Insight into the Mechanism of Dual-metal Atoms on N, S-codoped Graphene toward Oxygen Evolution Reactions: High Performance Inspired by Dual Active Sites.

The development of highly efficient and cost-effective catalysts to drive the oxygen evolution reaction (OER) is of significant importance for sustainable energy and energy conversion. However, the acceleration of the sluggish kinetics of the OER relies primarily on the use of noble metals at present. In this work, we proposed a series of single/dual metal atoms loaded on N, S-doped graphene and investigated the OER mechanism with dual metal and nonmetal active sites at the atomic level using density functional theory (DFT). The theoretical results reveal that dual active sites, including the doping of N, S and dual transition metals in catalysts (M1M2N8S-gra, M1= Co, Ni, Fe, M2= Co, Ni, Fe, Cu), can reduce the overpotential and thereby synergistically promote the catalytic efficiency in the OER process. Notably, CoCo and FeFe based dual atoms catalysts exhibit the lowest theoretical overpotential and the promising OER catalytic activity. The superior catalytic activity arises from the modulated charge transfer between the catalysts and the adsorbed intermediates, appropriate adsorption energies for adsorption and desorption and resulted reduced overpotential, and can be attributed to the dual active sites with the incorporation of S and the second metal atoms. Our study provides theoretical insights into the dual active site mechanisms for the OER at the atomic level, offering a new perspective for designing high performance OER catalysts.Graphical Abstract: The development of highly efficient and cost-effective catalysts to drive the oxygen evolution reaction (OER) is of significant importance for sustainable energy and energy conversion. However, the acceleration of the sluggish kinetics of the OER relies primarily on the use of noble metals at present. In this work, we proposed a series of single/dual metal atoms loaded on N, S-doped graphene and investigated the OER mechanism with dual metal and nonmetal active sites at the atomic level using density functional theory (DFT). The theoretical results reveal that dual active sites, including the doping of N, S and dual transition metals in catalysts (M1M2N8S-gra, M1= Co, Ni, Fe, M2= Co, Ni, Fe, Cu), can reduce the overpotential and thereby synergistically promote the catalytic efficiency in the OER process. Notably, CoCo and FeFe based dual atoms catalysts exhibit the lowest theoretical overpotential and the promising OER catalytic activity. The superior catalytic activity arises from the modulated charge transfer between the catalysts and the adsorbed intermediates, appropriate adsorption energies for adsorption and desorption and resulted reduced overpotential, and can be attributed to the dual active sites with the incorporation of S and the second metal atoms. Our study provides theoretical insights into the dual active site mechanisms for the OER at the atomic level, offering a new perspective for designing high performance OER catalysts. [ABSTRACT FROM AUTHOR]