Hydrogen Adsorption and Storage in Heteroatoms (B, N) Modified Carbon-Based Materials Decorated with Alkali Metals: A Computational Study

Abstract

The hydrogen adsorption and storage capacity on various carbon-based ring materials decorated with alkali metal ions have been systematically investigated by using quantum chemistry calculations. To improve the bonding ability between H2 molecules and carbon-ring based molecular complexes, we also explain the strategy of modifying the carbon ring materials by substituting carbon element to boron or nitrogen element (up to three atoms). Our calculations show that the Li+-, Na+-, and K+-decorated carbon-based molecular complexes with B- and N-substitution enhance the hydrogen storage capacity. The Mulliken charge analysis is performed to illustrate the interaction between H2 and M+@carbon-ring complex. The number of binding H2 molecules on the M+-carbon-ring complexes (M+ = Li+, Na+, and K+) depends on ionic radii of the metal cations. It is found that corresponding gravimetric density are predicted to be 11.21–13.95 and 10.42–13.24 wt % for the B- and N-substituted complexes, respectively.