Abstract: The adsorption behaviors of H₂ at the positions of top,bridge,HCP,and FCC on the Ni(111) surface are compared and the respetive vertical distanees between the atom H and the atomic layer Ni are studied.The adsorption behavior at HCP and FCC is stable,while that at bridge adsorption position is not very stable,which is easy to shift to HCP bit adsorption.The adsorption energy at the four different positions was calculatedand obtained as:E_ad-top=－11.622 kJ·mol^-1，E_ad-bridge=－12.036 kJ·mol^-1，E_ad-hcp=－12.047 kJ·mol^-1，E_ad-fcc=－12.078 kJ·mol^-1.The results indicate that four kinds of adsorption of H₂ on surface Ni(111) belong to  chemical adsorption.The adsorption behavior of H₂ on surface Pt(111),Rh(111) and Rh(111) need further research.

Key words: hydrogen, metal catalyst, adsorption behavior