Nonequilibrium ab initio modeling of electrocatalysis

Theoretical modeling of electrocatalysis often employs density functional theory (DFT) based approaches, which have achieved remarkable success in qualitatively explaining complex experimental observations over the past few decades. One main issue with DFT modeling of electrochemical reactions is that the systems inherently involve the flow of electric currents through electrocatalysts, while DFT-based approaches are for equilibrium states that exclude electric current from calculations. In this work, based on the steady-state density functional theory (SS-DFT) that considers nonequilibrium effects using Hershfield quantum statistics, we propose a nonequilibrium ab initio approach to model electrocatalysis. The approach is applied to investigate the electrocatalytic properties of Au surfaces towards N2 reduction reaction (NRR) for the formation of NH3. Our calculations reveal potential-dependent nonequilibrium effects on N2 adsorption and NRR reaction mechanism on various Au surfaces, providing insights into experimentally observed intriguing but puzzling electrocatalytic activity of the Au(310) surface that conventional DFT calculations could not explain.