Catalysis Modelling Group (CMG)

Research Areas

Transition metal clusters

TM Cluster

Clusters constitute a state of matter intermediate between molecules and solids. Physical and chemical properties of clusters, which range from sub-nanometer to about 1 micrometer, are size-dependent and thus tunable. This fact is of particular interest in materials science, catalysis and other fields of applied sciences such as nanoelectronics. With our research we contribute at determining chemical properties, reactivity, composition and structures of metal clusters.


  • V. Yudanov, A. Genest, S. Schauermann, H.-J. Freund, N. Rösch:
    Size-Dependence of the Adsorption Energy of CO on Metal Nanoparticles: A DFT Search for the Minimum Value, Nano Letters 12, 2134-2149 (2012); DOI:10.1021/nl300515z.

Conversion of biomass to adipic acid

Adipic Acid Chemistry

Adipic acid (AA) is an important platform molecule in chemical industry, e.g., a precursor for nylon-6,6. A promising way for the clean synthesis of AA starts with non-food derived, abundant and renewable biomass feedstocks, e.g., gamma-Valerolactone (GVL). Experimentally, a Pd complex proved to be a good catalyst for the conversion of pentenoic acid (PEA) isomers (from GVL) to AA, but the mechanism is still unclear. With computational methods we aim at gaining insight into the reaction mechanism. In-depth mechanistic understanding could help experimentalists to design a catalyst that offers a more efficient conversion.

Activation of small molecule in conjugation with metal-ligand redox chemistry

Small molecules like H2, N2 and O2 are ubiquitous reservoirs of chemical energy. Transformation of such molecules with the aid of metal complexes to useful chemicals has wide application, ranging from pharmaceuticals to manufacturing petroleum products. Recently, transition metal-mediated selective oxidation involving redox-active ligands attracts great interest. Molecular oxygen is an ideal inexpensive oxidant for aerobic partial oxidations of organic substrates. Improved insight into pertinent reaction mechanisms will open the door to a new class of catalysts with great potentiality.

Mixed Metal Oxides

MMO

Mixed metal oxides (MMOs) are an important class of materials in oxidation catalysis. Prominent processes of industrial importance are the oxidation of propane to acrylic acid and the ammoxidation of propane to acrylonitrile. Due to the open-shell electronic structure of the intermediates involved in the catalytic processes, standard semi-local DFT methods are only partly suitable for the description of such reactions. We are interested in accurately exploring the chemical reactivity of MMOs.

  • L.-L. Zhao, C.-c. Chiu, A. Genest, N. Rösch DFT cluster model study of MoVO-type mixed-metal oxides, Comp. Theor. Chem. 1045, 57-65 (2014); DOI: 10.1016/j.comptc.2014.06.016.

Biomass conversion

Utilization of biomass, in analogy to fossil carbon, as source of fuel and other chemicals, will be one of the future key technologies to ensure sustainable resources. The structure and chemical properties of biomass differ significantly from those of fossil oil, as the former features a large number of functional groups. In consequence, petro-chemical processes for producing chemicals and fuels are not applicable to biomass processing, new processes need to be developed. On the other hand, establishing novel and more efficient processes for biomass offer new challenges to catalysis research.

Sugars and lignin, the most abundant biomass materials, are characterized by their large number of oxygen functionalities. Removal of these oxygen groups is essential for many applications of biomass, e.g. as bio-fuel. We study molecular processes occurring in metal-catalyzed hydrodeoxygenation of model molecules, e.g., ethanol or guaiacol, which are representative of biomass-derived feedstocks.

C.-c. Chiu, A. Genest, A. Borgna, N. Rösch Hydrodeoxygenation of Guaiacol over Ru(0001). A DFT Study, ACS Catal. 4 (11), 4178-4188 (2014); DOI: 10.1021/cs500911j.

Biomass-derived alcohol is an attractive renewable alternative to petroleum-based feedstock for the production of olefins, an important class of base chemicals used for the production of fuels and fine chemicals. The conversion of alcohols to olefins is typically an acid catalyzed reaction. Thus, for their varying acidity and porosity, zeolites are potential candidate catalysts for the conversion of alcohols to olefins. We model these transformations to unravel this complex reaction network.


S. Dinda, A. Govindasamy, A. Genest, N. Rösch Modeling Catalytic Steps on Extra-Framework Metal Centers in Zeolites. A Case Study on Ethylene Dimerizatio, J. Phys. Chem. C 118 (43), 25077-25088 (2014) DOI: 10.1021/jp508141q.


C.-c. Chiu, G. N. Vayssilov, A. Genest, A. Borgna, N. Rösch Predicting Adsorption Enthalpies on Silicalite and HZSM-5. A Benchmark Study on DFT Strategies Addressing Dispersion Interactions, J. Comp. Chem. 35, 809-819 (2014) DOI: 10.1002/jcc.23558.