Experimental study of anode catalyst loading reduction in PEM fuel cells under high and low humidity conditions

The performance of a single proton exchange membrane fuel cells (PEMFCs) under relative humidity and anode catalyst loading variation was carried out in this study. Three membrane electrode assemblies (MEAs) with different anode catalyst loadings (0.5, 0.4, and 0.3 mgPt cm–²) were evaluated under fully humidified (100 % RH) and low-humidity (28 % RH) conditions. Voltage–current density, power density, and resistance–current density curves were analyzed. At 100 % RH, all MEAs showed stable resistive behavior and high-power output, with higher anode catalyst loading leading to improved voltage retention and maximum power density. In contrast, low-humidity operation caused marked performance losses, especially for MEAs with lower anode catalyst loading, as reflected by increased voltage losses, reduced maximum current density, and lower power density. Resistance results indicate that membrane hydration governs resistive losses, while higher anode catalyst loading improves performance robustness under reduced-humidity conditions. These findings emphasize the combined role of humidity management and anode catalyst loading for stable PEMFC operation.