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 8 nm, 15 nm and 26 nm for 0.05M, 0.8M, and 2.0M 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 ^oC and 25bar, the product distribution as well as DMS conversion was highly dependent on Cu particle size. At WHSV 0.5 h^-1, Cu(76)/SiO₂ with Cu particle size of 8 nm gave much higher tetrahydrofuran (THF) selectivity (68%) than that of 26 nm (16%) 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 g-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.