A review on physical and chemical hydrogen storage methods for sustainable energy applications

A comprehensive review of physical, chemical, and geological hydrogen storage and delivery methods to support sustainable energy systems is presented a survey of compressed gas, liquid hydrogen, adsorption on porous carbon and metal organic frameworks, metal and complex hydrides, liquid organic hydrogen carriers, and subsurface options such as salt caverns and depleted reservoirs is provided. Pathways are compared using energy density, reversibility, efficiency, safety, scalability, and cost, and synthesize design trade-offs across mobile and stationary applications. Compressed gas demonstrates technological maturity yet faces compression energy penalties and lower volumetric density. Liquid hydrogen offers compact storage and long-distance transport but contends with liquefaction energy demand and boil-off losses. Metal and complex hydrides enable dense, inherently contained storage, with challenges in heat management and reaction kinetics. Adsorption materials show promise yet often require low temperature for high uptake. Liquid organic hydrogen carriers leverage familiar logistics at the expense of catalytic dehydrogenation steps and efficiency. Geological storage provides seasonal and strategic capacity, with salt caverns emerging as strong candidates while contamination and integrity risks require monitoring and robust standards. Highlight hybrid architectures that pair high-pressure tanks with hydride beds and advanced cryo-compressed approaches that increase practical capacity for mobility. Priorities include faster kinetics at moderate temperature, durable sorbents and hydrides, loss mitigation, standardized safety protocols, techno-economic benchmarks, and integration with renewable grids and transport.