Furfural is one of the top valuable building block chemicals, the selective production of furfural from biomass has attracted increasing concerns in recent years. In this work, a novel method for the selective production of furfural through cellulose catalytic pyrolysis with WO 3 /γ-Al 2 O 3 was reported, and the synergistic effect between γ-Al 2 O 3 and WO 3 was explored. Compared with cellulose pyrolysis alone, the addition of γ-Al 2 O 3 improved the selectivity of furans and greatly inhibited the formation of sugars; while, WO 3 addition promoted the formation of levoglucosenone . When (20–40%) WO 3 /γ-Al 2 O 3 were added, the amount of sugars was further reduced, and the yields of furans (furfural and 2-methylfuran, in particular) were further increased at the same time. Under the optimum conditions (temperature = 600 °C, residence time = 15 s, and catalyst to cellulose mass ratio of 4), 30%WO 3 /γ-Al 2 O 3 showed the best performance, and the selectivity and yield of furfural were improved by nearly 100% and 300%, respectively, as compared with cellulose pyrolysis alone. In addition, compared with γ-Al 2 O 3 , the addition of 30%WO 3 /γ-Al 2 O 3 further increased the yield of furfural and 2-methylfuran to about 50% and 200%, respectively. The high selectivity and yields of furans with WO 3 /γ-Al 2 O 3 addition might be due to that WO 3 crystals in the composite promote the formation of levoglucosenone, which is further converted to additional furans through the Lewis acid sites of γ-Al 2 O 3 . The study may provide some meaningful advices for improving the production of furfural from green catalytic pyrolysis of cellulose.
Fuhang Mai,Zhe Wen,Yunfei Bai,Zewei Ma,Kai Cui,Kai Wu,Fei Yan,Hong Chen,Yongdan Li
A WO3/γ-Al2O3 catalyst prepared by an incipient-wetness impregnation method is employed in the selective conversion of enzymatic hydrolysis lignin (EHL) into various alkylphenols in supercritical ethanol. In the reaction, EHL is completely dissolved and converted into aliphatic and aromatic compounds with a total yield of 363.4 mg/g lignin at 320 °C for 8 h. The yield of aromatic compounds is 315.8 mg/g lignin, accounting for 86.9% of the total yield of the products, and the overall selectivity of alkylphenols reaches 67.5%. Compared to WO3 and H2WO4, the WO3/γ-Al2O3 shows a higher activity for the conversion of EHL in supercritical ethanol. Besides, ethanol is found to be the most effective solvent for the depolymerization of EHL with the WO3/γ-Al2O3 catalyst. The WO3/γ-Al2O3 keeps the high catalytic activity in three reuses.
Tetrahydrofurfuryl alcohol, a cost-effective biomass derivative, offers a sustainable path for synthesizing 1,5-pentanediol through hydrogenolysis. To develop the efficient production of 1,5-pentanediol from this alcohol, we have prepared a series of MgAl2O4-modified Pt/WOx/γ-Al2O3catalysts with varying compositions via impregnation–calcination methods. The physicochemical properties of these catalysts were subsequently characterized using diverse techniques. Characterization revealed that magnesia–alumina spinel modification enhanced Pt particle dispersion, CO adsorption on Pt/WOx/γ-Al2O3, reduced Pt particle reduction temperature, diminished the acid content in the catalysts, and increased the surface oxygen vacancy concentration. These alterations appear to influence the catalyst performance, though other factors cannot be ruled out. Catalytic activity tests demonstrated that magnesia–alumina spinel modification improved tetrahydrofurfuryl alcohol hydrogenolysis activity and the 1,5-pentanediol selectivity of Pt/WOx/γ-Al2O3. Optimal performance was achieved at 12% magnesia–alumina spinel loading, with a tetrahydrofurfuryl alcohol conversion of 47.3% and 1,5-pentanediol selectivity of 88.4%.