Recent Advances in Phosphorus-Coordinated Transition Metal Single-Atom Catalysts for Oxygen Reduction Reaction

Carbon-supported heteroatom-coordinated metal single-atom catalysts (SACs) are promising electrocatalysts for oxygen reduction reaction (ORR) due to their low cost and tunable catalytic activity. Adjusting the electronic structure of the active center is an effective way to improve the activity of SACs. Compared with the intensively studied nitrogen-coordinated transition metal atoms (e. g. Fe, Co and Mn), phosphorus-coordinated and nitrogen-phosphorus dual-coordinated ones exhibit different electronic structures, which changes the reaction energy barrier and enhances the catalytic activity. This review summarizes recent advances in phosphorus coordination SACs for ORR in terms of theoretical study, site structure determination, synthesis method and catalytic activity. Further research is called for to explore the precise synthesis of phosphorus coordination SACs in a controllable manner and check the SACs under actual working conditions.