Investigation of MIL-53(Fe)-(COOH)2 as a Filler in Sulfonated Polystyrene/Polyethylene Membrane for Application in Direct Methanol Fuel Cell

Some of the main challenges of direct methanol fuel cell membranes are proton conduction and the high selectivity required. In the present study, new proton exchange membranes were developed using sulfonated polystyrene (SPS), polyethylene (PE), and a type of Metal-Organic Framework (MOF) used in the Direct Methanol Fuel Cells (DMFCs). MIL-53(Fe)-(COOH)2 is a metal-organic framework prepared in this study, and it was used as a filler in manufacturing the membranes. Characterization of these membranes was performed by SEM, FT-IR, and TGA. SEM images showed that the MIL-53(Fe)-(COOH)2 particles have a porous surface without any agglomeration. Also, the conductivity of proton, methanol permeability, oxidation resistance, and ion conductance tests were performed on membranes to evaluate membrane performance. The effect of MIL-53(Fe)-(COOH)2 content in membranes was also studied. The embedding of MIL-53(Fe)-(COOH)2 in SPS/PE membrane increases proton conductivity and selectivity factor. Finally, the prepared membranes were applied to the direct methanol fuel cell, and the performance of the membranes was examined. The result was a maximum peak power density of 23.61 mWcm2 with a maximum current density of 138.46 mA/cm2.