Effect of microsolvation on hydrogen trapping potential of metal ions

► The hydrogen adsorbing capacity of microsolvated metal ions in presence as well as absence of the counterions is analyzed. ► Computations are done at different levels of theory by using different functionals and basis sets. ► The interaction energy is computed also including BSSE correction. ► Interaction energies are favorable for hydrogen adsorption on the systems containing alkali metal ions. ► In presence of counterions, alkaline earth metal ions bound more H2 molecules than alkali metal ions.