Tantalum-stabilized ruthenium oxide electrocatalysts for industrial water electrolysis
Jiahao Zhang, Xianbiao Fu, Soonho Kwon, Kaifeng Chen, Xiaozhi Liu, Jin Yang, Haoran Sun, Y. W. Wang, Tomoki Uchiyama, Yoshiharu Uchimoto, Shaofeng Li, Yan Li, Xiaolong Fan, Gong Chen, Fanjie Xia, Jinsong Wu, Yanbo Li, Qin Yue, Liang Qiao, Dong Su, Hua Zhou, William A. Goddard, Yijin Kang
Abstract
The iridium oxide (IrO 2 ) catalyst for the oxygen evolution reaction used industrially (in proton exchange membrane water electrolyzers) is scarce and costly. Although ruthenium oxide (RuO 2 ) is a promising alternative, its poor stability has hindered practical application. We used well-defined extended surface models to identify that RuO 2 undergoes structure-dependent corrosion that causes Ru dissolution. Tantalum (Ta) doping effectively stabilized RuO 2 against such corrosion and enhanced the intrinsic activity of RuO 2 . In an industrial demonstration, Ta-RuO 2 electrocatalyst exhibited stability near that of IrO 2 and had a performance decay rate of ~14 microvolts per hour in a 2800-hour test. At current densities of 1 ampere per square centimeter, it had an overpotential 330 millivolts less than that of IrO 2 .