Recent advances in hydrogen storage using catalytically and chemically modified graphene nanocomposites

Abstract

The need for efficient and renewable energy fuels is growing stronger with environmental consciousness, stringent emission norms, rising fossil fuel prices and their depleting stocks. Hydrogen could be a significant replacement for fossil fuels if targets of volumetric and gravimetric densities required for the automobile industry can be met. In this regard, hydrogen economy and hydrogen storage have become thrust areas of research in the past few decades. It is possible to store hydrogen in the solid state as chemically bound hydrogen using metal/alloy nanostructures with favorable adsorption sites. These nanoparticles when dispersed over suitable carbon nanomaterials exhibit better storage capabilities and improved adsorption–desorption kinetics. High surface area carbon supports such as graphene favor good dispersion of catalyst nanoparticles alleviating their agglomeration and modulating the interaction strength between hydrogen atoms and metal nanoparticles by providing pathways for chemi–physisorption of hydrogen in these nanocomposites. In this review, the contribution of chemically modified graphene-based materials and their composites with metal/alloy catalyst nanostructures in the field of hydrogen storage is reviewed and its future outlook discussed.