Hydrogen storage capacity of vanadium functionalized [2,2]paracyclophane: A density functional theory study

Abstract

This work reports the hydrogen storage capacity and properties of V atom functionalized [2,2]paracyclophane (PCP22) using dispersion corrected density functional theory (DFT-D2) calculations. The V atom was found to be bound firmly with the PCP22 via the Dewar mechanism with a binding energy of 1.88 eV. Each V atom functionalized on PCP22 can adsorbed a maximum up to 5H2 molecules with a hydrogen gravimetric density of 6.10 wt%, which is fairly above the target set by US-DOE. The hydrogen molecules are adsorbed with the host material by the Kubas-type interaction with an average adsorption energy in the range of 1.02 eV and 0.48 eV, which was the physisorption type of adsorption. Thus, we believe that our studied system PCP22-2 V can be proposed as a practically viable system for hydrogen storage at standard temperature and pressure.