A post-modification strategy to precisely construct dual-atom sites for oxygen reduction electrocatalysis

Dual-atom catalysts (DACs) afford promising potential for oxygen reduction electrocatalysis due to their high atomic efficiency and high intrinsic activity. However, precise construction of dual-atom sites remains a challenge. In this work, a post-modification strategy is proposed to precisely fabricate DACs for oxygen reduction electrocatalysis. Concretely, a secondary metal precursor is introduced to the primary single-atom sites to introduce direct metal–metal interaction, which ensures the formation of desired atom pair structure during the subsequent pyrolysis process and allows for successful construction of DACs. The as-prepared FeCo-NC DAC exhibits superior oxygen reduction electrocatalytic activity with a half-wave potential of 0.91 V vs. reversible hydrogen electrode. Zn–air batteries equipped with the FeCo-NC DAC demonstrate higher peak power density than those with the Pt/C benchmark. More importantly, this post-modification strategy is demonstrated universal to achieve a variety of dual-atom sites. This work presents an effective synthesis methodology for precise construction of catalytic materials and propels their applications in energy-related devices.