Jing Guo,Shanhui Zhu,Youliang Cen,Zhangfeng Qin,Jianguo Wang,Weibin Fan
A series of ordered mesoporous Nb x W (8 − x) oxides with tunable Nb/W ratio were successfully synthesized by evaporation-induced self-assembly method. The mesoporous structure, morphologies, surface chemical state, and acidic properties of these catalysts were fully characterized by low-temperature sorption of N 2 , small-angle and wide-angle XRD, TEM, Raman, XPS, and Py-IR. It was shown that the Nb x W (8 − x) oxides created large amounts of Lewis as well as Brønsted acid sites, which promoted the isomerization of glucose to fructose followed its dehydration to 5-hydroxymethylfurfural (HMF). Mannose was also formed via the epimerization of glucose. Of them, the mesoporous Nb 4 W 4 exhibited the best catalytic activity with a comparatively low E a about 90.2 kJ/mol and good stability in aqueous medium. The kinetic behavior revealed that Lewis acid sites facilitated to glucose-to-fructose isomerization while Brønsted acid sites promoted the dehydration of fructose to form HMF.
Haonan Qu,Bingyi Liu,Guohua Gao,Yiming Ma,Yanmei Zhou,Hua Zhou,Li Li,Yonghong Li,Shengjian Liu
Levulinic acid (LA) is a versatile key building block in the conversion of carbohydrates and it is an important basic chemical with various potential uses. MIL-100(Fe) loading with insoluble lysine functionalized phosphotungstic acid (Lys-PM 2 ) as heterogeneous catalysts have been synthesized for the conversion of glucose to LA in water. The optimized yield of LA is obtained by using Lys-PM 2 to catalyze glucose conversion is comparable to the majority of effective catalysts. The highest yield of LA (57.9%) is obtained at 150 °C for 9 h with 100 mg glucose and 25 mg Lys-PM 2 , since the Brønsted acidity and Lewis acidity of Lys-PM 2 . And the catalyst is able to recycle at least four times. It demonstrates the potential of Lys-PM 2 for the conversion of biomass.
危险品化学品经营许可证（带存储）