文献类型：期刊文献

英文题名：Geometry-regulated hydrogen bubble dynamics and voltage instability on microelectrodes during water electrolysis

作者：Wang, Yue[1]; Wu, Tao[1]; Dong, Lei[2]; Yuan, Fang[1]; Yang, Qiang[1]; Liu, Bo[1]

机构：[1] Department of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China; [2] Key Laboratory for Ultrafine Materials of Ministry of Education, School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China

年份：2026

外文期刊名：SSRN

收录：EI(收录号：20260370093)

语种：英文

外文关键词：Bubbles (in fluids) - Coalescence - Electrochemical electrodes - Electrolytes - Gas generators - Gases - Geometry - Hydrogen evolution reaction - Hydrogen production - Microelectrodes - Oscillating flow - Oscillators (mechanical) - Stability

摘要：Gas bubble evolution during water electrolysis governs bubble-mediated interfacial transport, active-site availability, and voltage stability in gas-evolving electrochemical systems. Although microelectrodes are widely used as model platforms for probing electrochemical bubble dynamics, how electrode geometry regulates bubble evolution and the resulting electrochemical instability remains insufficiently understood. Here, platinum microelectrodes with diameters of 100, 200, and 500 μm are employed as well-defined model electrodes to investigate hydrogen bubble dynamics during the hydrogen evolution reaction (HER) in acidic electrolyte under galvanostatic conditions. By combining electrochemical measurements with high-speed imaging, we show that individual bubble growth follows an apparent Faradaic gas-production-limited scaling,d_b(t)=βt^(1/3) , within the experimentally resolved growth window across all electrode sizes. In contrast, the bubble growth coefficient β, bubble lifetime, detachment diameter, coalescence behavior, and potential response exhibit strong geometry dependence. Larger electrodes provide broader active areas with more nucleation sites and frequent bubble coalescence, leading to higher apparent β values, shorter bubble lifetimes, smaller detachment diameters, and delayed onset of periodic voltage oscillations at a given current. Conversely, smaller electrodes confine gas generation into single-bubble-dominated regimes, resulting in larger detachment sizes and earlier periodic bubble-induced voltage oscillations. Notably, the critical current density required to trigger periodic oscillations scales linearly with electrode size, establishing a quantitative link between electrode geometry, bubble detachment dynamics, and electrochemical instability. These findings provide a quantitative basis for selecting electrode feature size and operating current-density windows to mitigate bubble-induced voltage instability in water electrolysis systems. ? 2026, The Authors. All rights reserved.