复合分子筛催化微晶纤维素水解

采用水热晶化法制备了HY/ZSM-5复合分子筛。通过XRD、SEM、N2-吸附脱附、NH3-TPD及吡啶吸附红外光谱等手段表征催化剂的结构和性质。结果表明,HY与HZSM-5复合后HY型分子筛完全被HZSM-5紧密包裹,形成致密的核壳结构。与机械混合物相比,复合分子筛微孔比表面积及孔体积均有所减少,总酸量略高,弱酸量小,而强酸量大,Br9nsted酸量与之相似,而Lewis酸量有所减少。将所制备的HY/ZSM-5复合分子筛催化剂应用于以离子液体氯化1-乙基-3-甲基咪唑鎓(Emim]Cl)为溶剂的纤维素水解反应中,与HY催化的纤维素水解相比,HY/ZSM-5催化纤维素水解反应获得的最佳葡萄糖收率由28.04%提高到38.78%,葡萄糖选择性由28.91%提高至48.29%。

Hydrolysis of cellulose catalyzed by composite zeolite

In this paper, HY/ZSM-5 composite zeolite was prepared by hydrothermal method and characterized by XRD, SEM, N2 adsorption-desorption, NH3-TPD and Py-FTIR. The results indicated that HY was completely encapsulated by HZSM-5 and formed a core-shell morphology of HY/ZSM-5 composite zeolite. Compared with the mechanical mixture, the composite zeolites show lower microporous surface area and microporous volume, higher quantity of total and strong acid sites, lower quantity of weak acid sites, the similar Br?nsted acid amount and the reduced Lewis acid amount. Cellulose was hydrolyzed in 1-ethyl-3-methylimidazolium chloride (Emim]Cl) using HY/ZSM-5 as catalyst. Compared with the hydrolysis reaction catalyzed by HY zeolite, the optimal glucose yield could be significantly improved from 28.04% to 38.78%, and the glucose selectivity improved from 28.91% to 48.29%. The mechanical mixture and HZSM-5 also applied as catalysts to the hydrolysis of cellulose, the glucose yields were only 24.47% and 15.27% respectively.