Sorbitol synthesis from glucose with nickel-based sol-gel catalysts

In this study, nickel-based catalysts prepared by the sol-gel method were used to investigate the synthesis of sorbitol from glucose by hydrogenation reactions. A significant difference in product yield was obtained with SiO2-supported catalysts compared to ZrO2-supported catalysts. The increase in the Ni ratio of the Ni/SiO2 catalyst played an important role in the activity of the catalyst. Catalyst composition, especially the addition of copper to the catalyst structure, also played a key role in synthesis of sorbitol. A series of experiments were carried out to determine the optimum Ni-Cu ratio and reaction conditions at which the highest sorbitol yield and selectivity were obtained. A total 100% sorbitol yield was achieved using 15Ni15Cu/SiO2 catalyst at 175 degrees C during 5 h under 3.5 MPa H2 pressure. In order to reveal the stability of the catalyst, the reusability of the effective catalyst was investigated. In addition, the structure of the most active catalyst was characterized using X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), temperature programmed reduction (TPR), transmission electron microscopy (TEM) techniques, and BET surface area method.