Inherent anti-Fenton property of single-atom rhenium for the ultra-durable oxygen reduction reaction

Abstract

It is of utmost urgency to construct M–N–C catalysts with inherent stability and high performances towards the oxygen reduction reaction (ORR). In principle, using the 4d and 5d transition metals (TM_4d,5d), particularly rhenium (Re), the desired M–N–C catalysts could be fabricated. However, it is a long-standing challenge to configure Re_5d single atom sites with ultra-durable ORR due to the occurrence of intractable Fenton reactions. In this contribution, we report a Re single-atom catalyst (Re-SAC) featuring a ReN₄ configuration that exhibits remarkable ORR activity and stability under alkaline conditions. Specifically, the half-wave potential (E_1/2) can reach a maximum of 0.89 V, and no significant changes in E_1/2 are observed after 10 000 cycles. The zinc–air battery demonstrates a superior open-circuit voltage of 1.55 V and exceptional durability, lasting over 300 h at 5 mA cm⁻². It was disclosed that incorporating Re into N–C structures effectively modulates the adsorption energy of ORR intermediates, thereby reducing the activation energy of the reaction. This work paves the way for designing high-performance single-atom catalysts based on TM_4d,5d centers for practical applications.