Optimizing design of catalyst layer structure with carbon-supported platinum weight ratio mixing method for proton exchange membrane fuel cells

Abstract

The design of catalyst structure of proton exchange membrane fuel cells (PEMFCs) functions a crucial role in water and reactants transport. In this work, catalyst layer is designed to mixing strategy of commercial Pt/C catalysts with various weight ratios (20 wt%, 40 wt%, and 20 + 40 wt%). Our mixing strategy demonstrates beneficial effects for optimized catalyst structure, leading to improved electrochemical performance and durability. Mix weight ratio Pt/C (as we abbreviated 20 + 40 wt% to Mix wt%) confirmed the optimized morphology through physical characterization and verified through electrochemical characterization under varying relative humidity (RH) conditions. Remarkably, Mix wt% Pt/C showed the highest electrochemical performance at 40-120 % RH, with a maximum power density elevation of -42 % and charge transfer resistance improvement of -40 % under low humidity conditions. This enhancement can be attributed to the improved mass transport resulting from increased pore size and reduced distortion in transport pathways. Additionally, we performed a 5,000 cycle accelerated stress test (AST), demonstrating enhanced durability in Mix wt% Pt/C. Our strategy provides a reproducible and simplified process to achieve higher fuel efficiency. Moreover, we anticipate that this offers the potential to enhance both performance and durability in commercial PEMFC applications.