Liquid organic hydrogen carriers (LOHC): from definitions to recent developments

A potential solution to the drawbacks of compressed and liquefied hydrogen is the use of Liquid Organic Hydrogen Carriers (LOHCs), which provide safer, more scalable, and infrastructure-compatible storage. With a focus on reversible hydrogenation/dehydrogenation processes and their catalytic underpinnings, this review critically investigates LOHC technology. The transition from noble-metal to nickel-based catalysts is highlighted by recent developments, which enhance lifetime, selectivity, and activity in real-world scenarios. Comparative analysis of reactor concepts shows quantifiable improvements in scalability and efficiency, including membrane, hot-pressure swing, and reactive distillation systems. Integration with renewable energy and waste-heat utilization are reviewed, as are commercialization initiatives like pilot plants and hydrogen refueling stations. Reducing carrier costs, increasing catalyst durability, and lowering the energy demand for dehydrogenation are still ongoing challenges. This review establishes research priorities that will determine how LOHCs contribute to the development of a low-carbon, sustainable hydrogen economy by tying molecular design to system-level performance.