Efficient Epimerization of Glucose to Mannose over Molybdenum‐Based Catalyst in Aqueous Media
Hong Hu, Shaoru Liu, Weizi Zhang, Jiahuan An, Haian Xia
Abstract
Abstract Herein, the high activity and selectivity of activated carbon‐supported molybdenum oxide catalysts (Mo/AC) in the epimerization of glucose to mannose is described. The catalysts afforded near‐equilibrium glucose conversion (29.2 %) and selectivity (94.5 %) toward mannose in the epimerization of glucose. The catalysts were characterized by X‐ray diffraction, UV‐Vis diffuse reflectance spectroscopy, and X‐ray photoelectron spectroscopy. It was found that the Mo/AC catalysts were mainly composed of highly dispersed MoO 2 and MoO 3 species. Compared to the soluble MoO 3 catalyst, Mo/AC showed higher stability and better catalytic performances in the epimerization of glucose to mannose. Further, the deactivation of Mo/AC catalysts was attributed to the leaching of molybdenum oxides. Isotope labeling experiments revealed that the deuterium atom at the C‐1 position of mannose is formed by glucose‐D2 epimerization.