The Correlation of Palladium Supported Carbon (Pd/C) Loading and Optimum Nafion Ionomer Weight Percent (wt.%) Content in the PEM Fuel Cell Catalyst Layer

Abstract

The presence of Nafion ionomer as one of basic elements in the PEM fuel cell catalyst layer structure can extend the three phase contact between the reactant gases, electrolyte and the catalyst surface and make the catalyst layer active in three dimensions, since the proton can move throughout the entire catalyst layer, which would improve the PEM fuel cell performance. The main objective of this study is to examine the dependence of the optimum Nafion ionomer weight percent (wt.%), on the palladium supported carbon (Pd/C) loading in PEM fuel cell catalyst layer. The results showed that the optimum Nafion ionomer contents in the PEM fuel cell catalyst layer is dependent and inversely proportional to the amount of Pd/C loading. For catalyst layers with a Palladium supported carbon (Pd/C) loading of 4.0 ± 0.1 mg/cm2, 3.2 ± 0.1 mg/cm2, and 2.45 ± 0.05 mg/cm2, the best performance was obtained at about 33, 35, and 37 wt.% Nafion ionomer loading respectively.