Lei Zhang,Bingfeng Chen,Ti Zhou,Xiaomeng Cheng,Minghua Dong,Ye Liu,Huizhen Liu,Qingling Xu,Buxing Han
The conversion of carbohydrates into 5-hydroxymethylfurfural (HMF), a vital and valuable platform chemical, is sought after in industrial applications but poses significant challenges. In this research, we engineered an ultra-thin layer HTaMoO 6 catalyst using ball-milling/liquid-exfoliation technique, demonstrating its efficiency in catalyzing the transformation of carbohydrates to HMF. In contrast to the conventional method utilizing tetra(n-butylammonium) hydroxide as the intercalation agent, the ball-milling/liquid-exfoliation technique not only reduces catalyst preparation time (within 12 h) but also enhances the efficient intercalation, leading to the formation of an ultra-thin layer structure. The resulting catalyst exhibits high total acidity, a favorable Brønsted/Lewis acid ratio, and improved accessibility of active sites due to the thin layer structure post-exfoliation. Compared with bulk LiTaMoO 6 , the ultrathin layer HTaMoO 6 catalyst enables complete fructose dehydration with an HMF yield reaching 89.1 % under moderate reaction conditions (120 °C, 1 h) and 47.2 % yield of HMF is obtained from sucrose at 130 °C. This work provides a new method to fabricate the solid acid for the transformation of carbohydrates.
A catalytic routine was developed for kraft lignin depolymerization in dioxane-water systems, in which the catalyst HTaMoO 6 with strong Bronsted acidity and a hydrogenation catalyst (Rh/C) were employed simultaneously. The performance of the composite catalysts was tested in a series of experiments with various reaction temperatures, reaction time and catalyst ratios. Under the optimized conditions, a higher petroleum ether soluble fraction yield of 58.7% was obtained at 320 °C for 24 h. Besides, a higher liquid product yield of 95.6% was achieved at 290 °C for 2 h. Specially, the main compositions of the petroleum ether soluble fraction are monomers and dimers, which can be used as liquid fuel. These results demonstrated that the composite catalyst HTaMoO 6 -Rh/C can effectively catalyze the depolymerization of the kraft lignin into small molecule liquid fuel components.