A Single-Step Hydrolysis-Reduction of Potato Starch to Sorbite in the Presence of Bifunctional Catalyst Ru/Сs3HSiW12O40

It was shown that sorbite can be obtained from potato starch by its single-step hydrolysis-reduction in the presence of bifunctional catalysts 0.3–3 wt.%Ru/Cs3HSiW12O40 (Ru/Cs-HPA). Most efficient was the catalyst containing 1 wt.%Ru; this is related to the optimal concentration ratio of Broensted and Lewis acid sites on the support surface and a high specific surface area. The reaction kinetics in the presence of 1%Ru/Сs-HPA was studied and the apparent activation energy of the starch hydrolysis-reduction to sorbite (80±8 kJ/mol) was determined. The experimental and literature data were used to propose a kinetic model of the process, which describes quite adequately the hydrolysisreduction of starch. In the presence of the catalyst with the optimal composition (1%Ru/Cs-HPA) at the optimal temperature (150 °С), the yield of sorbite achieved 88 mol.% (99 wt.%) for 3 hours of the reaction.