Neighboring Fe-Cr electronic coupling simultaneously promotes intrinsic activity and suppresses Fe-induced degradation for oxygen reduction electrocatalysis

Abstract

Fe-N-C catalysts are among the most promising platinum-group-metal-free electrocatalysts for the oxygen reduction reaction (ORR), yet their practical application is limited by the insufficient intrinsic activity of isolated Fe sites and Fe-induced degradation. Herein, a neighboring Fe-Cr dual-atom catalyst (FeCr/N-P-C) is constructed via a one-step pyrolysis strategy. Structural characterizations reveal atomically dispersed neighboring Fe-Cr dual sites with a proposed axial N-Fe 1 N 3 -Cr 1 N 3 coordination configuration and strong interatomic electronic coupling. Benefiting from Cr-induced electronic modulation, the Fe sites exhibit a 4.6-fold higher turnover frequency (0.534 s − 1 at 0.80 V) than Fe single atoms, together with an onset potential of 1.01 V. The catalyst also shows an ultralow half-wave potential loss of only 21 mV after 30,000 cycles and retains 85% of its initial current after 8 h. In situ ATR-SEIRAS and mechanistic studies reveal accelerated *OOH conversion and suppressed ROS generation, accounting for the simultaneously enhanced ORR activity and durability. A rechargeable zinc-air battery delivers a peak power density of 187 mW cm − 2 and operates stably for over 150 h. This work demonstrates that neighboring dual-atom electronic coupling can simultaneously promote the intrinsic activity and durability of Fe single-atom catalysts, providing a general strategy for designing efficient and durable ORR electrocatalysts.