Unveiling activity of transition metal single-atom sites on the graphene-like BC2P monolayer for oxygen evolution reaction: A density functional theory study

Abstract

The electrocatalytic oxygen evolution reaction (OER) represents a pivotal process at the cathode of next-generation electrochemical storage and conversion technologies, among of them, OERs incorporating a single transition metal (TM) atom exhibit considerable potential for supplanting noble metals as electrochemical catalysts for fuel cells and metal-air batteries. Therefore, in this paper, we elucidated impacts of the TM monoatomic sites on the catalytic activity of OER on graphene-like BC2P monolayer through the utilization of density functional theory (DFT) calculations. Analysis of electronic structure reveals that the hybridised antibonding orbitals formed by the TM-3d and O-2p orbitals possess low-energy and high-occupancy properties, which weaken the OH-TM interactions and thus affect the catalytic activity of TM-N3 active site. Among all considered active sites, the Ni-N3 and Cu-N3 sites exhibited the most favourable OER catalytic performance, with the OER overpotential of the Ni-N3 site being only 0.42 eV, indicating an extremely high level of catalytic efficiency. Additionally, by exploring the coordination environment around the TM atoms, our study proposed a macroscopic descriptor and established a linear relationship between the catalytic performance and the descriptor using the linear regression. Therefore, our work offered theoretical guidance for the design of new and efficient OER catalysts, and further established a link between the microscopic mechanism of action and the macroscopic performance of catalysts, which providing new ideas for the development of high-performance catalytic materials.