Atomic CoN₃S₁ sites for boosting oxygen reduction reaction via an atomic exchange strategy

It is vitally important to develop high-efficiency low-cost catalysts to boost oxygen reduction reaction (ORR) for renewable energy conversion. Herein, an A-CoN₃S₁@C electrocatalyst with atomic CoN₃S₁ active sites loaded on N, S-codoped porous carbon was produced by an atomic exchange strategy. The constructed A-CoN₃S₁@C electrocatalyst exhibits an unexpected half-wave potential (0.901 V vs. reversible hydrogen electrode) with excellent durability for ORR under alkaline conditions (0.1 M KOH), superior to the commercial platinum carbon (20 wt.% Pt/C). The outstanding performance of A-CoN₃S₁@C in ORR is due to the positive effect of S atoms doping on optimizing the electron structure of the atomic CoN₃S₁ active sites. Moreover, the rechargeable zinc-air battery in which both A-CoN₃S₁@C and IrO₂ were simultaneously served as cathode catalysts (A-CoN₃S₁@C &IrO ₂) exhibits higher energy efficiency, larger power density, as well as better stability, compared to the commercial Pt/C&IrO₂-based zinc-air battery. The present result should be helpful for developing lower cost and higher performance ORR catalysts which is expected to be used in practical applications in energy devices.