Hydrogen adsorption of Li functionalized Covalent Organic Framework-366: An ab initio study

•Hydrogen adsorption of Li decorated Covalent Organic Framework-366 was investigated.•Hydrogen binding energies are ranged from 0.03 to 0.16 eV/H2 for 1–3 H2 loadings.•Hydrogen uptake at room temperature and ambient pressure is 1.05 wt%.•Hydrogen uptakes are rather high compared to other Covalent Organic Frameworks.•Decorating Li on COF-366 is a successful strategy for improving hydrogen uptake.

This work deals with the investigations of hydrogen adsorption energies of the Li functionalized Covalent Organic Framework-366 (COF-366) by using the density functional theory method. Based on total energy calculations, it was found that Li atom is preferentially trapped at the center site of the tetra(p-amino-phenyl) porphyrin and the onN site of a terephthaldehyde chain. Moreover, hydrogen adsorption energies per H2 for 1–3 H2 loadings range from 0.03 to 0.22 eV. According to ab initio molecular dynamics simulations, our results found that hydrogen capacities of Li functionalized COF-366 at ambient pressure are 2.06, 1.58, and 1.05 wt% for 77, 150 and 298 K, respectively.