Membrane-Shaped MOF Proton Conductors

The escalating global energy demand has spurred intensive research into alternative energy technologies, among which proton-exchange membrane fuel cells (PEMFCs) stand out for their high efficiency and environmental benignity. However, conventional proton conductors like Nafion® face critical limitations, including water-dependent conductivity, high production costs, and poor performance under high-temperature/low-humidity conditions. Metal-organic frameworks (MOFs), with their tunable structures, high porosity, and diverse functionalization, have emerged as promising candidates to overcome these challenges. This review systematically summarizes the recent progress in membrane-shaped MOF proton conductors, focusing on three mainstream fabrication strategies: MOF-polymer blend membranes, MOF glass membranes, and substrate-deposited MOF films. The proton conduction mechanisms, structural design principles, and performance optimization strategies for each type are discussed. Additionally, the current challenges and future perspectives in advancing MOF-based membranes for practical PEMFC applications are highlighted.