Regulating d-orbital hybridization of subgroup-IVB single atoms for efficient oxygen reduction reaction.

Zhao, Xue; Sun, Yong; Wang, Jinming; Nie, Anmin; Zou, Guodong; Ren, Liqun; Wang, Jing; Wang, Yong; Fernandez, Carlos; Peng, Qiuming

Abstract

Highly active single-atom electrocatalysts for the oxygen reduction reaction are crucial for improving the energy conversion efficiency, but they suffer from a limited choice of metal centers and unsatisfactory stabilities. Here, this work reports that optimization of the binding energies for reaction intermediates by tuning the d-orbital hybridization with axial groups converts inactive subgroup-IVB (Ti, Zr, Hf) moieties (MN4) into active motifs (MN4O), as confirmed with theoretical calculations. The competition between metal-ligand covalency and metal-intermediate covalency affects the d-p orbital hybridization between the metal site and the intermediates, converting the metal centers into active sites. Subsequently, dispersed single-atom M sites coordinated by nitrogen/oxygen groups have been prepared on graphene (s-M-N/O-C) catalysts on a large-scale with high-energy milling and pyrolysis. Impressively, the s-Hf-N/O-C catalyst with 5.08wt% Hf exhibits a half-wave potential of 0.920V and encouraging performance in a zinc-air battery with an extraordinary cycling life of over 1600h and a large peak power-density of 256.9mW cm−2. This work provides promising single-atom electrocatalysts and principles for preparing other catalysts for the oxygen reduction reaction.

Citation

ZHAO, X., SUN, Y., WANG, J., NIE, A., ZOU, G., REN, L., WANG, J., WANG, Y., FERNANDEZ, C. and PENG, Q. 2024. Regulating d-orbital hybridization of subgroup-IVB single atoms for efficient oxygen reduction reaction. Advanced materials [online], Early View. Available from: https://doi.org/10.1002/adma.202312117

• Journal Article Type: Article
• Acceptance Date: Feb 20, 2024
• Online Publication Date: Feb 28, 2024
• Deposit Date: Mar 8, 2024
• Publicly Available Date: Mar 1, 2025
• Journal: Advanced materials
• Print ISSN: 0935-9648
• Electronic ISSN: 1521-4095
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1002/adma.202312117
• Keywords: Axial coordination; d-orbital hybridization; Mass production; Oxygen reduction reaction; Subgroup-IVB single atoms
• Public URL: https://rgu-repository.worktribe.com/output/2262191
• Additional Information: Supplementary materials are appended after the main text of this document.