Effect of Cu particle size on hydrogenation of dimethyl succinate over Cu-SiO2 nanocomposite

Copper-silica nanocomposite with different Cu particle size was synthesized by changing the concentration of Cu nitrate solution by precipitation-deposition method. In this preparation method, the average Cu particle size was estimated to be 11 nm, 23 nm and 33 nm for 0.05 M, 0.8 M, and 2.0 M of Cu nitrate solution, respectively, which was confirmed by XRD and TEM. When the catalytic activities of these materials, Cu(76)/SiO2, were compared in hydrogenation of dimethyl succinate (DMS) at 265 degrees C and 25 bar, the product distribution as well as DMS conversion was highly dependent on Cu particle size. At WHSV 0.4 h(-1), Cu(76)/SiO2 with Cu particle size of 11 nm gave much higher tetrahydrofuran (THF) selectivity (93%) than that of 33 nm (20%) for the same DMS conversion (100%). The smaller Cu particles size was more advantageous to higher DMS conversion and higher THF selectivity, while the larger Cu particle size was more advantageous to higher gamma-butyrolactone (GBL) selectivity. It is concluded that THF could be produced selectively by controlling only Cu particle size without adding the acidic promoters such as alumina to Cu metallic sites. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.