Potential Benefits, Challenges and Perspectives of Various Methods and Materials Used for Hydrogen Storage

Fossil fuels, which are extremely harmful to the environment and not renewable, predominantly serve the majority of the world's energy needs. Currently, hydrogen is regarded as the fuel of the future due to its many advantages, such as its high calorific values, high gravimetric energy density, eco-friendliness, and nonpolluting nature, as well as being a zero-emission energy source. For sustainable global growth, it is essential to produce and store hydrogen on a large scale by utilizing renewable energy sources. However, hydrogen storage systems, particularly for vehicle on-board applications, face challenges in terms of developing energy-efficient and affordable techniques and materials due to hydrogen's buoyancy, lightness, and high diffusivity. This Review systematically discusses various hydrogen storage methods and materials, including physical storage like compressed gas, physical adsorption storage like carbon-based materials, metal–organic frameworks (MOFs), and other porous materials, as well as chemical storage like ammonia, methanol, formic acid, liquid organic hydrogen carriers (LOHCs), metal hydrides, and two-dimensional MXene-based materials. The advantages of various storage mechanisms are thoroughly discussed, as well as any potential implementation difficulties for real-world uses and future prospects.