Co–Fe alloy nanoparticles and Fe3C nanocrystals on N-doped biomass-derived porous carbon for superior electrocatalytic oxygen reduction

Abstract Nowadays, developing efficient and low-cost catalysts to catalyze oxygen reduction reaction (ORR) is important to alleviate environmental pollution and energy scarcity. Herein, we describe an ORR electrocatalyst that anchors Co–Fe alloy nanoparticles (NPs) on the carbon support obtained from biomass (Sichuan pepper powder), which can effectively convert O2 into water. The precursor containing cobalt phthalocyanine and Sichuan pepper powder is modified with nitrogen-rich ligand-pyrrole by using FeCl3 as the initiator, and then the nitrogen-rich Co–Fe-based biomass carbon catalyst is synthesized by highly efficient one-step pyrolysis at 900 °C (defined as FeCoNC-900). It was found that not only Co–Fe alloy nanoparticles were produced, but also graphene-packaged metallic Fe3C nanocrystals around Co–Fe alloy nanoparticles were formed during the pyrolysis. The results show that the best performing catalyst (FeCoNC-900) exhibits higher half-wave potential (0.91 V vs. reversible hydrogen electrode (RHE)) and better stability in an alkaline electrolyte in comparison with the 20 wt% Pt/C.