Modulating the covalency of Ru-O bonds by dynamic reconstruction for efficient acidic oxygen evolution
Luqi Wang, Sung‐Fu Hung, Sheng Zhao, Yue Wang, Shengli Bi, Shaoxiong Li, Jianjie Ma, Chenchen Zhang, Ying Zhang, Linlin Li, Tsung‐Yi Chen, Han‐Yi Chen, Feng Hu, Yuping Wu, Shiling Peng
Abstract
Developing ruthenium-based oxide catalysts capable of suppressing lattice oxygen participation in the catalytic reaction process is crucial for maintaining stable oxygen evolution reaction (OER) under acidic conditions. Herein, we delicately construct a RuO2 nanoparticle-anchored LiCoO2 nanosheet electrocatalyst (RuO2/LiCoO2), achieving dynamic optimization of RuO2 during the reaction process and improving catalytic stability. Benefiting from the unique electrochemical delithiation characteristics of the LiCoO2 support, the covalency of the Ru-O bond is effectively regulated during the OER process. The weakened Ru-O covalent bond inhibits the participation of lattice oxygen in the catalytic reaction and ensures the continuous operation of the Ru active sites. Moreover, the extended Ru-O bond in the optimized RuO2/LiCoO2 catalyst reduces the formation energy barrier of the *OOH intermediates, accelerating the progress of the OER. As a result, the RuO2/LiCoO2 catalyst requires only an overpotential of 150 ± 2 mV at 10 mA cm−2 in 0.5 M H2SO4 and operates stably for 2000 h at 1 A cm−2 in a proton exchange membrane water electrolysis. This work opens new avenues for designing efficient ruthenium-based catalysts. Long-term stability is a key challenge for ruthenium-based oxygen evolution reaction (OER) catalysts. Here, the authors present a RuO2/LiCoO2 catalyst with dynamic Li dissolution, which weakens the covalency of the Ru-O bond to prevent the lattice oxygen mechanism, thereby ensuring stable acidic OER.