Chemoselective hydrogenation of aromatic aldehydes over SiO2 modified Co/γ-Al2O3

With benzaldehyde as a model compound, the hydrogenation of aromatic aldehydes to corresponding benzyl alcohols was investigated in a fixed-bed reactor. Co/gamma-Al2O3 doped with a amount of SiO2 displayed excellent catalytic performance for this reaction, Co/gamma-Al2O3 is modified by SiO2 in two ways, the strong interaction between metal oxide and support is obviously reduced, and also a large number of acid sites are diminished on the catalyst. The first aspect apparently facilitated the reduction of metal oxide, and improved the hydrogenation activity of the catalyst; while the second aspect greatly inhibited the hydrogenolysis of the -C-0 bond, and thus increased the selectivity toward benzyl alcohol. (C) 2014 Elsevier B.V. All rights reserved.