Dresden 2011 – scientific programme

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O: Fachverband Oberflächenphysik

O 60: Poster Session IV (Solid/liquid interfaces; Semiconductors; Oxides and insulators; Graphene; Plasmonics and nanooptics; Electronic Structure; Surface chemical reactions; Heterogeneous catalysis)

O 60.120: Poster

Wednesday, March 16, 2011, 17:30–21:00, P4

Methanol synthesis over binary Cu/ZnO surfaces: exploration of energy surfaces for determining adsorption sites for CO₂ — •luis martínez suárez¹, johannes frenzel¹, bernd meyer², and dominik marx¹ — ¹Ruhr University Bochum, Theoretical Chemistry, Bochum, Germany — ²Interdisziplinäres Centrum für Molekulare Materialien (ICMM) and ComputerChemieCentrum (CCC), Department Chemie und Pharmazie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany

Methanol is synthesized from syngas over Cu/ZnO in a heterogeneous catalytic process with CO₂ as carbon source. Atomistic insight into the strong metal substrate interaction (SMSI) effect in Cu/ZnO catalysts has been obtained in a static picture. Calculations of surface phase diagrams by ab initio-thermodynamics determined realistic structures of a small Cu₈ cluster on ZnO(0001) in a hydrogen atmosphere with temperature and pressure conditions as required in the industrial process. These structures are stabilized by the interplay of structural changes as a result of redox properties of the syngas with realistic saturation of the catalyst surface by hydrogen interacting with defect sites. Herein the global energy landscape of the CO₂ reactant over several thermodynamically relevant catalyst surface structures is explored with spatial resolution employing density functional theory. After having identified all possible adsorption sites on the complex Cu/ZnO surfaces the adsorption modes of the complexes are refined investigating their individual structures.