D-glucose and its analogue, d-glucosamine, as potential hydrogen storage materials: A quantum mechanical study

Abstract

Cellulose and chitosan monomers have been studied as potential hydrogen storage materials with good gravimetric density and strong binding strength for the adsorption of hydrogen molecules. DFT calculations have been employed to examine the various available positions on the biomolecules for efficient hydrogen adsorption. FMO and NBO analysis revealed the strength of non-bonded interactions between adsorbent (cellulose, chitosan) and adsorbate (H2 molecules). MEP analysis helped understand the charge separation upon H2 adsorption at the available sites. The strong interaction is attributed to the presence of polar hydroxyl groups on the carbon backbone, which interacts with hydrogen through dipole-induced dipole interactions between the hydroxyl oxygen and H2 molecules. Topological analysis for real space functions like electron density, ELF, LOL, NCI, and electrostatic potential was used to establish the nature of interactions. These findings can significantly impact the design of new hydrogen storage materials based on naturally available biopolymers with high hydrogen storage capacity at ambient temperature.