Hydrogenation of Succinic Acid to Tetrahydrofuran Over Ruthenium–Carbon Composite Catalyst: Effect of Catalyst Preparation Condition

Ruthenium–carbon composite (Ru–C-X) catalysts were prepared by a single-step surfactant-templating method at different sucrose/P123 molar ratio (X = 3, 5, 7, 9, 11, and 15). Ru–C-X (X = 3, 5, 7, 9, 11, and 15) catalysts were characterized by BET, nitrogen adsorption–desorption isotherm, XRD, and HR-TEM analyses. Liquid-phase hydrogenation of succinic acid to tetrahydrofuran (THF) was carried out over Ru–C-X catalysts in a batch reactor. The effect of sucrose/P123 molar ratio on the physicochemical properties and catalytic activities of Ru–C-X catalysts (X = 3, 5, 7, 9, 11, and 15) was investigated. It was revealed that Ru–C-X composite catalysts showed different ruthenium particle size depending on sucrose/P123 molar ratio. Characterization results showed that an optimal sucrose/P123 molar ratio was required to achieve fine dispersion of ruthenium in the Ru–C-X catalysts. Yield for THF in the hydrogenation of succinic acid increased with decreasing average ruthenium particle size of Ru–C-X catalysts. Ruthenium particle size served as an important factor determining the catalytic performance of Ru–C-X in the hydrogenation of succinic acid to THF. Among the catalysts tested, Ru–C-9 with the smallest ruthenium particle size showed the highest yield for THF.