Unraveling oxygen vacancy site mechanism of Rh-doped RuO2 catalyst for long-lasting acidic water oxidation

• Published in: Nature communications 2023-03, Vol.14 (1), p.1412-1412, Article 1412
• Main Authors: Wang, Yi, Yang, Rong, Ding, Yajun, Zhang, Bo, Li, Hao, Bai, Bing, Li, Mingrun, Cui, Yi, Xiao, Jianping, Wu, Zhong-Shuai
• Format: Article
• Language: English
• Subjects: 119/118; 140/133; 140/146; 140/58; 147/135; 147/137; 147/143; 147/3; 639/301/299/886; 639/4077/909/4086; 639/638/161/886; Acidic oxides; Acidic water; Adsorption; Catalysis; Catalysts; Durability; Electrocatalysts; Electrolytes; Evolution; Graphene; Humanities and Social Sciences; Hydrogen production; Ion exchange; Laboratories; Lattice vacancies; Microscopy; multidisciplinary; Oxidation; Oxygen; Oxygen evolution reactions; Rhodium; Ruthenium; Ruthenium oxide; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-37008-8

Exploring durable electrocatalysts with high activity for oxygen evolution reaction (OER) in acidic media is of paramount importance for H 2 production via polymer electrolyte membrane electrolyzers, yet it remains urgently challenging. Herein, we report a synergistic strategy of Rh doping and surface oxygen vacancies to precisely regulate unconventional OER reaction path via the Ru–O–Rh active sites of Rh-RuO 2 , simultaneously boosting intrinsic activity and stability. The stabilized low-valent catalyst exhibits a remarkable performance, with an overpotential of 161 mV at 10 mA cm −2 and activity retention of 99.2% exceeding 700 h at 50 mA cm −2 . Quasi in situ/operando characterizations demonstrate the recurrence of reversible oxygen species under working potentials for enhanced activity and durability. It is theoretically revealed that Rh-RuO 2 passes through a more optimal reaction path of lattice oxygen mediated mechanism-oxygen vacancy site mechanism induced by the synergistic interaction of defects and Ru–O–Rh active sites with the rate-determining step of *O formation, breaking the barrier limitation (*OOH) of the traditional adsorption evolution mechanism. Exploring highly active and durable Ru-based electrocatalysts for acidic water oxidation is challenging. Here authors reported an ion-exchange adsorption strategy to regulate oxygen vacancies and Rh dopant, with a corresponding fundamental investigation on the lattice oxygen oxidation and the oxygen vacancy site.