Doping Shortens the Metal/Metal Distance and Promotes OH Coverage in Non-Noble Acidic Oxygen Evolution Reaction Catalysts

• Published in: Journal of the American Chemical Society 2023-04, Vol.145 (14), p.7829-7836
• Main Authors: Wang, Ning, Ou, Pengfei, Miao, Rui Kai, Chang, Yuxin, Wang, Ziyun, Hung, Sung-Fu, Abed, Jehad, Ozden, Adnan, Chen, Hsuan-Yu, Wu, Heng-Liang, Huang, Jianan Erick, Zhou, Daojin, Ni, Weiyan, Fan, Lizhou, Yan, Yu, Peng, Tao, Sinton, David, Liu, Yongchang, Liang, Hongyan, Sargent, Edward H.
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.2c12431

Acidic water electrolysis enables the production of hydrogen for use as a chemical and as a fuel. The acidic environment hinders water electrolysis on non-noble catalysts, a result of the sluggish kinetics associated with the adsorbate evolution mechanism, reliant as it is on four concerted proton-electron transfer steps. Enabling a faster mechanism with non-noble catalysts will help to further advance acidic water electrolysis. Here, we report evidence that doping Ba cations into a Co3O4 framework to form Co3–x Ba x O4 promotes the oxide path mechanism and simultaneously improves activity in acidic electrolytes. Co3–x Ba x O4 catalysts reported herein exhibit an overpotential of 278 mV at 10 mA/cm2 in 0.5 M H2SO4 electrolyte and are stable over 110 h of continuous water oxidation operation. We find that the incorporation of Ba cations shortens the Co–Co distance and promotes OH adsorption, findings we link to improved water oxidation in acidic electrolyte.