Hydrogen, a zero-emissions fuel, is increasingly being targeted as a source of renewable energy. However, hydrogen production by electrolysis is limited by the characteristics of the hydrogen-separating membrane. Here, a series of multiblock copolymers composed of a hydrophilic block based on disulfonated bis(phenyulfonylphenyl) sulfone groups, and a hydrophobic block based on bis(p-phenoxyphenyl) ether groups is developed for application as a proton exchange membrane for water electrolysis. The multiblock copolymers combining stiff hydrophilic block and flexible hydrophobic block are expected to have reduced water swelling and low hydrogen permeability even under full-wet and high-temperature conditions in water electrolysis. Microscopy and X-ray scattering analyses of the multiblock copolymer-based membranes reveal strong nanophase separation and well-developed ion transport channels. The as-synthesized membranes exhibit advantages including low swelling, high proton conductivity, good mechanical and thermal properties, high oxidative stability, and reduced hydrogen permeability. A membrane electrode assembly employing the multiblock copolymer membrane achieved a current density above 3 A cm⁻² at 1.8 V, far surpassing that of Nafion 212, and a long-term operating stability exceeding 500 h, demonstrating the suitability of the membrane for practical water electrolysis.

氢是一种零排放燃料，越来越多地成为可再生能源的目标。然而，电解制氢受到氢分离膜特性的限制。这里，一系列多嵌段共聚物由基于二磺化双（苯磺酰基苯基）磺基的亲水性嵌段和基于双（p）的疏水性嵌段组成。-苯氧基苯基）醚基团被开发用作水电解的质子交换膜。结合刚性亲水嵌段和柔性疏水嵌段的多嵌段共聚物预计即使在水电解的全湿和高温条件下也具有减少的水膨胀和低的氢渗透性。对基于多嵌段共聚物的膜的显微镜和 X 射线散射分析揭示了强大的纳米相分离和发达的离子传输通道。合成的膜具有低膨胀、高质子传导性、良好的机械和热性能、高氧化稳定性和降低的氢渗透性等优点。^{采用多嵌段共聚物膜的膜电极组件实现了3 A cm -2}以上的电流密度在1.8 V的电压下，远远超过Nafion 212，并且长期运行稳定性超过500 h，证明了该膜适用于实际水电解。