Integrating two-phase modeling and topology optimization for high-performance proton exchange membrane water electrolyzer electrodes

In proton exchange membrane water electrolyzers (PEMWEs), performance limitations and high catalyst costs are primarily associated with mass transport bottlenecks and suboptimal anode catalyst layer structures. This study presents a validated two-dimensional model that incorporates key mass transport and reaction phenomena, including oxygen evolution and two-phase flow dynamics, to investigate and optimize anode catalyst layer performance. Using topology optimization (TO) based on the density method, we identified electrode structures that significantly enhance electrochemical activity and catalyst utilization. The fully optimized catalyst layer design achieved up to a 65 % improvement in overall performance and a 58 % improvement in catalyst utilization, while a physically fabricated demonstration structure, inspired by the optimized design, achieved a 44 % improvement in catalyst utilization. Comparative analysis of simulated and experimental results highlighted improvements in mass transport, reactant distribution, and oxygen removal as the primary mechanisms underlying the performance gains. This work demonstrates the potential of to reduce catalyst usage while enhancing PEMWE efficiency and provides a practical framework for translating computationally optimized designs into manufacturable electrode structures, advancing the development of high-performance and cost-effective PEMWE systems.