Breaking the Activity‐Stability Trade‐Off of RuO <sub>2</sub> via Metallic Ru Bilateral Regulation for Acidic Oxygen Evolution Reaction
Qian Lü, Jinjie Liu, Xiaohong Zou, Birou Huang, Weixing Wu, Jun Yin, Zhao‐Qing Liu, Ying Wang
Abstract
Abstract Developing highly efficient acidic oxygen evolution reaction (OER) electrocatalysts is crucial for proton exchange membrane water electrolyzer. RuO 2 electrocatalysts, which followed a kinetically favorable lattice oxygen mechanism, perform a preferable intrinsic activity, but poor stability for acidic OER. Recent work often sacrifices the intrinsic activity of RuO 2 to enhance stability. The balance between the activity and stability of RuO 2 ‐based catalysts is still overlooked in current research. Here, we report a controlled method to introduce metallic Ru onto RuO 2 catalysts to form the Ru 4+ ─O─Ru 0 interfacial structure for decreasing the Ru 4+ oxidation state and promoting deprotonation kinetics. Metallic Ru can serve as the electron donor to lower the oxidation state of *V o ‐RuO 4 2− in Ru/RuO 2 for stabilizing the structure of *V o ‐RuO 4 2− ‐Ru/RuO 2 to favour the acidic OER stability. Moreover, the deprotonation kinetics via the interfacial oxygen site between Ru 4+ and Ru 0 is significantly enhanced on Ru/RuO 2 catalysts to improve the acidic OER activity. This work offers a unique perspective to balance the acidic OER activity and stability of RuO 2 .