H2-Anion Interactions and Energy Calculations for Imidazolium-based Ionic Liquids as Hydrogen Storage Materials

Abstract

The aims of this study are to explore the molecular hydrogen-anion interactions and assess the energy calculations in imidazolium-based compounds. The stable modes were structurally discussed after the achieving optimizations by density functional theory. It is concluded that the interaction energies were very weak against the strong interaction lengths. The impacts of the loaded molecular hydrogen to the imidazolium-based structure were discussed by the frontier molecular orbital analysis. While the amounts of H2 involved to the interaction increased, the changes in the energy gap were calculated. The bonding interactions on the cation–anion and molecular nH2–anion were compared.