A multiscale fluid dynamics perspective on bubble management in water electrolysis

Water electrolysis for hydrogen production has traditionally focused on catalyst development and materials optimization, yet bubble dynamics—an inherent feature of gas-evolving reactions—represents a largely overlooked bottleneck that can account for significant efficiency losses. As electrochemical hydrogen production scales up to meet decarbonization goals, bubble-induced penalties, including increased ohmic resistance, blocked active sites, and mass transport limitations, have emerged as critical engineering challenges. This perspective examines bubble evolution in water electrolyzers through a fluid dynamics lens, bridging fundamental single-bubble physics with reactor-scale multiphase flows. We synthesize recent advances in nanobubble nucleation, detachment dynamics, and coalescence behavior, emphasizing how cross-disciplinary approaches and in operando characterization are revealing the complex forces governing bubble behavior at electrodes. Emerging strategies for bubble management are discussed, including pulsed electrolysis, artificial intelligence (AI)-assisted optimization, and novel reactor geometries. By connecting microscale bubble phenomena to macroscale electrolyzer performance, this perspective aims to guide the development of more efficient, fluid-engineered electrochemical systems.