The Nature of Active Copper Species in Cu/SiO2 Catalysts for Hydrogenation of Methyl Acetate to Ethanol (PPT)

摘要

1. We successfully prepared a series of Cu/SiO2 catalysts with remarkable differences on state of Cu species and exclued the other factors' influence. 2. The conversion of MA grew linearly associated with the Cu (0) surface area increasement under a certain value. However, with more Cu (0) active sites, the samples catalytic activity increaed with enrichment of Cu (I) surface area. 3. These relationships strongly proved there was a synergy of active copper species on the hydrogenation of MA and indicated that when there is insufficient of Cu (0) species, the catalytic activity of hydrogenation determined by the activity of H2, whereas, it would be decided by the adsorption of methoxy and acyl species as the amount of surface Cu (0) achieved to a certain degree. 4. The calculated results showed the MA could be adsorbed by (Cu)_x~(δ+)/SiO2 but not activated by Cu (111). And the H2 is much easilier dissociated on Cu (111) than on (Cu)_x~(δ+)+/SiO2. These calculatedresults are agreed with the experiments data.