Membrane-based separation technology in the hydrogen value chain: from material innovations to process strategies

Hydrogen is expected to play a crucial role in the transition to a low‑carbon energy system, in which membrane-based technologies are critical for its efficient production, distribution, and utilization. From a materials-focused perspective, this review examines a broad range of hydrogen-selective membranes, including palladium alloys, zeolites, carbon molecular sieves, metal–organic frameworks and covalent–organic frameworks, two‑dimensional membranes, polymeric films, and mixed‑matrix membranes. We systematically summarize their performance in terms of permeability, selectivity, and chemical and mechanical stability, and compare the current state-of-the-art benchmarks. General synthesis strategies, key material modifications, and their effects on gas transport properties and operational robustness under realistic conditions are thoroughly discussed. Additionally, we address critical challenges related to scale-up, long-term durability, and compatibility with diverse hydrogen production technologies. To bridge the gap between laboratory development and industrial application, material design must be aligned with scalable fabrication, standardized performance evaluation, and system-level integration. By emphasizing both material innovation and practical implementation, this review outlines how efficient membrane technologies can realize a sustainable, low-carbon hydrogen economy.