Engineering the Local Atomic Environments of Indium Single-Atom Catalysts for Efficient Electrochemical Production of Hydrogen Peroxide

Abstract

The in-depth understanding of local atomic environment-property relationships of p-block metal single-atom catalysts toward the 2 e^- oxygen reduction reaction (ORR) has rarely been reported. Here, guided by first-principles calculations, we develop a heteroatom-modified In-based metal-organic framework-assisted approach to accurately synthesize an optimal catalyst, in which single In atoms are anchored by combined N,S-dual first coordination and B second coordination supported by the hollow carbon rods (In SAs/NSBC). The In SAs/NSBC catalyst exhibits a high H₂ O₂ selectivity of above 95 % in a wide range of pH. Furthermore, the In SAs/NSBC-modified natural air diffusion electrode exhibits an unprecedented production rate of 6.49 mol peroxide g_catalyst ^-1 h^-1 in 0.1 M KOH electrolyte and 6.71 mol peroxide g_catalyst ^-1 h^-1 in 0.1 M PBS electrolyte. This strategy enables the design of next-generation high-performance single-atom materials, and provides practical guidance for H₂ O₂ electrosynthesis.

Keywords: Electrocatalysis; Hydrogen Peroxide; Indium Single-Atom Catalyst; Local Coordination Environments; Metal-Organic Frameworks.