Designing catalytic materials with enhanced stability and activity is crucial for sustainable electrochemical energy technologies. RuO₂ is the most active material for oxygen evolution reaction (OER) in electrolyzers aiming at producing ‘green’ hydrogen, however it encounters critical electrochemical oxidation and dissolution issues during reaction. It remains a grand challenge to achieve stable and active RuO₂ electrocatalyst as the current strategies usually enhance one of the two properties at the expense of the other. Here, we report breaking the stability and activity limits of RuO₂ in neutral and alkaline environments by constructing a RuO₂/CoOₓ interface. We demonstrate that RuO₂ can be greatly stabilized on the CoOₓ substrate to exceed the Pourbaix stability limit of bulk RuO₂. This is realized by the preferential oxidation of CoOₓ during OER and the electron gain of RuO₂ through the interface. Besides, a highly active Ru/Co dual-atom site can be generated around the RuO₂/CoOₓ interface to synergistically adsorb the oxygen intermediates, leading to a favourable reaction path. The as-designed RuO₂/CoOₓ catalyst provides an avenue to achieve stable and active materials for sustainable electrochemical energy technologies.

Kun Du, Lifu Zhang, Jieqiong Shan, Jiaxin Guo, Jing Mao, Chueh-Cheng Yang, Chia-Hsin Wang, Zhenpeng Hu, Tao Ling