Proton conduction promoted by 1H-1,2,3-benzotriazole in non-humidified polymer membranes

Heterocyclic protogenic solvents are promising candidates in production of proton conductive non-humidified membranes. In this work, 1H-1,2,3-Benzotriazole, BTri which is a novel protogenic solvent was incorporated into Nafion and polyvinylphosphonic acid, PVPA to produce novel anhydrous membranes. The composite membranes were characterized using FTIR, TGA and DSC. TGA results confirmed the thermal stability of the membranes and DSC results verified the homogeneity of the materials. The proton conductivity of these polymer electrolyte membranes with respect to BTri content was investigated. 1H-1,2,3-Benzotriazole promoted the proton conductivity of the membranes reaching approximately 10−3 S/cm at 150 °C, under anhydrous conditions. Cyclic voltammetry (CV) results demonstrated that 1H-1,2,3-benzotriazole has broad electrochemical stability domain.

► Benzotriazole is a novel heterocycle that provides high proton conductivity in acidic polymers.
► Polyvinyl phosphonic acid and Nafion were blended with 1H-1,2,3-benzotriazole.
► In anhydrous state, maximum proton conductivity was obtained for NBTri1.5 membrane as 0.002 S/cm.