One-Pot Hydrolysis-Hydrogenation of Potato Starch to Sorbitol Using Bifunctional Catalyst Ru/Cs₃HSiW₁₂O₄₀

The possibility of obtaining sorbitol from potato starch via one-pot hydrolysis-hydrogenation is demonstrated using bifunctional catalysts 0.3-3 wt % Ru/Cs3HSiW12O40 (Ru/Cs-HPA). It is found that a catalyst with 1 wt % Ru is the one most effective, since it has the optimum ratio of the concentrations of Bronsted and Lewis acid sites on the support's surface and a large specific surface area. The kinetics of the reaction with 1% Ru/Cs-HPA is studied and the observed energy of activation of the hydrolysis-hydrogenation of starch to sorbitol is found to be 80 +/- 8 kJ/mol. A kinetic model is proposed on the basis of experimental and published data. The model accurately describes the hydrolysis-hydrogenation of starch. The yield of sorbitol was 88 mol % (99 wt %) after 3 hours of the reaction using a catalyst with the optimum composition (1% Ru/Cs-HPA) at the optimum temperature (150 degrees C).