Atomically dispersed trimetallic oxygen electrocatalysts for advancing rechargeable zinc-air battery

Developing efficient non-precious metal catalysts for oxygen electrocatalysis is crucial for advancing renewable energy storage systems like rechargeable Zn-air batteries. Nitrogen-doped carbon (M-N-C) materials with atomically dispersed metal sites, particularly Fe-N-C, exhibit remarkable activity for the oxygen reduction reaction (ORR); however, their performance in the oxygen evolution reaction (OER) remains unsatisfactory. In this work, we present the fabrication of Fe, Co, and Ni trimetallic SACs, which exhibit outstanding bifunctional catalytic performance. Using ZIF-8 and phytic acid as chelating agents, we achieved uniform dispersion of Fe, Co, and Ni atoms within a porous carbon matrix, preventing metal agglomeration and enhancing catalytic performance. The Fe₃₀Co₃₀Ni₃₀-PNC catalyst, after optimization, achieved a half-wave potential of 0.85 V for ORR and an OER overpotential of 310 mV at 10 mA cm⁻², outperforming many state-of-the-art non-precious metal catalysts. When applied in a Zn-air battery, it achieved a peak power density of 221 mW cm⁻², a specific capacity of 791.3 mAh gZn⁻¹, and remarkable durability over 330 hours. This study offers an efficient approach for developing high-performance catalysts for renewable energy applications.