Cascade Hydrogen Peroxide Reduction Reaction Endows Cu-Fe Dual-Atom Catalyst with Durable Oxygen Reduction Performance

Abstract

Durable problems caused by the attack from free radicals are considered as the Achilles’ heel in practical applications for oxygen reduction reaction (ORR) in acidic conditions. Herein, a ligand-bridging strategy is proposed to design a Cu─Fe dual-atom catalyst (CuFeDAC-NC) to relieve the undesirable degradation caused by free radicals. Comprehensive investigations and theoretical calculations verify that the byproduct of hydrogen peroxide can be effectively eliminated at neighboring Cu sites through a cascade catalytic process, the formation of oxidative free radicals is suppressed, leading to enhanced durability. Meanwhile, the synergistic effect between the Cu site and Fe site results in superior ORR performance. CuFeDAC-NC catalyst delivers a half-wave potential (E1/2) of 0.811 V in 0.1 M HClO4 electrolyte and exhibits excellent durability with a small E1/2 loss of 12 mV after 10 000 potential cycles superior to that of Fe─NC (34 mV). This work not only provides a new perspective to get insight into the mechanisms of durability but also opens an avenue to design catalysts with enhanced durability.