Synthesis Of Ruthenium Catalysts On Hydrogenation Of Glucose

Supported Ru catalyst was developed for hydrogenation of glucose to sorbitol. The cheap salt RuCl3 was selected as the precursor to prepare active Ru catalyst. The iodimetric analysis was employed to quantitate the glucose concentration during the reaction. The first order rate constants calculated on changes of glucose concentration with time was adopted for comparison of the activity of catalysts made in different ways. The influences of Ru deposition method, the types of support, pre-treatment of activated carbon, reduction conditions, and dechlorination by post-treatment on catalyst activity were investigated. It was found in experiment that deposition-precipitation with urea gave small Ru particles (~2.98nm, measured by CO adsorption) and best catalyst activity, and H2O2 is effective for pretreatment of active carbon. The temperature needed for complete reduction of the supported Ru catalysts in hydrogen was around 220oC, as measured by temperature programmed reduction (TPR) test. Though hydrogen reduction can get rid of chloride in some extent, washing with proper detergent after calcination seems more effective for dechlorination and promoted the activity of the catalyst substantially. A 3.79 wt.% Ru/C catalyst prepared at the optimized conditions was tested at 4MPa and 120 oC and measured a 1st-order rate constant as 0.533 (L/s·kg-cat), which is much higher than 0.422(L/s·kg-cat) for a commercial 5% Ru/C at the same conditions.