Numerical Modeling and Topology Optimization for Designing the Anode Catalyst Layer in Proton Exchange Membrane Water Electrolyzers Considering Mass Transport Limitation

Abstract

With the escalation of global warming primarily attributed to fossil fuel and other non-renewable energy consumption, the production of green hydrogen emerges as a mitigation strategy to reduce fossil fuel usage and effectively harness renewable energy sources for energy storage. The proton exchange membrane water electrolyzer (PEMWE) stands out as a promising technology, boasting high efficiency and a rapid response to variations in current density. Despite its stellar performance, the reliance on precious materials presents a cost challenge. To address this concern, we developed a numerical model considering mass transport limitations and temperature variation. The topology optimization (TO) method is employed to generate the optimal structure of the electrode by organizing the two primary constituent materials. Additionally, the impact of optimization points representing low (1.73 V) and high (2.03 V) operating voltage characteristics is analyzed. The optimal structure demonstrates a maximum performance improvement of up to 2.7 times at an operating voltage of 2.03 V compared to the homogeneous electrode structure. The gas coverage model influences the rearrangement of constituent materials, particularly the void fraction, creating channels to facilitate the reaction. Optimization at high voltage points yields a more significant improvement compared to the low voltage scenario.