Preparation, characterization, and electrochemical properties investigation of recycled proton exchange membrane for fuel cell applications

The recycling of proton exchange membranes is very important based on both economic and environmental issues. In this study, recast Nafion membranes from commercial Nafion membrane and also used membrane electrode assemblies (MEAs) sources were prepared using different recycling techniques. The dissolution methods were performed in a high temperature and pressure reactor. At first, the three different dissolution methods were used to resolve the Nafion membranes and then the obtained solutions were cast. The prepared different recast Nafion membranes were evaluated by water uptake measurement, swelling behaviors, ion exchange capacity, proton conductivity at different temperatures, scanning electron microscopy, chemical and mechanical stability. The results showed the different recast Nafion membranes had appropriate water uptake, proton conductivity, chemical and mechanical stability level than commercial Nafion membrane. In the next step, the optimum method was chosen and used for recycling of the membrane of the well-worn membrane electrode assembly (MEA). The same characterization methods were used for characterization of recycled Nafion membrane. The physicochemical characterization results of recycled Nafion membrane showed promising characteristics. The comparison of results showed the recycled Nafion membrane from used MEA had the same characteristics as recast Nafion membrane.