Atomically dispersed iron–zinc dual-metal sites to boost catalytic oxygen reduction activities for efficient zinc–air batteries

Abstract

Developing asymmetric heteronuclear dual-atom catalysts (DACs) through coordination microenvironment regulation and investigating their structure–activity relationship for the catalytic oxygen reduction reaction (ORR) are crucial for energy conversion and storage devices such as zinc–air batteries (ZABs). In this work, a novel catalyst with its Fe and Zn diatomic sites atomically dispersed on nitrogen-doped hierarchical porous carbon (FeZn–NC-800) was designed and synthesized under a cyanamide-assisted sintering atmosphere to stabilize Zn single atoms in the structure. Benefiting from specific synergy between the Fe and Zn atoms and the hierarchical porous carbon substrate, the obtained FeZn–NC-800 catalyst exhibits remarkable ORR performance with a positive half-wave potential of 0.89 V and good durability, outstripping the performance of most state-of-the-art catalysts and commercial precious metal catalysts. Moreover, the ZABs assembled with the FeZn–NC-800 cathodes exhibit an excellent peak power density of 218.6 mW cm⁻² and achieve stable cycling for over 200 hours at a current density of 10 mA cm⁻². This study provides a fresh new insight into the development of stable and highly active DAC materials, advancing the design of next-generation energy technologies.