Bimetallic Ru:Ni/MCM-48 catalysts for the effective hydrogenation of d-glucose into sorbitol

Abstract

Three different bimetallic Ru:Ni catalysts supported on a mesoporous silica MCM-48 were prepared by consecutive wet impregnations, with a total metal loading of ca. 3% (ww−1). Ru:Ni ratios spanned in the range of 0.15–1.39 (ww−1) and were compared with the corresponding monometallic Ni/MCM-48. The catalysts so prepared were characterized by X-Ray Diffraction, Transmission Electron Microscopy, adsorption/desorption of N2, Temperature Programmed Reduction, NH3 − TPD and Atomic Absorption, and tested in the liquid phase hydrogenation of d-glucose into sorbitol in the temperature range 120–140°C under 2.5MPa of H2 pressure. Bimetallic catalysts with Ru:Ni ratios higher than 0.45 enhanced the catalytic behavior of the monometallic Ni/MCM-48 in the reaction, increasing the reaction rate and showing complete selectivity to sorbitol by minimizing the production of mannitol. Ru:Ni/MCM-48 (0.45) was recovered from the reaction media and tested for three reaction cycles, showing good stability under the selected experimental conditions.