A review of proton exchange membrane water electrolysis modeling: From micro-mechanisms to macro-systems

Proton exchange membrane water electrolysis (PEMWE) is crucial for global decarbonization but faces cross-scale bottlenecks, including high costs, complex mass transport, and dynamic degradation. This review synthesizes recent advances in PEMWE modeling, establishing a bottom-up framework spanning from micro-scale pore dynamics to macro-scale energy networks. At the micro-level, it highlights “ionomer-free” catalyst designs and transient gas-liquid two-phase flow mechanisms. At the cell and stack level, the discussion covers dynamic equivalent circuit models (ECM) and high-fidelity 3D multiphysics simulations for ultra-high-pressure operations. Finally, at the macro-system level, techno-economic analysis (TEA), cascaded waste heat recovery, and AI-driven autonomous management are explored. This review bridges materials science, fluid dynamics, and systems engineering to offer a theoretical roadmap for developing next-generation, highly efficient, and economically viable PEM electrolyzers.