Zeolite-promoted transformation of glucose into 5-hydroxymethylfurfural in ionic liquid
- 能源院－已发表论文 
A variety of zeolite catalysts were investigated for the conversion of glucose into 5-hydroxymethylfurfural (HMF) in ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), and the results revealed that Hp-zeolite with a unique BEA structure and a moderate Si/Al ratio of 25 possessed the highest catalytic activity, which resulted in 50.3% HMF yield with 80.6% glucose conversion at a reaction temperature of 150 degrees C for only 50 min. In the presence of Hp-zeolite (Si/Al = 25) and [BMIM]Cl, the reaction kinetics for the conversion of glucose into HMF was studied and determined to be in accordance with a first-order reaction rate equation, and the activation energy and pre-exponential factor were 97.4 kJ mol(-1) and 2.2 x 10(10) min(-1), respectively. Moreover, a plausible mechanism involving the isomerization of glucose into fructose followed by the dehydration of fructose into HMF was proposed on the basis of the synergistic catalytic effect between Lewis acid sites and Bronsted acid sites of Hp-zeolite. Hp-zeolite (Si/Al=25) could be easily regenerated via a simple calcination, and a similar HMF yield with the first reaction run was observed in the seventh reaction run. More importantly, Hp-zeolite (Si/Al = 25) and [BMIM]Cl were also confirmed to be an excellent combination for the conversion of other carbohydrates such as fructose, sucrose, maltose, cellobiose, starch and cellulose into HMF. (C) 2014 Elsevier B.V. All rights reserved.