from Mixtures of C8 Aromatics by a Nonporous Molecular Apohost},

author = {Maryam Rahmani and Catiúcia R. M. O. Matos and Shi-Qiang Wang and Andrey A. Bezrukov and Alan C. Eaby and Debobroto Sensharma and Yassin Hjiej-Andaloussi and Matthias Vandichel and Michael J. Zaworotko},

url = {https://doi.org/10.1021/jacs.3c07198},

doi = {10.1021/jacs.3c07198},

year  = {2023},

date = {2023-12-06},

urldate = {2023-01-01},

journal = {Journal of the American Chemical Society},

volume = {145},

number = {50},

pages = {27316-27324},

note = {PMID: 38055597},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acsabm.3c00452,

title = {Anticancer Potential of Dendritic Poly(aryl ether)-Substituted Polypyridyl Ligand-Based Ruthenium(II) Coordination Entities},

author = {Liju Raju and Sousa Javan Nikkhah and MosaChristas K and Matthias Vandichel and Rajkumar Eswaran},

url = {https://doi.org/10.1021/acsabm.3c00452},

doi = {10.1021/acsabm.3c00452},

year  = {2023},

date = {2023-10-20},

urldate = {2023-01-01},

journal = {ACS Applied Bio Materials},

volume = {6},

number = {10},

pages = {4226-4239},

note = {PMID: 37782900},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/anie.202309985,

title = {Shape-Memory Effect Enabled by Ligand Substitution and CO2 Affinity in a Flexible SIFSIX Coordination Network},

author = {Bai-Qiao Song and Mohana Shivanna and Mei-Yan Gao and Shi-Qiang Wang and Cheng-Hua Deng and Qing-Yuan Yang and Sousa Javan Nikkhah and Matthias Vandichel and Susumu Kitagawa and Michael J. Zaworotko},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202309985},

doi = {https://doi.org/10.1002/anie.202309985},

year  = {2023},

date = {2023-09-28},

urldate = {2023-01-01},

journal = {Angewandte Chemie International Edition},

volume = {62},

number = {47},

pages = {e202309985},

abstract = {Abstract We report that linker ligand substitution involving just one atom induces a shape-memory effect in a flexible coordination network. Specifically, whereas SIFSIX-23-Cu, [Cu(SiF6)(L)2]n, (L=1,4-bis(1-imidazolyl)benzene, SiF62−=SIFSIX) has been previously reported to exhibit reversible switching between closed and open phases, the activated phase of SIFSIX-23-CuN, [Cu(SiF6)(LN)2]n (LN=2,5-bis(1-imidazolyl)pyridine), transformed to a kinetically stable porous phase with strong affinity for CO2. As-synthesized SIFSIX-23-CuN, α, transformed to less open, γ, and closed, β, phases during activation. β did not adsorb N2 (77 K), rather it reverted to α induced by CO2 at 195, 273 and 298 K. CO2 desorption resulted in α′, a shape-memory phase which subsequently exhibited type-I isotherms for N2 (77 K) and CO2 as well as strong performance for separation of CO2/N2 (15/85) at 298 K and 1 bar driven by strong binding (Qst=45–51 kJ/mol) and excellent CO2/N2 selectivity (up to 700). Interestingly, α′ reverted to β after re-solvation/desolvation. Molecular simulations and density functional theory (DFT) calculations provide insight into the properties of SIFSIX-23-CuN.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.inorgchem.3c01777,

title = {Hf-Based MOF for Rapid and Selective Sensing of a Nerve Agent Simulant and an Aminophenol: Insights from Experiments and Theory},

author = {Subhrajyoti Ghosh and Raju Lipin and Apinya Ngoipala and Niklas Ruser and Diletta Morelli Venturi and Abhijeet Rana and Matthias Vandichel and Shyam Biswas},

url = {https://doi.org/10.1021/acs.inorgchem.3c01777},

doi = {10.1021/acs.inorgchem.3c01777},

year  = {2023},

date = {2023-08-28},

urldate = {2023-01-01},

journal = {Inorganic Chemistry},

volume = {62},

number = {36},

pages = {14632-14646},

note = {PMID: 37640009},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{zand_role_2023,

title = {Role of decomposition products in the oxidation of cyclohexene using a manganese(III) complex},

author = {Zahra Zand and Younes Mousazade and Ryan Lacdao Arevalo and Robabeh Bagheri and Mohammad Reza Mohammadi and Rahman Bikas and Petko Chernev and Pavlo Aleshkevych and Matthias Vandichel and Zhenlun Song and Holger Dau and Mohammad Mahdi Najafpour},

url = {https://doi.org/10.1038/s42004-023-00881-x},

doi = {10.1038/s42004-023-00881-x},

issn = {2399-3669},

year  = {2023},

date = {2023-05-01},

journal = {Communications Chemistry},

volume = {6},

number = {1},

pages = {94},

abstract = {Metal complexes are extensively explored as catalysts for oxidation reactions; molecular-based mechanisms are usually proposed for such reactions. However, the roles of the decomposition products of these materials in the catalytic process have yet to be considered for these reactions. Herein, the cyclohexene oxidation in the presence of manganese(III) 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine chloride tetrakis(methochloride) (1) in a heterogeneous system via loading the complex on an SBA-15 substrate is performed as a study case. A molecular-based mechanism is usually suggested for such a metal complex. Herein, 1 was selected and investigated under the oxidation reaction by iodosylbenzene or (diacetoxyiodo)benzene (PhI(OAc)2). In addition to 1, at least one of the decomposition products of 1 formed during the oxidation reaction could be considered a candidate to catalyze the reaction. First-principles calculations show that Mn dissolution is energetically feasible in the presence of iodosylbenzene and trace amounts of water.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/smll.202206945,

title = {A Robust Molecular Porous Material for C2H2/CO2 Separation},

author = {Mei-Yan Gao and Debobroto Sensharma and Andrey A. Bezrukov and Yassin H. Andaloussi and Shaza Darwish and Chenghua Deng and Matthias Vandichel and Jian Zhang and Michael J. Zaworotko},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.202206945},

doi = {https://doi.org/10.1002/smll.202206945},

year  = {2023},

date = {2023-01-01},

urldate = {2022-12-22},

journal = {Small},

volume = {19},

number = {n/a},

issue = {11},

pages = {2206945},

abstract = {Abstract A molecular porous material, MPM-2, comprised of cationic [Ni2(AlF6)(pzH)8(H2O)2] and anionic [Ni2Al2F11(pzH)8(H2O)2] complexes that generate a charge-assisted hydrogen-bonded network with pcu topology is reported. The packing in MPM-2 is sustained by multiple interionic hydrogen bonding interactions that afford ultramicroporous channels between dense layers of anionic units. MPM-2 is found to exhibit excellent stability in water (>1 year). Unlike most hydrogen-bonded organic frameworks which typically show poor stability in organic solvents, MPM-2 exhibited excellent stability with respect to various organic solvents for at least two days. MPM-2 is found to be permanently porous with gas sorption isotherms at 298 K revealing a strong affinity for C2H2 over CO2 thanks to a high (ΔQst)AC [Qst (C2H2) − Qst (CO2)] of 13.7 kJ mol−1 at low coverage. Dynamic column breakthrough experiments on MPM-2 demonstrated the separation of C2H2 from a 1:1 C2H2/CO2 mixture at 298 K with effluent CO2 purity of 99.995% and C2H2 purity of >95% after temperature-programmed desorption. C-H···F interactions between C2H2 molecules and F atoms of AlF63− are found to enable high selectivity toward C2H2, as determined by density functional theory simulations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{D3NJ00335C,

title = {Peripherally “tertiary butyl ester” functionalized bipyridine cored dendrons: from synthesis and characterization to molecular dynamic simulation study},

author = {Liju Raju and Sousa Javan Nikkhah and Matthias Vandichel and Eswaran Rajkumar},

url = {http://dx.doi.org/10.1039/D3NJ00335C},

doi = {10.1039/D3NJ00335C},

year  = {2023},

date = {2023-01-01},

journal = {New J. Chem.},

volume = {47},

issue = {18},

pages = {8913-8924},

publisher = {The Royal Society of Chemistry},

abstract = {In this research, we have designed and synthesized a series of novel bipyridine cored poly(benzyl-ether) dendrons containing tertiary butyl esters at their periphery. The molecular structures of the synthesized dendrons were characterized via NMR and mass spectrometry. We investigated the solvent dependent hydrodynamic size of the synthesized dendrons in dimethyl sulfoxide (DMSO) and water using dynamic light scattering (DLS) experiments and the water contact angle of the dendrons was also analyzed. To understand the structure and solvation behaviour of these novel dendrons at the atomistic level, we performed all-atom molecular dynamics (MD) simulations. The behaviour, configuration, and size of the dendrons in DMSO and water were studied through calculation of the radius of gyration (Rg), radial distribution function g(r), and solvent accessible surface area (SASA). The modelling results confirmed the experimental observations that DMSO is a better solvent than water for dendrons as it results in a more unfolded molecular structure. Based on the above experimental results, these dendritic polymers are an excellent candidate for multifunctional theranostics platforms.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/jacs.3c01113,

title = {One Atom Can Make All the Difference: Gas-Induced Phase Transformations in Bisimidazole-Linked Diamondoid Coordination Networks},

author = {Kyriaki Koupepidou and Varvara I. Nikolayenko and Debobroto Sensharma and Andrey A. Bezrukov and Matthias Vandichel and Sousa Javan Nikkhah and Dominic C. Castell and Kolade A. Oyekan and Naveen Kumar and Aizhamal Subanbekova and William G. Vandenberghe and Kui Tan and Leonard J. Barbour and Michael J. Zaworotko},

url = {https://doi.org/10.1021/jacs.3c01113},

doi = {10.1021/jacs.3c01113},

year  = {2023},

date = {2023-01-01},

journal = {Journal of the American Chemical Society},

volume = {145},

number = {18},

pages = {10197-10207},

note = {PMID: 37099724},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/jacs.3c03505,

title = {Highly Productive C3H4/C3H6 Trace Separation by a Packing Polymorph of a Layered Hybrid Ultramicroporous Material},

author = {Mei-Yan Gao and Andrey A. Bezrukov and Bai-Qiao Song and Meng He and Sousa Javan Nikkhah and Shi-Qiang Wang and Naveen Kumar and Shaza Darwish and Debobroto Sensharma and Chenghua Deng and Jiangnan Li and Lunjie Liu and Rajamani Krishna and Matthias Vandichel and Sihai Yang and Michael J. Zaworotko},

url = {https://doi.org/10.1021/jacs.3c03505},

doi = {10.1021/jacs.3c03505},

year  = {2023},

date = {2023-01-01},

journal = {Journal of the American Chemical Society},

volume = {145},

number = {21},

pages = {11837-11845},

note = {PMID: 37204941},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acsami.2c02520,

title = {Enhanced Photocatalytic Hydrogen Evolution from Water Splitting on Ta2O5/SrZrO3 Heterostructures Decorated with CuxO/RuO2 Cocatalysts},

author = {Ali Margot Huerta-Flores and Francisco Ruiz-Zepeda and Cavit Eyovge and Jedrzej P. Winczewski and Matthias Vandichel and Miran Gaberšček and Nicolas D. Boscher and Han J. G. E. Gardeniers and Leticia M. Torres-Martínez and Arturo Susarrey-Arce},

url = {https://doi.org/10.1021/acsami.2c02520},

doi = {10.1021/acsami.2c02520},

year  = {2022},

date = {2022-07-12},

urldate = {2022-07-12},

journal = {ACS Applied Materials & Interfaces},

volume = {14},

issue = {28},

pages = {31767–31781},

note = {PMID: 35786845},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/smll.202202410,

title = {Elucidation of Structure–Activity Relations in Proton Electroreduction at Pd Surfaces: Theoretical and Experimental Study},

author = {Thorsten O. Schmidt and Apinya Ngoipala and Ryan L. Arevalo and Sebastian A. Watzele and Raju Lipin and Regina M. Kluge and Shujin Hou and Richard W. Haid and Anatoliy Senyshyn and Elena L. Gubanova and Aliaksandr S. Bandarenka and Matthias Vandichel},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.202202410},

doi = {https://doi.org/10.1002/smll.202202410},

year  = {2022},

date = {2022-06-20},

urldate = {2022-06-20},

journal = {Small},

volume = {n/a},

number = {18},

pages = {2202410},

abstract = {Abstract The structure–activity relationship is a cornerstone topic in catalysis, which lays the foundation for the design and functionalization of catalytic materials. Of particular interest is the catalysis of the hydrogen evolution reaction (HER) by palladium (Pd), which is envisioned to play a major role in realizing a hydrogen-based economy. Interestingly, experimentalists observed excess heat generation in such systems, which became known as the debated “cold fusion” phenomenon. Despite the considerable attention on this report, more fundamental knowledge, such as the impact of the formation of bulk Pd hydrides on the nature of active sites and the HER activity, remains largely unexplored. In this work, classical electrochemical experiments performed on model Pd(hkl) surfaces, “noise” electrochemical scanning tunneling microscopy (n-EC-STM), and density functional theory are combined to elucidate the nature of active sites for the HER. Results reveal an activity trend following Pd(111) > Pd(110) > Pd(100) and that the formation of subsurface hydride layers causes morphological changes and strain, which affect the HER activity and the nature of active sites. These findings provide significant insights into the role of subsurface hydride formation on the structure–activity relations toward the design of efficient Pd-based nanocatalysts for the HER.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RODRIGUEZOLGUIN2022101528,

title = {Chlorine in NiO promotes electroreduction of CO2 to formate},

author = {M. A. Rodriguez-Olguin and C. Flox and R. Ponce-Pérez and R. Lipin and F. Ruiz-Zepeda and J. P. Winczewski and T. Kallio and M. Vandichel and J. Guerrero-Sánchez and J. G. E. Gardeniers and N. Takeuchi and A. Susarrey-Arce},

url = {https://www.sciencedirect.com/science/article/pii/S2352940722001639},

doi = {https://doi.org/10.1016/j.apmt.2022.101528},

issn = {2352-9407},

year  = {2022},

date = {2022-05-23},

urldate = {2022-05-23},

journal = {Applied Materials Today},

volume = {28},

pages = {101528},

abstract = {We report the exceptional finding that NiO, a known electroactive catalyst for the reduction of CO2 to CO, can be tuned to become an active electrocatalyst for CO2 reduction to formate when chlorine is synthetically incorporated into NiO. The CO2 reduction reaction (CO2RR) is carried out on chlorine-containing NiO octahedral particles made by a solid-state synthesis method yielding a Faradaic efficiency (FE) of 70 % for formate production at -0.8 V vs. RHE with a partial current density of 14.7 mA/cm2. XPS confirms the presence of Ni3+ and Ni2+ species, indicating the existence of uncoordinated Ni. The Ni3+/Ni2+ ratio increases with the Cl concentrations on NiO. Cl concentrations are also confirmed with STEM-EDX. DFT modeling provides insights into the thermodynamic stability and CO2RR mechanism over the Cl-containing NiO surface. It is suggested that Cl can occupy the defective sites created by oxygen vacancies on the NiO model with Cl (O-alpha+Cl). The surface Pourbaix diagrams constructed from DFT indicate the preferred surface terminations favorable at the operating conditions for the CO2RR, which closely agrees with the experimental findings. The O-alpha+Cl has been found to promote CO2RR to formate. Our results create new possibilities in the development of earth-abundant electrocatalysts for selective CO2RR},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ALI2022121541,

title = {Hydrogen Evolution in Alkaline Medium on Intratube and Surface Decorated PtRu Catalyst},

author = {Farhan S. M. Ali and Ryan Lacdao Arevalo and Matthias Vandichel and Florian Speck and Eeva-Leena Rautama and Hua Jiang and Olli Sorsa and Kimmo Mustonen and Serhiy Cherevko and Tanja Kallio},

url = {https://www.sciencedirect.com/science/article/pii/S0926337322004829},

doi = {https://doi.org/10.1016/j.apcatb.2022.121541},

issn = {0926-3373},

year  = {2022},

date = {2022-05-23},

urldate = {2022-05-23},

journal = {Applied Catalysis B: Environmental},

volume = {315},

pages = {121541},

abstract = {For anion exchange membrane (AEM) electrolysis, challenges include finding an optimal catalyst for hydrogen evolution reaction (HER), as the noble metals are scarce while non-noble metals are inferior. Here, the noble metal amount is reduced in a straightforward solution synthesis which produces Pt-Ru surface nanoparticles and unique intratube nanowires decorated on single walled carbon nanotubes (SWNT). In half-cell tests, 5 wtPtRu-% Pt-Ru SWNT demonstrates stable 10mAcm−2 HER current at 46mV overpotential and outperforms commercial electrocatalysts. When integrated in an AEM electrolyser, a high current density of 500mAcm−2 at a low voltage of 1.72V is achieved with 34µgcm−2 metal loading. First-principles calculations reveal that both the Pt-Ru alloy nanoparticle and intratube nanowires promote near optimal H* binding energy, thereby releasing the H2 faster. Thus, our approach yields an active low metal loading alkaline HER catalyst without sacrificing the performance in an AEM electrolyser.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Modeling Polyzwitterion-Based Drug Delivery Platforms: A Perspective of the Current State-of-the-Art and Beyond},

author = {Sousa Javan Nikkhah and Matthias Vandichel},

doi = {10.1021/acsengineeringau.2c00008},

year  = {2022},

date = {2022-05-03},

urldate = {2022-05-03},

journal = {ACS Engineering Au},

volume = {2},

pages = {274−294},

abstract = {Drug delivery platforms are anticipated to have biocompatible and bioinert surfaces. PEGylation of drug carriers is the most approved method since it improves water solubility and colloid stability and decreases the drug vehicles’ interactions with blood components. Although this approach extends their biocompatibility, biorecognition mechanisms prevent them from biodistribution and thus efficient drug transfer. Recent studies have shown (poly)zwitterions to be alternatives for PEG with superior biocompatibility. (Poly)zwitterions are super hydrophilic, mainly stimuli-responsive, easy to functionalize and they display an extremely low protein adsorption and long biodistribution time. These unique characteristics make them already promising candidates as drug delivery carriers. Furthermore, since they have highly dense charged groups with opposite signs, (poly)zwitterions are intensely hydrated under physiological conditions. This exceptional hydration potential makes them ideal for the design of therapeutic vehicles with antifouling capability, i.e., preventing undesired sorption of biologics from the human body in the drug delivery vehicle. Therefore, (poly)zwitterionic materials have been broadly applied in stimuli-responsive “intelligent” drug delivery systems as well as tumor-targeting carriers because of their excellent biocompatibility, low cytotoxicity, insignificant immunogenicity, high stability, and long circulation time. To tailor (poly)zwitterionic drug vehicles, an interpretation of the structural and stimuli-responsive behavior of this type of polymer is essential. To this end, a direct study of molecular-level interactions, orientations, configurations, and physicochemical properties of (poly)zwitterions is required, which can be achieved via molecular modeling, which has become an influential tool for discovering new materials and understanding diverse material phenomena. As the essential bridge between science and engineering, molecular simulations enable the fundamental understanding of the encapsulation and release behavior of intelligent drug-loaded (poly)zwitterion nanoparticles and can help us to systematically design their next generations. When combined with experiments, modeling can make quantitative predictions. This perspective article aims to illustrate key recent developments in (poly)zwitterion-based drug delivery systems. We summarize how to use predictive multiscale molecular modeling techniques to successfully boost the development of intelligent multifunctional (poly)zwitterions-based systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.inorgchem.1c03665,

title = {Surprisingly Low Reactivity of Layered Manganese Oxide toward Water Oxidation in Fe/Ni-Free Electrolyte under Alkaline Conditions},

author = {Mahya Salmanion and Ivan Kondov and Matthias Vandichel and Pavlo Aleshkevych and Mohammad Mahdi Najafpour},

url = {https://doi.org/10.1021/acs.inorgchem.1c03665},

doi = {10.1021/acs.inorgchem.1c03665},

year  = {2022},

date = {2022-01-14},

urldate = {2022-01-14},

journal = {Inorganic Chemistry},

volume = {61},

number = {0},

issue = {4},

pages = {2292–2306},

abstract = {So far, many studies on the oxygen-evolution reaction (OER) by Mn oxides have been focused on activity; however, the identification of the best performing active site and corresponding catalytic cycles is also of critical importance. Herein, the real intrinsic activity of layered Mn oxide toward OER in Fe/Ni-free KOH is studied for the first time. At pH ≈ 14, the onset of OER for layered Mn oxide in the presence of Fe/Ni-free KOH happens at 1.72 V (vs reversible hydrogen electrode (RHE)). In the presence of Fe ions, a 190 mV decrease in the overpotential of OER was recorded for layered Mn oxide as well as a significant decrease (from 172.8 to 49 mV/decade) in the Tafel slope. Furthermore, we find that both Ni and Fe ions increase OER remarkably in the presence of layered Mn oxide, but that pure layered Mn oxide is not an efficient catalyst for OER without Ni and Fe under alkaline conditions. Thus, pure layered Mn oxide and electrolytes are critical factors in finding the real intrinsic activity of layered Mn oxide for OER. Our results call into question the high efficiency of layered Mn oxides toward OER under alkaline conditions and also elucidate the significant role of Ni and Fe impurities in the electrolyte in the presence of layered Mn oxide toward OER under alkaline conditions. Overall, a computational model supports the conclusions from the experimental structural and electrochemical characterizations. In particular, substitutional doping with Fe decreases the thermodynamic OER overpotential up to 310 mV. Besides, the thermodynamic OER onset potential calculated for the Fe-free structures is higher than 1.7 V (vs RHE) and, thus, not in the stability range of Mn oxides.},

note = {PMID: 35029976},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/anie.202116145,

title = {The First Sulfate-Pillared Hybrid Ultramicroporous Material, SOFOUR-1-Zn, and Its Acetylene Capture Properties},

author = {Debobroto Sensharma and Daniel J. O'Hearn and Amin Koochaki and Andrey A. Bezrukov and Naveen Kumar and Benjamin H. Wilson and Matthias Vandichel and Michael J. Zaworotko},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202116145},

doi = {https://doi.org/10.1002/anie.202116145},

year  = {2022},

date = {2022-01-02},

urldate = {2022-01-02},

journal = {Angewandte Chemie International Edition},

volume = {61},

pages = {e202116145},

abstract = {Abstract Hybrid ultramicroporous materials, HUMs, are comprised of metal cations linked by combinations of inorganic and organic ligands. Their modular nature makes them amenable to crystal engineering studies, which have thus far afforded four HUM platforms (as classified by the inorganic linkers). HUMs are of practical interest because of their benchmark gas separation performance for several industrial gas mixtures. We report herein design and gram-scale synthesis of the prototypal sulfate-linked HUM, the fsc topology coordination network ([Zn(tepb)(SO4)]n), SOFOUR-1-Zn},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RODRIGUEZOLGUIN2021,

title = {Al2O3 Nanofibers Prepared from Aluminum Di(sec-butoxide)acetoacetic Ester Chelate Exhibits High Surface Area and Acidity},

author = {M. A. Rodriguez-Olguin and H. Atia and M. Bosco and A. Aguirre and R. Eckelt and E. D. Asuquo and M. Vandichel and J. G. E. Gardeniers and A. Susarrey-Arce},

url = {https://www.sciencedirect.com/science/article/pii/S0021951721004796},

doi = {https://doi.org/10.1016/j.jcat.2021.11.019},

issn = {0021-9517},

year  = {2022},

date = {2022-01-01},

urldate = {2021-11-22},

journal = {Journal of Catalysis},

volume = {405},

pages = {520-533},

abstract = {Alumina (Al2O3) is a widely used material for catalysis in the chemical industry. Besides a high specific surface area, acid sites on Al2O3 play a crucial role in the chemical transformation of adsorbed molecules, which ultimately react and desorb from the catalyst. This study introduces a synthetic method based on electrospinning to produce Al2O3 nanofibers (ANFs) with acidity and porosity tuned using different aluminum precursor formulations. After electrospinning and heat treatment, the nanofibers form a non-woven network with macropores (∼4 μm). Nanofibers produced from aluminum di(sec-butoxide)acetoacetic ester chelate (ASB) show the highest total acidity of ca. 0.70 µmol/m2 determined with temperature-programmed desorption of ammonia (NH3-TPD) and BET. The nature of the acid site in ASB ANFs is studied in detail with infrared (IR) spectroscopy. Pyridine is used as a molecular probe for the identification of acid sites in ASB. Pyridine showed the presence of Lewis acid sites prominently. Density-functional theory (DFT) is conducted to understand the desorption kinetics of the adsorbed chemical species, such as ammonia (NH3) on crystalline γ-Al2O3. For our analysis, we focused on a mobile approach for chemisorbed and physisorbed NH3. The computational results are compared with NH3-TPD experiments, ultimately utilized to estimate the desorption energy and kinetic desorption parameters. The experiments are found to pair up with our simulation results. We predict that these non-woven structures will find application as a dispersion medium of metallic particles in catalysis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{KUMAR20213085,

title = {Breaking the trade-off between selectivity and adsorption capacity for gas separation},

author = {Naveen Kumar and Soumya Mukherjee and Nathan C. Harvey-Reid and Andrey A. Bezrukov and Kui Tan and Vinicius Martins and Matthias Vandichel and Tony Pham and Lisa M. Wyk and Kolade Oyekan and Amrit Kumar and Katherine A. Forrest and Komal M. Patil and Leonard J. Barbour and Brian Space and Yining Huang and Paul E. Kruger and Michael J. Zaworotko},

url = {https://www.sciencedirect.com/science/article/pii/S2451929421003636},

doi = {https://doi.org/10.1016/j.chempr.2021.07.007},

issn = {2451-9294},

year  = {2021},

date = {2021-11-11},

urldate = {2021-01-01},

journal = {Chem},

volume = {7},

number = {11},

pages = {3085-3098},

abstract = {Summary The trade-off between selectivity and adsorption capacity with porous materials is a major roadblock to reducing the energy footprint of gas separation technologies. To address this matter, we report herein a systematic crystal engineering study of C2H2 removal from CO2 in a family of hybrid ultramicroporous materials (HUMs). The HUMs are composed of the same organic linker ligand, 4-(3,5-dimethyl-1H-pyrazol-4-yl)pyridine, pypz, three inorganic pillar ligands, and two metal cations, thereby affording six isostructural pcu topology HUMs. All six HUMs exhibited strong binding sites for C2H2 and weaker affinity for CO2. The tuning of pore size and chemistry enabled by crystal engineering resulted in benchmark C2H2/CO2 separation performance. Fixed-bed dynamic column breakthrough experiments for an equimolar (v/v = 1:1) C2H2/CO2 binary gas mixture revealed that one sorbent, SIFSIX-21-Ni, was the first C2H2 selective sorbent that combines exceptional separation selectivity (27.7) with high adsorption capacity (4 mmol·g−1).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ABDI202137774,

title = {The importance of identifying the true catalyst when using Randles-Sevcik equation to calculate turnover frequency},

author = {Zahra Abdi and Matthias Vandichel and Alla S. Sologubenko and Marc-Georg Willinger and Jian-Ren Shen and Suleyman I. Allakhverdiev and Mohammad Mahdi Najafpour},

url = {https://www.sciencedirect.com/science/article/pii/S0360319921035199},

doi = {https://doi.org/10.1016/j.ijhydene.2021.09.039},

issn = {0360-3199},

year  = {2021},

date = {2021-09-29},

urldate = {2021-01-01},

journal = {International Journal of Hydrogen Energy},

volume = {46},

number = {76},

pages = {37774-37781},

abstract = {Water splitting will become important to store excess renewable electrical energy into hydrogen. Although the oxygen-evolution reaction (OER) by water oxidation is a critical reaction for water splitting, further investigations are needed to find the details of the OER mechanism for various electrocatalysts. More in particular for homogeneous electrocatalysts, the Randles-Sevcik equation has been extensively applied to determine the turnover frequency (TOF). Herein, using vitamin B12 as a case study, we show that the dynamical deposition/dissolution of the heterogeneous catalyst during OER makes the Randles-Sevcik equation too complicated to be used for calculating the TOF. Indeed, the conventionally applied post-characterization methods do not provide sufficient accuracy to prove the homogeneity of OER mechanisms; thus, using the Randles-Sevcik equation to calculate the TOF is not necessarily correct.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{D1FD90057A,

title = {Theory and modelling: general discussion},

author = {Dmytro Äntypov and Vonika Ka-Man Au and Isabel Cooley and François-Xavier Coudert and Deanna M. D’Alessandro and Qiaowei Li and Martin Schroder and Mikhail Suyetin and Matthias Vandichel and Sihai Yang and Michael Zaworotko and Elena" Besley},

url = {http://dx.doi.org/10.1039/D1FD90057A},

doi = {10.1039/D1FD90057A},

year  = {2021},

date = {2021-09-29},

urldate = {2021-01-01},

journal = {Faraday Discuss.},

volume = {231},

pages = {258-265},

publisher = {The Royal Society of Chemistry},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.chemmater.1c01723,

title = {Efficient Capture of Trace Acetylene by an Ultramicroporous Metal–Organic Framework with Purine Binding Sites},

author = {Shivani Sharma and Soumya Mukherjee and Aamod V Desai and Matthias Vandichel and Gourab K Dam and Ashwini Jadhav and Gabriele Kociok-Köhn and Michael J Zaworotko and Sujit K Ghosh},

url = {https://doi.org/10.1021/acs.chemmater.1c01723},

doi = {10.1021/acs.chemmater.1c01723},

year  = {2021},

date = {2021-07-09},

urldate = {2021-07-09},

journal = {Chemistry of Materials},

volume = {33},

number = {14},

pages = {5800-5808},

abstract = {Efficient separation of acetylene (C2H2) from its byproducts, especially CO2, is difficult because of their similar physicochemical properties, including molecular dimensions and boiling point. Herein, we demonstrate trace C2H2 removal from C2H2/CO2 mixtures enabled by a new ultramicroporous metal–organic framework (MOF) adsorbent, IPM-101, which features an optimal pore size of 4 Å (close to the kinetic diameter of C2H2, 3.3 Å) and one-dimensional channels lined by Lewis basic purine groups. Single-component gas adsorption isotherms revealed a clear affinity toward C2H2 versus CO2 at low pressures with a substantial C2H2 uptake of 0.9 mmol g–1 at 3000 ppm and 298 K. Dynamic column breakthrough experiments revealed separation of C2H2 from 1:1 and 1:99 v/v C2H2/CO2 mixtures. IPM-101 exhibits one of the highest dynamic separation selectivity (αAC) values yet reported, 22.5 for 1:1 C2H2/CO2. Computational simulations indicated that the purine moiety was key to the strong C2H2 selectivity thanks to C2H2 selective N···HC≡CH interactions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acssuschemeng.1c03539,

title = {Understanding the Dynamics of Molecular Water Oxidation Catalysts with Liquid-Phase Transmission Electron Microscopy: The Case of Vitamin B12},

author = {Zahra Abdi and Esmael S Balaghi and Alla S Sologubenko and Marc-Georg Willinger and Matthias Vandichel and Jian-Ren Shen and Suleyman I Allakhverdiev and Greta R Patzke and Mohammad Mahdi Najafpour},

url = {https://doi.org/10.1021/acssuschemeng.1c03539},

doi = {10.1021/acssuschemeng.1c03539},

year  = {2021},

date = {2021-07-07},

journal = {ACS Sustainable Chemistry & Engineering},

volume = {9},

number = {28},

pages = {9494-9505},

abstract = {Cobalt compounds are intensely explored as efficient catalysts for the oxygen evolution reaction (OER). Since vitamin B12 is a soluble cobalt compound with high enzymatic activity, evaluating its OER activity is of relevance for biomimetic catalyst research. In this work, the temporal evolution of a homogenous vitamin B12 catalyst in the early stages of OER was investigated by an advanced combination of in situ electrochemical liquid transmission electron microscopy (EC-LTEM), in situ UV–vis spectroelectrochemistry, and extended X-ray absorption fine structure (EXAFS) methods. For the first time, we provided direct evidence of diffuse layer dynamics on the working electrode interface. The results suggested that the formation of cobalt oxyphosphate nanoparticles on the working electrode interface and in the presence of phosphate buffer is the initial stage of the catalytic pathway. Computational results confirmed that the ligand oxidation pathway could occur at potentials below the OER thermodynamic barrier (1.23 V vs reversible hydrogen electrode (RHE)), which leads to a Co ion leaching into the electrolyte. This study showed that investigation of the apparent molecular mechanisms of OER with metal complexes requires careful analyses. We illustrate the high precision and sensitivity of EC-LTEM under operational conditions to monitor heterogeneous catalysts generated during OER and to evaluate their actual roles in the catalytic process.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acsami.1c06241,

title = {High Working Capacity Acetylene Storage at Ambient Temperature Enabled by a Switching Adsorbent Layered Material},

author = {Shi-Qiang Wang and Xiao-Qing Meng and Matthias Vandichel and Shaza Darwish and Ze Chang and Xian-He Bu and Michael J Zaworotko},

url = {https://doi.org/10.1021/acsami.1c06241},

doi = {10.1021/acsami.1c06241},

year  = {2021},

date = {2021-05-13},

journal = {ACS Applied Materials & Interfaces},

volume = {13},

number = {20},

pages = {23877-23883},

abstract = {Unlike most gases, acetylene storage is a challenge because of its inherent pressure sensitivity. Herein, a square lattice (sql) coordination network [Cu(4,4′-bipyridine)2(BF4)2]n (sql-1-Cu-BF4) is investigated with respect to its C2H2 sorption behavior from 189 to 298 K. The C2H2 sorption studies revealed that sql-1-Cu-BF4 exhibits multistep isotherms that are temperature-dependent and consistent with the transformation from “closed” (nonporous) to four “open” (porous) phases induced by the C2H2 uptake. The Clausius–Clapeyron equation was used to calculate the performance of sql-1-Cu-BF4 for C2H2 storage at pressures >1 bar, which revealed that its volumetric working capacity at 288 K is slightly superior to acetone (174 vs 170 cm3 cm–3) over a safer pressure range (1–3.5 vs 1–15 bar). Molecular simulations provided insights into the observed switching phenomena, revealing that the layer expansion of sql-1-Cu-BF4 occurs via intercalation and inclusion of C2H2. These results indicate that switching adsorbent layered materials offer promise for utility in the context of C2H2 storage and delivery.},

note = {PMID: 33983706},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.inorgchem.0c03746b,

title = {Oxygen-Evolution Reaction by a Palladium Foil in the Presence of Iron},

author = {Nader Akbari and Ivan Kondov and Matthias Vandichel and Pavlo Aleshkevych and Mohammad Mahdi Najafpour},

url = {https://doi.org/10.1021/acs.inorgchem.0c03746},

doi = {10.1021/acs.inorgchem.0c03746},

year  = {2021},

date = {2021-04-07},

journal = {Inorganic Chemistry},

volume = {60},

number = {8},

pages = {5682–5693},

abstract = {Herein, we investigate the oxygen-evolution reaction (OER) and electrochemistry of a Pd foil in the presence of iron under alkaline conditions (pH ≈ 13). As a source of iron, K2FeO4 is employed, which is soluble under alkaline conditions in contrast to many other Fe salts. Immediately after reacting with the Pd foil, [FeO4]2– causes a significant increase in OER and changes in the electrochemistry of Pd. In the absence of this Fe source and under OER, Pd(IV) is stable, and hole accumulation occurs, while in the presence of Fe this accumulation of stored charges can be used for OER. A Density Functional Theory (DFT) based thermodynamic model suggests an oxygen bridge vacancy as an active site on the surface of PdO2 and an OER overpotential of 0.42 V. A substitution of Pd with Fe at this active site reduces the calculated OER overpotential to 0.35 V. The 70 mV decrease in overpotential is in good agreement with the experimentally measured decrease of 60 mV in the onset potential. In the presence of small amounts of Fe salt, our results point toward the Fe doping of PdO2 rather than extra framework FeOx (Fe(OH)3, FeO(OH), and KFeO2) species on top of PdO2 as the active OER sites.},

note = {PMID: 33826338},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Zhou2021,

title = {Synthesis of Colloidal WSe2 Nanocrystals: Polymorphism Control by Precursor-Ligand Chemistry},

author = {Pengshang Zhou, Pieter Schiettecatte, Matthias Vandichel, Anastasia Rousaki, Peter Vandenabeele, Zeger Hens, and Shalini Singh},

doi = {https://doi.org/10.1021/acs.cgd.0c01036},

year  = {2021},

date = {2021-01-29},

journal = {Crystal Growth & Design},

volume = {21},

number = {3},

pages = {1451-1460},

abstract = {Syntheses of transition-metal dichalcogenides (TMDs) using colloidal-chemistry approaches are gaining significant interest in recent years, as these methods enable the morphology and properties of the nanocrystals to be tuned for targeted applications. In this work, by only varying the ligand used during synthesis, we synthesized nanoflowers with oleic acid (OA) and 1T′ phase dominated WSe2 nanosheets with oleylamine (OLA). WSe2 nanocrystals show slower rate of formation for the metastable 1T′ phase. Surface chemistry analyses of the synthesized nanocrystals by solution NMR establish that neither of the ligands bind strongly to the surface of nanocrystals but are in a dynamic coordination with the WSe2 surface. A further examination of the coordination of tungsten hexacarbonyl (W(CO)6) with the respective ligands confirms that W(CO)6 decomposes in OA, losing its octahedral symmetry, which leads to fast reactivity in the flask. In contrast to this, W(CO)6 reacts with OLA to form a new complex, which leads to slower reactivity and crystallization of the synthesized nanocrystals in the octahedral 1T′ phase. These insights into the influence of precursor-ligand chemistry on reaction outcome and the peculiar surface chemistry of colloidal TMD nanocrystals will be instrumental in developing future colloidal TMD nanocrystals.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000553709000001,

title = {Oxygen Evolution and Reduction on Fe-doped NiOOH: Influence of Solvent,  Dopant Position and Reaction Mechanism},

author = {Matthias Vandichel and Kari Laasonen and Ivan Kondov},

url = {https://doi.org/10.1007/s11244-020-01334-8},

doi = {10.1007/s11244-020-01334-8},

issn = {1022-5528},

year  = {2020},

date = {2020-07-29},

journal = {TOPICS IN CATALYSIS},

abstract = {The oxygen evolution reaction (OER) is the limiting factor in an 

 electrolyzer and the oxygen reduction reaction (ORR) the limiting factor 

 in a fuel cell. In OER, water is converted to O(2)and H+/e(-)pairs, 

 while in ORR the reverse process happens to form water. Both reactions 

 and their efficiency are important enablers of a hydrogen economy where 

 hydrogen will act as a fuel or energy storage medium. OER and ORR can 

 both be described assuming a four-step electrochemical mechanism with coupled H+/e(-)transfers between four intermediates (M-*},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000557552100001,

title = {Water Oxidation at Neutral pH using a Highly Active Copper-Based  Electrocatalyst},

author = {Hussein A Younus and Yan Zhang and Matthias Vandichel and Nazir Ahmad and Kari Laasonen and Francis Verpoort and Ce Zhang and Shiguo Zhang},

doi = {10.1002/cssc.202001444},

issn = {1864-5631},

year  = {2020},

date = {2020-07-15},

journal = {CHEMSUSCHEM},

abstract = {The sluggish kinetics of the oxygen evolution reaction (OER) at the 

 anode severely limit hydrogen production at the cathode in water 

 splitting systems. Although electrocatalytic systems based on cheap and 

 earth-abundant copper catalysts have shown promise for water oxidation 

 under basic conditions, only very few examples with high overpotential 

 can be operated under acidic or neutral conditions, even though hydrogen 

 evolution in the latter case is much easier. This work presents an 

 efficient and robust Cu-based molecular catalyst, which self-assembles 

 as a periodic film from its precursors under aqueous conditions on the 

 surface of a glassy carbon electrode. This film catalyzes the OER under 

 neutral conditions with impressively low overpotential. In controlled 

 potential electrolysis, a stable catalytic current of 1.0 mA cm(-2)can 

 be achieved at only 2.0 V (vs. RHE) and no significant decrease in the 

 catalytic current is observed even after prolonged bulk electrolysis. 

 The catalyst displays first-order kinetics and a single site mechanism 

 for water oxidation with a TOF (k(cat)) of 0.6 s(-1). DFT calculations 

 on of the periodic Cu(TCA)(2)(HTCA=1-mesityl-1H-1,2,3-triazole-4-carboxylic acid) film 

 reveal that TCA defects within the film create Cu(I)active sites that 

 provide a low overpotential route for OER, which involves Cu-I, Cu-II-OH},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000547455300015,

title = {Understanding Solid-Gas Reaction Mechanisms by Operando Soft X-Ray 

 Absorption Spectroscopy at Ambient Pressure},

author = {Luca Braglia and Martina Fracchia and Paolo Ghigna and Alessandro Minguzzi and Daniela Meroni and Raju Edla and Matthias Vandichel and Elisabet Ahlberg and Giuseppina Cerrato and Piero Torelli},

doi = {10.1021/acs.jpcc.0c02546},

issn = {1932-7447},

year  = {2020},

date = {2020-07-01},

journal = {JOURNAL OF PHYSICAL CHEMISTRY C},

volume = {124},

number = {26},

pages = {14202-14212},

abstract = {Ambient-pressure operando soft X-ray absorption spectroscopy (soft-XAS) 

 was applied to study the reactivity of hydroxylated SnO(2 )nanoparticles 

 toward reducing gases. H-2 was first used as a test case, showing that 

 the gas phase and surface states can be simultaneously probed: Soft-XAS 

 at the O K-edge gains sensitivity toward the gas phase, while at the Sn 

 M-4,M-5-edges, tin surface states are explicitly probed. Results 

 obtained by flowing hydrocarbons (CH4 and CH3CHCH2) unequivocally show 

 that these gases react with surface hydroxyl groups to produce water 

 without producing carbon oxides and release electrons that localize on 

 Sn to eventually form SnO. The partially reduced SnO2-x layer at the 

 surface of SnO2 is readily reoxidized to SnO2 by treating the sample 

 with O-2 at mild temperatures (>200 degrees C), revealing the nature of 

 ``electron sponge'' of tin oxide. The experiments, combined with DFT 

 calculations, allowed devising of a mechanism for dissociative 

 hydrocarbon adsorption on SnO2, involving direct reduction of Sn sites 

 at the surface via cleavage of C-H bonds and the formation of methoxy- 

 and/or methyl-tin species at the surface.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000526300600012,

title = {Reversible Switching between Nonporous and Porous Phases of a New SIFSIX 

 Coordination Network Induced by a Flexible Linker Ligand},

author = {Bai-Qiao Song and Qing-Yuan Yang and Shi-Qiang Wang and Matthias Vandichel and Amrit Kumar and Clare Crowley and Naveen Kumar and Cheng-Hua Deng and Victoria GasconPerez and Matteo Lusi and Hui Wu and Wei Zhou and Michael J Zaworotko},

doi = {10.1021/jacs.0c01314},

issn = {0002-7863},

year  = {2020},

date = {2020-04-01},

journal = {JOURNAL OF THE AMERICAN CHEMICAL SOCIETY},

volume = {142},

number = {15},

pages = {6896-6901},

abstract = {Closed-to-open structural transformations in flexible coordination 

 networks are of potential utility in gas storage and separation. Herein, 

 we report the first example of a flexible SiF62--pillared square grid material, [Cu(SiF6)(L)(2)](n) (L = 1,4-bis(1-imidazolyl)benzene), 

 SIFSIX-23-Cu. SIFSIX-23-Cu exhibits reversible switching between 

 nonporous (beta 1) and several porous (alpha, gamma 1, gamma 2, and 

 gamma 3) phases triggered by exposure to N-2, CO2, or H2O. In addition, 

 heating beta 1 to 433 K resulted in irreversible transformation to a 

 closed polymorph, beta 2. Single-crystal X-ray diffraction studies 

 revealed that the phase transformations are enabled by rotation and 

 geometrical contortion of L. Density functional theory calculations 

 indicated that L exhibits a low barrier to rotation (as low as 8 

 kJmol(-1)) and a rather flat energy surface. In situ neutron powder 

 diffraction studies provided further insight into these sorbate-induced 

 phase changes. SIFSIX-23-Cu combines stability in water for over a year, 

 high CO2 uptake (ca. 216 cm(3)/g at 195 K), and good thermal stability.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000505822700001,

title = {Oxygen Evolution on Metal-oxy-hydroxides: Beneficial Role of Mixing Fe,  Co, Ni Explained via Bifunctional Edge/acceptor Route},

author = {Matthias Vandichel and Michael Busch and Kari Laasonen},

doi = {10.1002/cctc.201901951},

issn = {1867-3880},

year  = {2020},

date = {2020-03-01},

journal = {CHEMCATCHEM},

volume = {12},

number = {5},

pages = {1436-1442},

abstract = {Oxygen evolution reaction (OER) via mixed metal oxy hydroxides 

 [M(O)(OH)] may take place on a large variety of possible active sites 

 on the actual catalyst. A single site computational description assumes 

 a 4-step electrochemical mechanism with coupled H+/e(-) transfers between 4 intermediates (M-*, M-OH},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{YOUNUS2020100437,

title = {Engineering of a highly stable metal-organic Co-film for efficient electrocatalytic water oxidation in acidic media},

author = {H A Younus and M Vandichel and N Ahmad and E Ahlberg and M Busch and F Verpoort},

url = {http://www.sciencedirect.com/science/article/pii/S2468606920300563},

doi = {10.1016/j.mtener.2020.100437},

issn = {2468-6069},

year  = {2020},

date = {2020-01-01},

journal = {Materials Today Energy},

volume = {17},

pages = {100437},

abstract = {Water oxidation is traditionally performed over IrO2 and RuO2 owing to their high stability at low pH compared to molecular O2 evolution catalysts. The low stability of molecular complexes in acids limits their industrial exploitation as anodes in water-splitting devices, where high current densities and proton conductivity are required. Herein, an existing Co(1,10-phenanthroline)2 complex film is engineered to improve its pH-stability via extra OH substituents on the ligand, i.e. 1,10-phenanthroline-4,7-diol. This novel Co(1,10-phenanthroline-4,7-diol)2 complex film is active for water oxidation at low overpotentials and stable at low pH. Since the calculated water oxidation overpotentials of both complexes are similar, the difference in water oxidation activity is attributed to a smaller charge transfer resistance, which originates from a different anchoring style to the electrode via the OH groups of the ligand. This result is supported by electrochemical impedance measurements. The high pH-stability of the Co(1,10-phenanthroline-4,7-diol)2 film is computationally rationalized by a high crystal formation energy observed in DFT calculations. In summary, an acid-stable and active cobalt-based metal-organic film is reported that competes well with most reported earth-abundant catalysts for water oxidation under similar conditions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/cctc.202001284,

title = {Microwave-heated γ-Alumina Applied to the Reduction of Aldehydes to Alcohols},

author = {Bhausaheb Dhokale and Arturo Susarrey-Arce and Anna Pekkari and August Runemark and Kasper Moth-Poulsen and Christoph Langhammer and Hanna Härelind and Michael Busch and Matthias Vandichel and Henrik Sundén},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cctc.202001284},

doi = {https://doi.org/10.1002/cctc.202001284},

year  = {2020},

date = {2020-01-01},

journal = {ChemCatChem},

volume = {12},

number = {24},

pages = {6344-6355},

abstract = {Abstract The development of cheap and robust heterogeneous catalysts for the Meerwein-Ponndorf-Verley (MPV) reduction is desirable due to the difficulties in product isolation and catalyst recovery associated with the traditional use of homogeneous catalysts for MPV. Herein, we show that microwave heated γ-Al2O3 can be used for the reduction of aldehydes to alcohols. The reaction is efficient and has a broad substrates scope (19 entries). The products can be isolated by simple filtration, and the catalyst can be regenerated. With the use of microwave heating, we can direct the heating to the catalyst rather than to the whole reaction medium. Furthermore, DFT was used to study the reaction mechanism, and we can conclude that a dual-site mechanism is operative where the aldehyde and 2-propoxide are situated on two adjacent Al sites during the reduction. Additionally, volcano plots were used to rationalize the reactivity of Al2O3 in comparison to other metal oxides.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/smm2.1008,

title = {A square lattice topology coordination network that exhibits highly selective C2H2/CO2 separation performance},

author = {Naveen Kumar and Soumya Mukherjee and Andrey A Bezrukov and Matthias Vandichel and Mohana Shivanna and Debobroto Sensharma and Alankriti Bajpai and Victoria Gascón and Ken-ichi Otake and Susumu Kitagawa and Michael J Zaworotko},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smm2.1008},

doi = {https://doi.org/10.1002/smm2.1008},

year  = {2020},

date = {2020-01-01},

journal = {SmartMat},

volume = {1},

number = {1},

pages = {e1008},

abstract = {Abstract C2H2/CO2 separation is an industrially important process that remains challenging because of the similar physicochemical properties of C2H2 and CO2. We herein report that the new square lattice (sql) coordination network [Cu(bipy-xylene)2(NO3)2]n, sql-16-Cu-NO3, 16 = bipy-xylene = 4,4′-(2,5-dimethyl-1,4-phenylene)dipyridine, exists in at least three forms, as-synthesised (α), activated (α′) and hydrated (β). The activated phase, sql-16-Cu-NO3-α′, is an ultramicroporous material that exhibits high selectivity towards C2H2 over CO2 as revealed by dynamic gas breakthrough experiments (1:1, C2H2/CO2) that afforded 99.87% pure CO2 in the effluent stream. The separation selectivity at 298 K and 1 bar, 78, is the third best value yet reported for C2H2 selective physisorbents whereas the mid-loading performance sets a new benchmark. The performance of sql-16-Cu-NO3-α′ is attributed to a new type of C2H2 binding site in which CH···ONO2 interactions enable moderately strong sorbent-sorbate binding (Qst (C2H2) = 38.6 kJ/mol) at low loading. Conversely, weak CO2 binding (Qst (CO2) = 25.6 kJ/mol) at low loading means that (ΔQst)AC [Qst (C2H2)–Qst (CO2)] is 13 kJ/mol at low coverage and 11.4 kJ/mol at mid-loading. Analysis of in situ powder X-ray diffraction and modelling experiments provide insight into the sorption properties and high C2H2/CO2 separation performance of sql-16-Cu-NO3-α′.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000498288300001,

title = {Viewpoint: Atomic-Scale Design Protocols toward Energy, Electronic, 

 Catalysis, and Sensing Applications},

author = {Florian Belviso and Victor E P Claerbout and Aleix Comas-Vives and Naresh S Dalal and Feng-Ren Fan and Alessio Filippetti and Vincenzo Fiorentini and Lucas Foppa and Cesare Franchini and Benjamin Geisler and Luca M Ghiringhelli and Axel Gross and Shunbo Hu and Jorge Iniguez and Steven Kaai Kauwe and Janice L Musfeldt and Paolo Nicolini and Rossitza Pentcheva and Tomas Polcar and Wei Ren and Fabio Ricci and Francesco Ricci and Huseyin Sener Sen and Jonathan Michael Skelton and Taylor D Sparks and Alessandro Stroppa and Andrea Urru and Matthias Vandichel and Paolo Vavassori and Hua Wu and Ke Yang and Hong Jian Zhao and Danilo Puggioni and Remedios Cortese and Antonio Cammarata},

doi = {10.1021/acs.inorgchem.9b01785},

issn = {0020-1669},

year  = {2019},

date = {2019-11-01},

journal = {INORGANIC CHEMISTRY},

volume = {58},

number = {22},

pages = {14939-14980},

abstract = {Nanostructured materials are essential building blocks for the 

 fabrication of new devices for energy harvesting/storage, sensing, 

 catalysis, magnetic, and optoelectronic applications. However, because 

 of the increase of technological needs, it is essential to identify new 

 functional materials and improve the properties of existing ones. The 

 objective of this Viewpoint is to examine the state of the art of 

 atomic-scale simulative and experimental protocols aimed to the design 

 of novel functional nanostructured materials, and to present new 

 perspectives in the relative fields. This is the result of the debates 

 of Symposium I ``Atomic-scale design protocols towards energy, 

 electronic, catalysis, and sensing applications'', which took place 

 within the 2018 European Materials Research Society fall meeting.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000474796600046,

title = {Initial Fe3O4(100) Formation on Fe(100)},

author = {Markus Soldemo and Matthias Vandichel and Henrik Gronbeck and Jonas Weissenrieder},

doi = {10.1021/acs.jpcc.9b04625},

issn = {1932-7447},

year  = {2019},

date = {2019-07-01},

journal = {JOURNAL OF PHYSICAL CHEMISTRY C},

volume = {123},

number = {26},

pages = {16317-16325},

abstract = {The initial oxidation of Fe(100) at 400 degrees C has been studied by 

 X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy 

 (STM), and low-energy electron diffraction, in combination with density 

 functional theory calculations. The first observed well-ordered surface 

 oxide is formed at a coverage of similar to 3 oxygen atoms per 

 unreconstructed surface Fe(100) atom. STM shows that this surface oxide 

 is terminated by straight atomic rows exhibiting a p(2 X 1) periodicity. 

 However, already for oxide films with a coverage of similar to 4 oxygen 

 atoms (corresponding to one Fe3O4 unit cell thickness), wiggly atomic 

 rows appear similar to the c(2 X 2) reconstructed Fe3O4 (100)-surface 

 with the Fe3O4 unit vectors rotated 45 degrees to Fe(100). The wiggly 

 rows are a consequence of subsurface cation iron vacancies, which 

 previously have been observed for bulk surfaces. The formation of 

 subsurface vacancies is supported by the XPS O is signature, which is 

 modeled by considering the core-level shifts for all oxygen atoms in the 

 film. Throughout the oxidation series, the microscopy results reveal a 

 layer-by-layer (Frank-van der Merwe) growth.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000459731200013,

title = {A dimer path for CO dissociation on PtSn},

author = {Matthias Vandichel and Henrik Gronbeck},

doi = {10.1039/c8cy01989d},

issn = {2044-4753},

year  = {2019},

date = {2019-02-01},

journal = {CATALYSIS SCIENCE & TECHNOLOGY},

volume = {9},

number = {3},

pages = {695-701},

abstract = {Density functional theory calculations are used to investigate CO 

 adsorption, dissociation and SnOX formation on Pt3Sn. We find that 

 direct CO dissociation is prevented by high activation energies. An 

 energetically feasible path is instead CO dimer formation followed by 

 C-O bond cleavage. Dimers are formed in the presence of Sn adatoms which 

 effectively stabilize anionic OCCO- species. The presence of Sn adatoms 

 is crucial as dimers are unstable on Pt-only systems. The proposed 

 mechanism may explain recent experimental observations of SnOX and C-C 

 formation as PtxSn is exposed to CO.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000445805100009,

title = {CO Oxidation at SnO2/Pt3Sn(111) Interfaces},

author = {Matthias Vandichel and Henrik Gronbeck},

doi = {10.1007/s11244-018-1044-9},

issn = {1022-5528},

year  = {2018},

date = {2018-09-01},

journal = {TOPICS IN CATALYSIS},

volume = {61},

number = {14, SI},

pages = {1458-1464},

abstract = {Segregation induced formation of oxide/metal interfaces can 

 significantly influence the catalytic activity of alloy nanoparticles. 

 One example is Pt3Sn nanoparticles, which are known to segregate into 

 SnOX and an Sn deficient alloy phase during typical operating conditions 

 for CO oxidation. Here, we use density functional theory calculations to 

 investigate CO oxidation over Pt3Sn(111) supported SnO2 and (SnO2)(3), 

 representing the initial state of segregation. The results are compared 

 to CO oxidation at an interface between bulk-like SnO2 and Pt3Sn(111). 

 The barrier for CO oxidation via a Mars-van Krevelen mechanism is found 

 to be lower on SnO2 and (SnO2)(3) as compared to the bulk-like model. 

 However, the regeneration of the finite systems is associated with 

 higher barriers for O-2 dissociation which may become the rate limiting 

 step in the low temperature regime where the metal surface can be 

 assumed to be CO covered.},

note = {13th European Congress on Catalysis - A Bridge to the Future, Florence, 

 ITALY, AUG 27-31, 2017},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000442064100014,

title = {Favourable band edge alignment and increased visible light absorption in 

 beta-MoO3/alpha-MoO3 oxide heterojunction for enhanced 

 photoelectrochemical performance},

author = {Nisha Kodan and Aadesh P Singh and Matthias Vandichel and Bjorn Wickman and B R Mehta},

doi = {10.1016/j.ijhydene.2018.06.138},

issn = {0360-3199},

year  = {2018},

date = {2018-08-01},

journal = {INTERNATIONAL JOURNAL OF HYDROGEN ENERGY},

volume = {43},

number = {33},

pages = {15773-15783},

abstract = {Optimum band gap values, favourable band edge positions and stability in 

 the electrolyte are critical parameters required for a semiconductor to 

 have efficient photoelectrode properties. The present investigation 

 carried out on the phase pure alpha & beta MoO3 thin film shows that 

 the low bandgap beta-MoO3 possesses a mis-alignment with the water 

 oxidation potential, while a more suitable band alignment is observed 

 for the comparatively large bandgap alpha-MoO3. Both experimental and 

 DFT calculations show that the valence edge of the orthorhombic 

 (alpha-MoO3) phase is located at a higher energy (0.9 eV higher in 

 VB-XPS and 1 eV higher in the DOS plots) than the monoclinic (beta-MoO3) 

 phase, while the conduction edge value is roughly at the same energy 

 level (-2.5 eV) in both polymorphs. Based on the above investigations, 

 an all oxide heterojunction comprising of beta-MoO3/alpha-MoO3 is found 

 to be suitable for improved PEC performance due to favourable energy 

 band diagram and increased visible light absorption in beta-MoO3. 

 Significantly higher cathodic photocurrent is observed for the 

 beta-MoO3/alpha-MoO3 (1.6 mA/cm(2) at applied bias of -0.3V(RHE) under 

 simulated 1 sun irradiation) as compared to the very low anodic response 

 in beta-MoO3 (similar to 1.0 nA/cm(2)) and alpha-MoO3 (32 mu A/cm(2)). 

 (C) 2018 Published by Elsevier Ltd on behalf of Hydrogen Energy 

 Publications LLC.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000414724700006,

title = {Catalysis at the Rim: A Mechanism for Low Temperature CO Oxidation over 

 Pt3Sn},

author = {Matthias Vandichel and Alina Moscu and Henrik Gronbeck},

doi = {10.1021/acscatal.7b02094},

issn = {2155-5435},

year  = {2017},

date = {2017-11-01},

journal = {ACS CATALYSIS},

volume = {7},

number = {11},

pages = {7431-7441},

abstract = {Metal alloying is commonly used as a design strategy for catalyst 

 optimization. The mechanistic understanding of this class of systems is, 

 however, obscured by reaction induced segregation phenomena. Herein, the 

 case of CO oxidation over Pt3Sn is investigated using density functional 

 theory calculations combined with ab initio thermodynamics and 

 first-principles based microkinetic modeling. It is found that Pt3Sn 

 segregates under typical operating conditions into SnOx and an Sn 

 deficient metal phase. The segregation is driven both by the stability 

 of the metal oxide and the strong bonding of CO to Pt. The catalytic 

 consequences of a metal supported SnO2 phase are explored by comparing 

 CO oxidation at an SnOx/Pt interface with oxidation over Pt and Pt/Pt3Sn 

 skin models. The reaction is found to proceed with lower barriers at the 

 interface as compared to the metal-only systems and the cocatalytic role 

 of the SnOx rim is manifested by low temperature activity. The present 

 work highlights the effects of reaction-induced metaloxide/metal 

 interfaces and elucidates the role of Sn in PtSn alloys for CO oxidation 

 reactions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000398182300008,

title = {A Robust Molecular Catalyst Generated In Situ for Photoand 

 Electrochemical Water Oxidation},

author = {Hussein A Younus and Nazir Ahmad and Adeel H Chughtai and Matthias Vandichel and Michael Busch and Kristof Van Hecke and Mekhman Yusubov and Shaoxian Song and Francis Verpoort},

doi = {10.1002/cssc.201601477},

issn = {1864-5631},

year  = {2017},

date = {2017-03-01},

journal = {CHEMSUSCHEM},

volume = {10},

number = {5},

pages = {862-875},

abstract = {Water splitting is the key step towards artificial photosystems for 

 solar energy conversion and storage in the form of chemical bonding. The 

 oxidation of water is the bottle-neck of this process that hampers its 

 practical utility; hence, efficient, robust, and easy to make catalytic 

 systems based on cheap and earth-abundant materials are of exceptional 

 importance. Herein, an in situ generated cobalt catalyst, 

 [Co-II(TCA)(2)(H2O)(2)] (TCA=1-mesityl-1,2,3-1H-triazole-4-carboxylate), that efficiently 

 conducts photochemical water oxidation under near-neutral conditions is 

 presented. The catalyst showed high stability under photolytic 

 conditions for more than 3 h of photoirradiation. During electrochemical 

 water oxidation, the catalytic system assembled a catalyst film, which 

 proved not to be cobalt oxide/hydroxide as normally expected, but 

 instead, and for the first time, generated a molecular cobalt complex 

 that incorporated the organic ligand bound to cobalt ions. The catalyst 

 film exhibited a low overpotential for electrocatalytic water oxidation 

 (360 mV) and high oxygen evolution peak current densities of 9 and 2.7 

 mA cm(-2) on glassy carbon and indium-doped tin oxide electrodes, 

 respectively, at only 1.49 and 1.39 V ( versus a normal hydrogen 

 electrode), respectively, under neutral conditions. This finding, 

 exemplified on the in situ generated cobalt complex, might be applicable 

 to other molecular systems and suggests that the formation of a 

 catalytic film in electrochemical water oxidation experiments is not 

 always an indication of catalyst decomposition and the formation of 

 nanoparticles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000394359600017,

title = {Inserting CO2 into Terminal Alkynes via Bis-(NHC)-Metal Complexes},

author = {Heriberto Diaz Velazquez and Zhao-Xuan Wu and Matthias Vandichel and Francis Verpoort},

doi = {10.1007/s10562-016-1920-5},

issn = {1011-372X},

year  = {2017},

date = {2017-02-01},

journal = {CATALYSIS LETTERS},

volume = {147},

number = {2},

pages = {463-471},

abstract = {The direct interaction between CO2 and terminal alkynes in the presence 

 of bis-(NHC)-metal catalysts at ambient conditions was studied. Two Cu 

 and Ag-based bis-N-heterocyclic carbene Transition Metal catalysts were 

 synthesized. The (NHC)(2)-Ag complex showed a better catalytic 

 performance towards the carboxylation of terminal alkynes in comparison 

 with the copper analogue even for the conversion of acetylene gas. The 

 optimized conditions for the carboxylation are: the use of Cs2CO3 as 

 additive, one atmosphere CO2 and room temperature using 1% mol 

 catalyst. Mechanistic insight into the reaction mechanism is obtained by 

 means of state-of-the-art first principles calculations. 

 [GRAPHICS] 

 .},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000378949800022,

title = {Biocompatible Zr-based nanoscale MOFs coated with modified poly 

 (epsilon-caprolactone) as anticancer drug carriers},

author = {Maria Filippousi and Stuart Turner and Karen Leus and Panoraia I Siafaka and Eirini D Tseligka and Matthias Vandichel and Stavroula G Nanaki and Ioannis S Vizirianakis and Dimitrios N Bikiaris and Pascal Van der Voort and Gustaaf Van Tendeloo},

doi = {10.1016/j.ijpharm.2016.05.048},

issn = {0378-5173},

year  = {2016},

date = {2016-07-01},

journal = {INTERNATIONAL JOURNAL OF PHARMACEUTICS},

volume = {509},

number = {1-2},

pages = {208-218},

abstract = {Nanoscale Zr-based metal organic frameworks (MOFs) UiO-66 and UiO-67 

 were studied as potential anticancer drug delivery vehicles. Two model 

 drugs were used, hydrophobic paclitaxel and hydrophilic cisplatin, and 

 were adsorbed onto/into the nano MOFs (NMOFs). The drug loaded MOFs were 

 further encapsulated inside a modified poly(epsilon-caprolactone) with 

 D-alpha-tocopheryl polyethylene glycol succinate polymeric matrix, in 

 the form of microparticles, in order to prepare sustained release 

 formulations and to reduce the drug toxicity. The drugs physical state 

 and release rate was studied at 37 degrees C using Simulated Body Fluid. 

 It was found that the drug release depends on the interaction between 

 the MOFs and the drugs while the controlled release rates can be 

 attributed to the microencapsulated formulations. The in vitro antitumor 

 activity was assessed using HSC-3 (human oral squamous carcinoma; head 

 and neck) and U-87 MG (human glioblastoma grade IV; astrocytoma) cancer 

 cells. Cytotoxicity studies for both cell lines showed that the polymer 

 coated, drug loaded MOFs exhibited better anticancer activity compared 

 to free paclitaxel and cisplatin solutions at different concentrations. 

 (C) 2016 Elsevier B.V. All rights reserved.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000384465500012,

title = {Water coordination and dehydration processes in defective UiO-66 type 

 metal organic frameworks},

author = {M Vandichel and J Hajek and A Ghysels and A De Vos and M Waroquier and V Van Speybroeck},

doi = {10.1039/c6ce01027j},

issn = {1466-8033},

year  = {2016},

date = {2016-01-01},

journal = {CRYSTENGCOMM},

volume = {18},

number = {37},

pages = {7056-7069},

abstract = {The UiO-66 metal organic framework is one of the most thermally and 

 chemically stable hybrid materials reported to date. However, it is also 

 accepted that the material contains structurally embedded defects, which 

 may be engineered to enhance properties towards specific applications 

 such as catalysis, sensing, etc. The synthesis conditions determine to a 

 large extent the level of perfection of the material and additionally 

 the catalytic activity may be enhanced by post-synthesis activation at 

 high temperature under vacuum, in which defect coordinating species 

 (H2O, HCl, monocarboxylic modulators, etc.) evaporate. The molecular 

 level characterization of defects is extremely challenging from both 

 theoretical and experimental points of view. Such experimental endeavor 

 was recently proposed via experimental SXRD measurements, also 

 unraveling the coordination of water on the Zr-O-Zr defect sites 

 [Angew. Chem., Int. Ed., 2015, 54, 11162-11167]. The present work 

 provides a theoretical understanding of defect structures in UiO-66(Zr) 

 by means of periodic density functional theory calculations and ab 

 initio molecular dynamics simulations. A range of defect structures are 

 generated with different numbers of missing linkers. For each of the 

 defects, the free energetic and mechanical stability is discussed and 

 the coordination of water and charge balancing hydroxide ions is 

 studied. For catalysis applications, the material is mostly pretreated 

 to remove water by dehydration reactions. For each of the proposed 

 defect structures, mechanistic pathways for dehydration reactions of the 

 Zr-bricks are determined employing nudged elastic band (NEB) 

 calculations. During the dehydroxylation trajectory, loose hydroxyl 

 groups and terephthalate decoordinations are observed. Furthermore, 

 dehydration reactions are lower activated if terephthalate linkers are 

 missing in the immediate environment of the inorganic brick. The 

 creation of defects and the dehydration processes have a large impact on 

 the mechanical properties of the material, which is evidenced by lower 

 bulk moduli and elastic constants for structures with more defects.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000371710500004,

title = {Origin of highly active metal-organic framework catalysts: defects? 

 Defects!},

author = {J Canivet and M Vandichel and D Farrusseng},

doi = {10.1039/c5dt03522h},

issn = {1477-9226},

year  = {2016},

date = {2016-01-01},

journal = {DALTON TRANSACTIONS},

volume = {45},

number = {10},

pages = {4090-4099},

abstract = {This article provides a comprehensive review of the nature of catalytic 

 sites in MOFs. In the last decade, a number of striking studies have 

 reported outstanding catalytic activities of MOFs. In all cases, the 

 authors were intrigued as it was unexpected from the ideal structure. We 

 demonstrate here that (surface) defects are at the origin of the 

 catalytic activities for the reported examples. The vacancy of ligands 

 or linkers systematically generates (surface) terminations which can 

 possibly show Lewis and/or Bronsted acido-basic features. The 

 engineering of catalytic sites at the nodes by the creation of defects 

 (on purpose) appears today as a rational approach for the design of 

 active MOFs. Similarly to zeolite post-treatments, post-modifications of 

 MOFs by linker or metal cation exchange appear to be methods of choice. 

 Despite the mild acidity of defective MOFs, we can account for very 

 active MOFs in a number of catalytic applications which show higher 

 performances than zeolites or benchmark catalysts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ISI:000364250800001,

title = {Mechanistic studies of aldol condensations in UiO-66 and UiO-66-NH2 

 metal organic frameworks},

author = {Julianna Hajek and Matthias Vandichel and Ben Van de Voorde and Bart Bueken and Dirk De Vos and Michel Waroquier and Veronique Van Speybroeck},

doi = {10.1016/j.jcat.2015.08.015},

issn = {0021-9517},

year  = {2015},

date = {2015-11-01},

journal = {JOURNAL OF CATALYSIS},

volume = {331},

pages = {1-12},

abstract = {A full mechanistic investigation is proposed for the industrially 

 important cross-aldol condensation reaction of heptanal with 

 benzaldehyde on the UiO-66 and the amino-functionalized UiO-66-NH2 

 metal-organic frameworks to form jasminaldehyde. Several experimental 

 studies indicate that the activity for the aldol condensation reaction 

 can be increased by proper functionalization of the material, e.g. by 

 introducing an additional basic amino site and thus creating a 

 bifunctional acid-base catalyst for the aldol condensation. The precise 

 molecular level origin for this behavior is to date unclear. Herein 

 state-of-the-art Density-Functional Theory (DFT) calculations have been 

 performed to unravel the mechanism of the cross- and self-aldol 

 condensations of benzaldehyde and propanal. To this end free energy 

 calculations have been performed on both extended cluster and periodic 

 models. It is found that the mechanism on both catalysts is essentially 

 the same, although a slightly stronger adsorption of the reactants and 

 slightly lower barriers were found on the amino functionalized material, 

 pointing toward higher initial activities. New experiments were 

 performed to confirm these observations. It is indeed found that the 

 initial activity toward cross-aldol condensation on the amino 

 functionalized material is higher, although after about 40 min of 

 reaction both materials become equally active. Our results furthermore 

 point out that the basic amino groups may promote side reactions such as 

 imine formation, which is induced by water. The study as presented can 

 assist to engineer materials at the molecular level toward the desired 

 products. (C) 2015 Elsevier Inc. All rights reserved.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}