Revealing the importance of kinetics in N-coordinated dual-metal sites catalyzed oxygen reduction reaction

In this work, the oxygen reduction reaction (ORR) process on dual-metal-nitrogen-carbon (DM-N-C) catalysts by including two important factors (potential of zero charge and potential-dependent kinetics of O-O bond cleavage) from first-principle calculations is systematically investigated. Our results reveal that the origin for the high activity of dual-metal sites can be attributed to the fact that introducing a second metal site can facilitate the O-O bond cleavage in the key OOH* intermediate during ORR and meanwhile mitigate the *OH removal issue. Importantly, we define a descriptor called antibonding center that simplifies the evaluation of the kinetics. Based on the advanced approach used in this work, we demonstrate that several DM-N-C electrocatalysts including FeFeN6, FeCoN6, and CoZnN6 have high ORR activity consistent with previous experiments, and also predict MnCoN6 can be more highly stable and active for acidic ORR. This study demonstrates the advantage of the dual metal sites for the ORR in acidic electrolyte and highlights the significance of kinetics in the theoretical study of ORR electrocatalysts. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

By systematically investigating the oxygen reduction reaction process on dual-metal-nitrogen-carbon catalysts through first-principle calculations, it is found that the high activity of dual-metal sites can be attributed to facilitating O-O bond cleavage and mitigating *OH removal issue. The introduction of a descriptor called antibonding center simplifies the evaluation of kinetics.