Accelerated Proton Transfer in Asymmetric Active Units for Sustainable Acidic Oxygen Evolution Reaction
Liming Deng, Sung‐Fu Hung, Shuyi Liu, Sheng Zhao, Zih‐Yi Lin, Chenchen Zhang, Ying Zhang, Ai‐Yin Wang, Han‐Yi Chen, Jian Peng, Rongpeng Ma, Lifang Jiao, Feng Hu, Linlin Li, Shengjie Peng
Abstract
The poor durability of Ru-based catalysts limits the practical application in proton exchange membrane water electrolysis (PEMWE). Here, we report that the asymmetric active units in Ru 1– x M x O 2 (M = Sb, In, and Sn) binary solid solution oxides are constructed by introducing acid-resistant p-block metal sites, breaking the activity and stability limitations of RuO 2 in acidic oxygen evolution reaction (OER). Constructing highly asymmetric Ru–O–Sb units with a strong electron delocalization effect significantly shortens the spatial distance between Ru and Sb sites, improving the bonding strength of the overall structure. The unique two-electron redox couples at Sb sites in asymmetric active units trigger additional chemical steps at different OER stages, facilitating continuous proton transfer. The optimized Ru 0.8 Sb 0.2 O 2 solid solution requires a superlow overpotential of 160 mV at 10 mA cm –2 and a record-breaking stability of 1100 h in an acidic electrolyte. Notably, the scale-prepared Ru 0.8 Sb 0.2 O 2 achieves efficient PEMWE performance under industrial conditions. General mechanism analysis shows that the enhanced proton transport in the asymmetric Ru–O–M unit provides a new working pathway for acidic OER, breaking the scaling relationship without sacrificing stability.