Asymmetric S Heteroatom Coordinated Dual‐Atom Catalysts and Coupled Anodic Sulfion Oxidation to Boost Electrocatalysis Oxygen Reduction

Abstract

Considering the exceptional electronic regulation capability, p‐block elements can be used to regulate the charge density of traditional transition metal catalysts. In this work, CoGa‐NS‐C dual‐atom catalysts (DACs) are successfully synthesized through co‐precipitation and post‐annealing treatment. The atomic dispersion of Co and Ga and the synergistic coordination structure of CoN₃S₁ and GaN₄ are confirmed by AC‐TEM, EXAFS, and XPS. Due to the steric hindrance effect of adsorbed ^*OH on the Ga site and the asymmetric S heteroatom coordination on Co species, the adsorption energy of ^*OOH intermediation on neighboring Co is thus enhanced greatly, resulting in the enhancement of the 2e‐ORR pathway. Besides, ^*OOH and Co─OH intermediates are detected by in situ FT‐IR and EC‐SHINERS spectroscopy. A high H₂O₂ selectivity of 90.3% and a fast H₂O₂ production rate of 1.12 mol h⁻¹ g⁻¹ can be reached. In addition, the cathodic oxygen reduction is used to couple with sulfion oxidation reaction (SOR) instead of the energy‐intensive OER reaction. In this coupling system, the SOR potential is 1.31 V lower than the OER process at the current intensity of 100 mA. Both the proposed dual‐atom DACs regulation strategy by p‐block elements and the ORR‐SOR coupling system are beneficial for achieving efficient and energy‐effective 2e‐ORR.