文献类型：期刊文献

英文题名：Coalescence-induced late departure of bubbles improves water electrolysis efficiency

作者：Wu, Tao[1];Liu, Bo[1];Hao, Haohao[2];Yuan, Fang[1];Zhang, Yu[1];Tan, Huanshu[2];Yang, Qiang[1]

机构：[1]East China Univ Sci & Technol, Dept Mech & Power Engn, Shanghai 200237, Peoples R China;[2]Southern Univ Sci & Technol, Ctr Complex Flows & Soft Matter Res, Dept Mech & Aerosp Engn, Multicomponent Fluids Grp, Shenzhen 518055, Guangdong, Peoples R China

年份：2026

卷号：6

期号：4

外文期刊名：ESCIENCE

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001775876500001)】；

基金：This work was financially supported by the National Natural Science Foundation of China (Grant Nos. 52025103, 22178099, 12472271) , the Shanghai Pilot Program for Basic Research (Grant. No. 22TQ1400100-11) , the Special Project for Peak Carbon Dioxide Emissions-Carbon Neutrality (Grant No. 21DZ1207800) from the Shanghai Municipal Science and Technology Commission, and the Guangdong Basic and Applied Basic Research Foundation (Grant Nos. 2024A1515010509, 2024A1515010614) .

语种：英文

外文关键词：Water electrolysis; Bubble coalescence; Electrolysis efficiency; Gas-evolving electrodes; Interfacial mass transport

摘要：In water electrolysis, smaller bubble departure sizes are traditionally considered beneficial for electrolysis efficiency. However, we show that this paradigm breaks down at high current densities, where bubble coalescence fundamentally reshapes departure dynamics. By tuning coalescence via electrolyte composition, we find that coalescence-prone systems-despite forming larger bubbles-achieve up to 30% higher HER efficiency than coalescence-inhibited ones in both acidic and alkaline media. Experiments and simulations reveal a coalescenceinduced delayed departure mechanism, where just-detached bubbles linger near the electrode and continuously merge with surface-anchored microbubbles. This coalescence delays the just-detached bubble from departing and allows it to grow further. Simultaneously, it promotes early anchored-microbubble removal (< 10 mu m), frees active sites, and induces intense local mixing (> 1 m/s), enhancing interfacial mass and heat transport. This efficiency gain is suppressed when coalescence is inhibited, but it can be restored by promoting bubble coalescence. These findings challenge the long-standing assumption that smaller bubbles always yield higher efficiency, and establish coalescence promotion as a broadly applicable strategy for improving performance, particularly in intrinsically coalescence-inhibited systems such as alkaline/seawater electrolysis and chlor-alkali processes.