382964 The Nature of Active Copper Species in Cu/SiO2 Catalysts for Hydrogenation of Methyl Acetate to Ethanol
Ethanol is becoming much more popular since it can be used solely or blended with hydrocarbons as fuel alternatives. As an environmental friendly process with high atom economy, the indirect route for ethanol synthesis from syngas via methyl acetate hydrogenation has attracted great attention in the worldwide. Although Cu/SiO2 catalyst has been widely studied in methyl acetate hydrogenation, there is still some controversy as to the catalytic reaction mechanism of Cu(0) and Cu(I).
With the investigation of Cu/SiO2 catalysts varied the surface Cu(0) and Cu(I) site densities, we solely determined the quantitative relationship between amount of two active copper species and catalytic performance for methyl acetate hydrogenation separately. As the amount of surface Cu(0) achieved to a certain degree, the catalytic performances were linearly associated with the amounts of surface Cu(I). Otherwise, the surface Cu(0) site density was primarily responsible for the activity of the catalysts. In addition, sintering-resistant Cu@SiO2 core-shell catalysts with sub-5nm cores were prepared to investigate the catalytic reaction mechanism with the sole Cu(0) as active site. And the effect of Cu nanoparticle size on hydrogenation of methyl acetate over Cu@SiO2 core-shell catalysts was studied as well.