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Surface structures of Pt-Sn and Pt-Fe bimetallic catalysts have been investigated by means of Mssbauer spectroscopy, Pt-L_Ⅲ-edge EXAFS and H_2-adsorption. The results showed that the second component, such as Sn or Fe, remained in the oxidative state and dispersed on the γ-Al_2O_3 surface after reduction, while Pt was completely reduced to the metallic state and dispersed on either the metal oxide surface or the γ-Al_2O_3 surface. By correlating the distribution of Pt species on different surfaces with the reaction and adsorption performances, it is proposed that two kinds of active Pt species existed on the surfaces of both catalysts, named M_1 sites and M_2 sites. M_1 sites are the sites in which Pt directly anchored on the γ-Al_2O_3 surface, while M_2 sites are those in which Pt anchored on the metal oxide surface. M_1 sites are favorable for low temperature H_2 adsorption, and responsible for the hydrogenolysis reaction and carbon deposition, while M_2 sites which adsorb more H_2 at higher tem