Enhanced Performance of MIL-۱۰۰(Cr)-COOHIncorporated Sulfonated Polystyrene@Polyethylene Membranes for Direct Methanol Fuel Cells

The increasing demand for clean, efficient, and economically viable energy technologies has intensified research on high-performance proton exchange membranes for fuel cell systems. In this study, advanced SPS@PE composite membranes were fabricated by incorporating MIL-۱۰۰(Cr)-COOH nanofillers at varying concentrations (۵, ۱۰, and ۱۵ wt%). Unlike previously reported fillers such as MIL-۵۳(Fe)-(COOH)₂, MIL-۱۰۰(Cr)-COOH provides a significantly higher BET surface area, larger mesoporous cages, and a greater density of accessible –COOH groups, enabling improved water retention and the formation of extended hydrogen-bonding networks within the polymer matrix. These structural advantages contribute to enhanced proton transport efficiency and a more favorable conductivity–permeability balance. Comprehensive characterization using FTIR, SEM, and BET confirmed strong interfacial interactions between the MOF particles and the SPS@PE matrix, resulting in improved mechanical integrity, thermal stability, and controlled membrane swelling. Electrochemical measurements revealed that the membrane containing ۱۰ wt% filler (MM-۱۰) offered the best overall performance, achieving a proton conductivity of ۰.۰۹۶۳ S·cm⁻¹ at ۸۰ °C and ۶۰% relative humidity—values surpassing those reported for many previously published SPS- and MOF-based membranes. Moreover, single-cell DMFC tests demonstrated a maximum power density of ۸۷ mW·cm⁻², confirming the excellent catalytic and transport properties of the optimized composite. These findings demonstrate that MIL-۱۰۰(Cr)-COOH is a highly effective functional filler that significantly enhances the durability, proton selectivity, and operational performance of SPS-based membranes, making them strong candidates for next-generation direct methanol fuel cell applications.

کلیدواژه ها:

Direct Methanol Fuel Cells (DMFCs) ، Sulfonated Polystyrene (SPS) ، Metal-Organic frameworks (MOFs) ، MIL-۱۰۰(Cr)-COOH ، Proton Conductivity ، Methanol Permeability