Adsorption and dissociation of hydrogen on Li3N surface: A first principles study

The adsorption and dissociation of hydrogen on Li3N surface are studied by density functional theory calculations and experiment. The surface energies of four low index surfaces (001), (010), (100), and (010) are calculated. Results show that (001) has the lowest surface energy of 1.28J∕m2 compared to other three surfaces; therefore, (001) surface is selected for H2 adsorption and dissociation study. For H2 molecule adsorption, results show that the most stable adsorption site is on the N top with adsorption energy of 0.14eV. For the dissociated hydrogen atoms, the most stable adsorption site is on two N tops, with adsorption energy of 5.12eV per H atom. The calculated energy barrier for H2 dissociation is about 0.79eV, which is smaller than that of experimental value of 1.22eV.