Enhancing the Catalytic Kinetics and Stability of Ru Sites for Acidic Water Oxidation by Forming Bronsted Acid Sites in Tungsten Oxide Matrix

作者：Wang, Xuefeng; Jang, Haeseong; Liu, Shangguo; Li, Zijian^*; Zhao, Xuhao; Chen, Yunfei; Kim, Min Gyu; Qin, Qing^*; Liu, Xien^*

来源：Advanced Energy Materials, 2023, 13(36).

DOI：10.1002/aenm.202301673

• acidic oxygen evolution reaction
• Bronsted acid sites
• durability
• oxidation resistance
• reaction kinetics

The oxygen evolution reaction (OER) suffers from sluggish kinetics even on the benchmark RuO2 catalyst, due to the complex four sequential proton-coupled electron transfer steps. Severe electrochemical oxidation and dissolution issues also make RuO2 fail as an alternative to highly expensive iridium-based OER catalysts applied in proton exchange membrane water electrolysis. Herein, an acid-stable W18O49-& delta; matrix-confined Ru solid solution oxide is developed with considerably reduced Ru loadings beyond commercial RuO2, to enhance the acidic OER kinetics and extend the long-term durability simultaneously by incorporating Bronsted acid sites. The representative Ru0.6W17.4O49-& delta; with 3D urchin-like morphology achieves an excellent catalytic stability with ultra-slow degradation rate and a high mass activity of 27 110 A g(Ru)(-1) @ 1.53 V versus RHE in 0.1 m HClO4 electrolyte, which is & AP;10.8 times higher than that of commercial RuO2. The enhanced electron transfer from W to Ru during the OER process prevents the over-oxidation of surface Ru sites extending the long-term stability, while the incorporated Ru-O-bri-W Bronsted acid sites accelerate the deprotonation step by promoting the mobility of proton from the oxo-intermediate to the neighboring O-bri sites, thus boosting the acidic OER kinetics.