Introducing structural sensitivity into adsorption-energy scaling relations by means of coordination numbers.

Abstract

The search for improved heterogeneous catalysts is an important but difficult task. Scaling relations between the adsorption energies of reaction intermediates greatly facilitate the computational design of catalysts. However, this methodology does not currently incorporate structure sensitivity and hence cannot describe adequately the overall activity of realistic catalyst particles and extended surfaces with several facets, edges and apices. Here, we generalize scaling relations by examining twelve different low-index, stepped and kinked surfaces of nine transition metals. This allows us to quantify the effect of the adsorption-site geometry on these relations, ensures a full prediction of their parameters, and helps in identifying intrinsic thermodynamic restrictions to the performance of catalysts. The resulting fully predictable, structure-sensitive scaling relations are a step towards the long-sought rational design of multifaceted catalytic particles. Such a design can now target not only the chemical nature of active materials but also the actual geometry of their active sites.