Revealing the interfacial phenomenon of metal-hydride formation and spillover effect on C48H16 sheet by platinum metal catalyst (Pt (n=1-4)) for hydrogen storage enhancement

Abstract

Hydrogen is a worldwide green energy carrier, however due its low storage capacity, it has yet to be widely used as an energy carrier. Therefore, the quantum chemical method is being employed in this investigation for better understand the hydrogen storage behaviour on Pt (n = 1-4) cluster decorated C48H16 sheet. The Pt(n = 1-4) clusters are strongly bonded on the surface of C48H16 sheet with binding energies of −3.06, −4.56, −3.37, and −4.03 eV respectively, while the charge transfer from Pt(n = 1-4) to C48H16 leaves an empty orbital in Pt atom, which will be crucial for H2 adsorption. Initially, the molecular hydrogen is adsorbed on Pt(n = 1-4) decorated C48H16 sheet through the Kubas interaction with adsorption energies of −0.85, −0.66, −0.72, and −0.57 eV respectively, while H–H bond is elongated due to the transfer of electron from σ (HH) orbital to unfilled d orbital of the Pt atom, resulting in a Kubas metal-dihydrogen complexes. Furthermore, the dissociative hydrogen atoms adsorbed on Pt(n = 1-4) decorated C48H16 sheet have adsorption energies of −1.14 eV, −1.02 eV, −0.95 eV, and −1.08 eV, which are greater than the molecular hydrogen adsorption on Pt(n = 1-4) cluster supported C48H16 sheet with lower activation energy of 0.007, 0.109, 0.046, and 0.081 eV respectively. To enhance the dissociative hydrogen adsorption energy, positive and negative external electric fields are applied in the charge transfer direction. Increasing the positive electric field makes H–H bond elongation and good adsorption, whereas increasing the negative electric field results H–H bond contraction and poor adsorption. Thus, by applying a sufficient electric field, the H2 adsorption and desorption processes are can be easily tailored.