Abstracts Book - IMRC 2018

• SF3-O019
Ab INITIO STUDY OF CO2 HYDROGENATION MECHANISMS ON
INVERSE ZnO/Cu CATALYSTS
Michael Walter 1
1 Universität Freiburg, FIT Freiburg Centre for Interactive Materials and Bioinspired
Technologies, Germany.
Mankind is facing considerable challenges in their quest to secure sufficient
energy supply for the future and to solve the global warming problem. Two
central challenges can be completed by formation of methanol CO 2 and
molecular hydrogen produced with renewable energy sources. This reaction is
studied on ZnO/Cu catalysts by gradient corrected density functional theory. The
catalytically active region is modeled as a minimum size inverse catalyst
represented by Zn X O Y (H) clusters of different size and a ZnO nano-ribbon on an
extended Cu(111) surface. These systems are chosen as a representative of
thermodynamically stable catalyst structures under typical reaction conditions.
Comparison to a high level wave function method reveals that density functional
theory systematically underestimates reaction barriers, but nevertheless
conserves their energetic ordering. In contrast to other metal-supported oxides
like ceria and zirconia, the reaction proceeds through the formation of formate
on ZnO X /Cu, thus avoiding the CO intermediate. The difference between the
oxides is attributed to variance in the initial activation of CO 2 . The energetics of
the formate reaction pathway is insensitive to the exact environment of
undercoordinated Zn active sites, which points to a general mechanism for Cu-
Zn based catalysts
1 Thomas Reichenbach, Krishnakanta Mondal, Marc Jäger, Thomas Vent-
Schmidt, Daniel Himmel, Valentin Dybbert, Albert Bruix, Ingo Krossing, Michael
Walter, Michael Moseler J. Catalysis 360 (2018) 168–174
Keywords: CO2 conversion, Methanol, Inverse catalyst
Presenting authors email: Michael.Walter@fmf.uni-freiburg.de