Density Functional Theory Study Of Li-Functionalized Nanoporous R-Graphyne-Metal-Organic Frameworks For Reversible Hydrogen Storage

Hydrogen is the most convenient recourse to shift from fossil fuels to an efficient and sustainable source of energy in automobiles. Achieving a high hydrogen weight percentage while storing hydrogen is the prime challenge in using hydrogen fuel. In the current study, a nanoporous metal-organic framework of 2.069 nm pore size having R-graphyne as a linker (G(R)-MOF) is reported for the first time. Employing density functional theory, the hydrogen sorption characteristics of G(R)-MOF functionalized with Li and its mechanism are investigated. A Kubas-like mechanism is observed in the process of hydrogen adsorption with sorption energies in the 0.25-0.27 eV range, with the highest hydrogen weight percentage of 11.95%. It is observed during the van 't Hoff desorption and Born-Oppenheimer molecular dynamics study that G(R)-MOF reversibly stores hydrogen under operable thermodynamic conditions (100-300 K, 1-3 atm). G(R)-MOF stands out to be a prospective material for reversible hydrogen storage under the norms set by the Department of Energy, USA.