The effects of near-surface atomic order on the catalytic properties of Cu3Au and CuAu3 intermetallics for the CO2 reduction reaction

Abstract

Density functional theory (DFT) calculations combined with cluster expansions (CE) were employed to explore the catalytic activity of stoichiometric and non-stoichiometric Cu₃Au(100), Cu₃Au(111), CuAu₃(100), and CuAu₃(111) surfaces for CO₂ reduction to CO. We identified several adsorption sites which otherwise would not be considered using slab models generated by cleaving ordered bulk structures. For Cu₃Au(111) and CuAu₃(111), the adsorption sites with the highest and lowest estimated onset potential values found through our approach would be missed if modeled from bulk-derived slabs, showing the ability of our strategy to explore the richness of alloy catalysts that arises from the formation of near-surface atomic ordering effects. Finally, we performed simulated annealing calculations based on CE fit to predict CO and COOH adsorption energies. This analysis led us to find adsorption site ensembles that can deviate from the linear scaling relationship that usually hinders the discovery of more active and selective catalysts for CO production.