Adsorption of molecular hydrogen on inorganometallic complexes B2H4M (M=Li, Be, Sc, Ti, V)

Abstract

Molecular interaction between hydrogen molecules and B2H4M (M=Li, Be, Sc, Ti, V) complexes has been studied using the DFT method (M06 functional) and 6-311++G** basis set. The hydrogen uptake capacity of the complexes considered is higher than the target set by the US Department of Energy (5.5 wt% by 2020). The metal atom bound strongly to the B2H4 substrate. Adsorption of molecular hydrogen on Be-, Ti-, and V-decorated complexes is thermodynamically possible for all the pressures and temperatures considered whereas it is unfavorable for Li-decorated complexes for all the pressure and temperatures. For the Sc-doped complexes, adsorption of molecular hydrogen is favorable below 330 K and entire pressure range considered. All the H2 adsorbed complexes are kinetically stable. For all the complexes, the interaction between the inorganometallic complexes and the H2 molecules adsorbed is attractive whereas that between adsorbed H2 molecules is repulsive. We have also performed molecular dynamics simulations to confirm the same number of H2 molecule adsorption from the simulations and DFT calculations.