Review on electrode materials for electrochemical hydrogen storage systems

Significant technological advancements have been made in the production and utilization of hydrogen (H2) since 1990, marking the period when its potential as a fuel began to be widely recognized. However, for a hydrogenbased energy system to be viable, especially in the transportation sector, substantial improvements in H2 storage technology are necessary. Various methods are available for supplying hydrogen to vehicles, including compressed or liquid hydrogen, metal hydrides, chemical storage, and gas adsorption on solid surfaces. Among these, gas-on-solid adsorption emerges as a highly efficient and safe method for storing hydrogen gas. This review briefly summarizes research on hydrogen adsorption using nanostructured adsorbents, such as carbon-based nanostructures (graphene, reduced graphene oxide, carbon nanotubes, carbon nitride, and other carbon nanostructures), metals and metal oxides, polymers, and metal-organic frameworks. Additionally, it covers new experimental and theoretical investigations into the hydrogen adsorption capabilities of metal hydrides.