Talk given by Prof. Bernd Meyer Although methanol synthesis from CO and H2 over ZnO catalysts is a rather simple chemical reaction, the interplay of physical and chemical processes at the ZnO surfaces give rise to a complex free energy landscape. The preferred charge state of oxygen vacancies is dictated by the chemical composition and the thermodynamic properties of the gas phase in contact with ZnO. In turn, reaction intermediates and pathways along the catalytic cycle taking place at or close to these defects depend in a sensitive way on their oxidation state. Instead of constructing the potential energy landscape for this reaction 'by hand' using static DFT and NEB calculations as traditionally done, it will be shown that the underlying complex reaction network from CO to methanol can be generated based on ab-initio metadynamics simulations. In addition to be able to `synthesize' all previously discussed reaction intermediates, novel species are found and mechanistic insights into the reaction network of this surface chemical reaction are obtained by a global exploration of the free energy landscape. In a second step, the global picture is refined by investigating individual reaction pathways, taking into account different charge states of the oxygen vacancies. Finally, first insights into the structure and reactivity of the much more complex Cu/ZnO catalyst, which is subject to so-called 'strong metal support interactions' (SMSI), will be presented.

This event is part of the eventgroup INT Talks

Homepage
https://www.int.kit.edu/events.php

Speaker
Prof. Bernd Meyer

FAU Erlangen-Nürnberg
Interdisciplinary Center for Molecular Materials (ICMM) and Computer-Chemistry-Center (CCC)

Organizer
PD Dr. Karin Fink
Institute of Nanotechnology (INT)
Karlsruhe Institute of Technology (KIT)
Eggenstein-Leopoldshafen
Mail: karin fink ∂does-not-exist.kit edu

Targetgroup
Interested / Everyone