A theoretical study of nanoporous organic molecules for hydrogen storage

The adsorption of molecular hydrogen on model nanoporous organic molecules is studied through computational simulations based on the pseudopotential density functional method. The sorption energy of hydrogen and its diffusion through the porous molecules are particularly investigated. It is found that the sorption energy of hydrogen is in a marginal range between physisorption and chemisorption. The equilibrium pressure and desorption temperature of hydrogen on the molecules are also calculated by including the temperature and pressure dependence of hydrogen entropy. The desorption temperature is estimated to be about ∼270 K, which suggests that the organic molecules can be promising media or components for hydrogen storages operating at room temperature or higher.