Efficient hydrogen storage on Al decorated C24N24: a DFT study

Abstract

H₂ storage and capture are critical components in the development of clean and sustainable hydrogen energy. The current work investigates the H₂ adsorption properties and storage on the Al-decorated porphyrin-like small porous C₂₄N₂₄ cluster using density functional theory calculations. Each Al site in the Al₆C₂₄N₂₄ cluster can adsorb up to five H₂ molecules, with an average adsorption energy of −0.30 eV. The impact of temperature and pressure on the hydrogen storage capacity of Al-decorated C₂₄N₂₄ clusters is also studied. A Kubas type mechanism and electrostatic interactions are found to be essential in the adsorption of H₂ molecules on the Al-decorated C₂₄N₂₄. According to our findings, Al₆C₂₄N₂₄ has a gravimetric density of 7.1 wt% H₂. These findings demonstrate that the Al-decorated C₂₄N₂₄ may be a potential candidate for reversible H₂ storage under normal conditions.