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 °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 γ-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.