Self-Activating Catalyst for Glucose Hydrogenation in the Aqueous Phase under Mild Conditions

The search for efficient routes for the production of sorbitol from starch-derived glucose is of great interest and importance because sorbitol is a highly attractive chemical for different applications, such as a building block for the synthesis of fine chemicals, additives in food, and the cosmetic and paper industries. In this study, the (RuO2)0.038·(SiO2)0.962 nanomaterial was prepared by a one-pot sol–gel route. The performances of the gel-derived catalyst in the glucose hydrogenation reaction, in the aqueous phase and mild conditions, are reported and compared with those of a commercial Ru/C catalyst. When the commercial Ru/C catalyst was used, a high activity and no selectivity loss were observed, but the activity dramatically dropped soon after the first cycle; on the contrary, the gel-derived catalyst activity increased during the first three cycles. The different catalytic behavior was ascribed to the morphological distribution of the Ru active phase in the gel-derived catalyst. Actually, the adopted synthesis procedure leads to a multimodal size distribution of the Ru nanoparticles, which are fairly stabilized by a combined interaction with the SiO2 support and the reaction environment, which proved to be active in obtaining a self-activating catalyst.