Mesoporous Single-Crystalline Particles as Robust and Efficient Acidic Oxygen Evolution Catalysts
Yong Wang, Yunpu Qin, Sijia Liu, Yongzhi Zhao, Luan Liu, Di Zhang, Shangqing Zhao, Jianfang Liu, Jie Wang, Yadong Liu, Haoyang Wu, Baorui Jia, Xuanhui Qu, Hao Li, Mingli Qin
Abstract
High Resolution Image Download MS PowerPoint Slide The scarcity of iridium (Ir) limits its widespread use in acidic oxygen evolution reaction (OER). Herein, mesoporous single-crystalline spinel Co 3 O 4 with atomically dispersed low-valence-state Ir has been developed to enable Ir’s efficient and stable utilization. The surface Pourbaix diagram suggests that under acidic OER conditions, O* fully covers both Co 3 O 4 (111) and (110) surfaces, passivating Co sites but enhancing Co 3 O 4 ’s structural stability, a benefit further improved by Ir doping. Mesopores offer numerous loading sites for Ir single atoms (13.8 wt %), which activate the originally O*-passivated Co 3 O 4 (111) surface by creating high-intrinsic-activity Co–Ir bridge sites; meanwhile, Ir and Co leaching rates are reduced to about 1/4 and 1/5, respectively, compared to conventional Ir/Co 3 O 4 catalysts. Our catalyst exhibits a low η 10 of 248 mV for over 100 h, showcasing its potential in water electrolysis.