Regensburg 2016 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 31: Heterogeneous Catalysis: Theory
O 31.1: Vortrag
Dienstag, 8. März 2016, 10:30–10:45, S053
Analyzing the case for bifunctional catalysis — •Mie Andersen1, Andrew J. Medford2,3, Jens K. Nørskov2,3, and Karsten Reuter1 — 1Theoretical Chemistry, Technische Universität München, Germany — 2SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, CA, USA — 3Department of Chemical Engineering, Stanford University, CA, USA
Computational screening based on scaling relations has proven highly successful in rationalizing, why efficient catalysts are often found within only a narrow range of binding energies that allow the dissociation of reactants without hindering the formation of products [1]. It has been suggested that these severe limitations in material space could be overcome by bifunctional catalysts, which couple two active sites, each catalyzing a particular reaction step. Using global optimization techniques and microkinetic modeling in the mean-field (MF) approximation, we explore the theoretical limits for such a bifunctional gain for a wide range of model reactions. This analysis suggests that bifunctional catalysts made from two active sites of similar type, i.e. controlled by similar scaling relations, will in general not reach higher activities than single-site catalysts. We correspondingly aim to quantify how "different" the two active sites must be in order for the idea of bifunctionality to work.
[1] J. K. Nørskov et al., Nature Chem. 1, 37 (2009)