Fabrication and performance evaluation of a novel membrane electrode assembly for DMFCs

Abstract

In the current study, a nano-scale perovskite LaNi_0.5Fe_0.5O₃ (LaNi_0.5Fe_0.5O₃NPs) was synthesized by a rapid ultrasonic-assisted co-precipitation method and characterized by various techniques. A modified glassy carbon electrode with Pd nanoparticles (PdNPs) and LaNi_0.5Fe_0.5O₃NPs dispersed into chitosan (CH) polymer was prepared and its catalytic activity toward methanol oxidation was investigated. Based on the electrochemical studies, the PdNPs-LaNi_0.5Fe_0.5O₃NPs-CH nanocomposite showed considerable activity for methanol oxidation in comparison to PdNPs-CH. Then a gas diffusion layer (GDL) was prepared with the ratio of 40% wt graphene carbon and 60% wt polymer mixture (consisting of 35% wt polyvinyl chloride and 65% wt polyaniline) for the micro-porous layer and a teflonated carbon cloth as the macro-porous substrate. A direct methanol fuel cell was designed, assembled and tested with the suggested PdNPs-LaNi_0.5Fe_0.5O₃NPs-CH nanocomposite as anodic catalyst and the synthetic GDL under several different conditions.