▎ 摘　　要

Beryllium (Be)-decorated graphene with 585 double carbon vacancy defect and nitrogen-doped porphyrin defect are investigated for hydrogen storage applications using the first principle calculation based on density functional theory. It is found that the Be atom disperses well in the defective sites of graphene and prevents clustering. For the case of Be-decorated 585 double vacancy graphene, only two H-2 molecules are adsorbed via Kubas interaction with the stretched H-H bond length of 0.8A degrees. In Be-decorated porphyrin defect graphene system, four H-2 molecules are molecularly chemisorbed with the H-H bond length of 0.77 A degrees The chemisorptions are due to the hybridization between Be-p orbital and the H-sigma orbital. The average binding energy of H-2 molecule is found to be 0.43 eV/H-2 which lies within the required range that can permit recycling of H2 molecules under ambient conditions.