Drastic improvement of electrical properties of Nafion® 112 membrane on impregnation of bimetallic Au/Pd nanoclusters

We report on the improvement in electrical conductivity of Nafion® 112 membrane by the impregnation of bimetallic Au/Pd nanometric clusters. Colloidal Au/Pd nanoclusters of different molar ratios were prepared by simultaneous reduction of corresponding metal salts. The colloidal bimetallic clusters were characterized by TEM and optical spectroscopy techniques. The Au/Pd nanoclusters of different molar ratios were impregnated into the well hydrated Nafion® membranes for 3 hrs. Optical absorption spectroscopy was used to verify the impregnation process. The electrical characteristics of the impregnated membranes were investigated by electrochemical impedance spectroscopy (EIS). The experiments were performed in a solid state electrochemical cell consisted of the impregnated Nafion® in electrical contact with Au electrodes. The EIS response of the impregnated membranes showed a drastic improvement in their electrical conductivity, which promises a better performance for the proton exchange membrane fuel cell (PEMFC) when Au/Pd nanocluster impregnated Nafion® is used as solid electrolyte.