Ideal Site Geometry for Heterogeneous Catalytic Reactions: A DFT Study

Surface geometry at the atomic level is an important factor related to the activity of a catalytic site. It is important to identify sites with high activity to comprehend the performance of a given catalyst. In this work, it is proposed that the optimal surface for a given reaction step should satisfy the condition ∂E∂xi|TS=0, where E is the transition state energy and xi is any variable characterizing the surface. Taking three elementary steps as examples, it is shown that the optimal site found by this method has significantly reduced TS (transition state) energy compared with facets commonly applied in previous studies, and, thus, it can be several orders more active. The method provides an insight into the geometric impact of catalysis, gives a blueprint for an ideal catalyst surface structure, and, thus, provides guidance for catalyst development.