Preparation of membrane-electrode assemblies for alkaline fuel cells: Effect of the ionomeric solution

•The concentration of ionomer affects both hydrogen oxidation and oxygen reduction reactions.•The catalytic activity is intrinsically related to the ionomer content in ionomeric solution.•The ORR and HOR exhibit 4e− and 2e− transfer, respectively, under different ionomer contents.•Ionomer content affects the structure and mechanical properties of the catalytic layer. The effect of the concentration of ionomeric solution on the anodic (hydrogen oxidation reaction, HOR) and cathodic (oxygen reduction reaction, ORR) reactions that take place at the anion exchange membrane fuel cell (AEMFC) was studied. The catalytic activity and the mechanism of the reactions were studied using commercial Pt/C catalyst in solutions with different ionomer content. The outcome in this study shows that kinetic and the mechanism of the reactions is affected by the loading of the conductive ionomer in catalyst layer, affecting the performance of the AEMFC, also changes are depicted in the structure and composition of the triple phase boundary.