Research Projects

Hydrogen energy is considered an efficient, clean, and eco-friendly alternative compared to fossil fuels. For practical usage, however, hydrogen must be stored at optimum conditions (temperatures and pressures) to ensure its easy reversibility and fast kinetics. There have been several attempts to utilize carbon-based materials and their analogues for hydrogen storage, but most of them have been found to weakly adsorb hydrogen. The next prominent candidates for hydrogen storage are metal decorated absorbents and complex metal hydrides. Note, however, that the cohesive energies of metal should be smaller than the adsorption energies. Transition metals are prone to cohesion because of their large cohesive energies. In order to avoid this, materials containing light elements should be preferred. For instance, the compounds or clusters containing s-block metals should be considered. As these metals possess relatively smaller cohesive energies, hydrogen is absorbed directly into the cluster and the problem of cohesion can be eliminated. However, the use of s-block metals is restricted by the fact that, unlike transition metals, they have fixed valence, i.e., oxidation state (+1). Therefore, their bonding tendency is very limited, which certainly affects the hydrogen storage capacity. Thus, there are several constraints, which need to be addressed for an efficient hydrogen storage system. This presumably requires a fundamental understanding of the systems being used for hydrogen storage, e.g., to alter the characteristics of well-known complex hydrides. Superalkalis are clusters having ionization energy lower than those of alkali metal atoms. These clusters possess not only unusual structures but also many fruitful applications. The compounds based on superalkalis can possess strong nonlinear optical responses. It has also been reported that superalkalis can be used to design alkalides and superbases. The underlying idea is that superalkalis is hypervalent clusters having strong reducing power. This tendency of superalkalis led them to bind with CO2 and NOx molecules and consequently, to capture or store these small molecules. Although the intriguing applications of superalkalis are continuously increasing, the potential of superalkalis in hydrogen storage remains to be explored. The proposed project aims to unravel this hidden aspect of superalkalis, which might be useful for future technological applications.