Graphene Modified Fluorinated Cation-Exchange Membranes for Proton Exchange Membrane Water Electrolysis

Abstract

One of major current technical challenges in proton exchange membrane water electrolysis (PEMWE) is the limited proton conductivity. Nowadays, graphene is considered one of the most promising candidates for improving the ionic transport properties, isotopic selectivity and proton conductivity throughout the unique two-dimensional structure. In this paper, we report on the development of graphene modified commercial membranes (Fumapem®) containing different graphene loadings for PEMWE applications. The membranes are characterized by Scanning Electron Microscopy (SEM) and thermo-gravimetrical and differential thermal analysis (TGA-DSC). Properties of composite membranes are investigated, including water uptake and ion-exchange capacity (IEC). In plane four-electrode arrangement is used to determine the proton conductivity of the composite membranes. It is found that composite membranes show an improved behaviour when compared to pristine commercial membranes and graphene loading can improve proton conductivity. In our conditions, the calculated activation energy (Ea) for proton conduction is found to be about 3.80 kJ mol−1 for the composite Fumapem®/graphene membrane with 10 mg graphene loading, lower than of the pristine polymer proton exchange membrane.