Open AccessSynergetic Effect of Brønsted/Lewis Acid Sites and Water on the Catalytic Dehydration of Glucose to 5‐Hydroxymethylfurfural by Heteropolyacid‐Based Ionic Hybrids
Author(s) -
Zhao Pingping,
Cui Hongyou,
Zhang Yunyun,
Zhang Yuan,
Wang Yong,
Zhang Yali,
Xie Yujiao,
Yi Weiming
Publication year - 2018
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201800138
Subject(s) - dehydration , levoglucosan , chemistry , catalysis , yield (engineering) , lewis acids and bases , 5 hydroxymethylfurfural , sulfonic acid , brønsted–lowry acid–base theory , dehydration reaction , organic chemistry , ionic liquid , biochemistry , materials science , aerosol , biomass burning , metallurgy
The effective dehydration of glucose to 5‐hydroxymethylfurfural (HMF) has attracted increasing attention. Herein, a series of sulfonic‐acid‐functionalized ionic liquid (IL)–heteropolyacid (HPA) hybrid catalysts are proposed for the conversion of glucose to HMF. A maximum total yield of HMF and levoglucosan (LGA; ≈71 %) was achieved in the presence of pyrazine IL‐HPA hybrid catalyst [PzS]H 2 PW in THF/H 2 O–NaCl (v/v 5:1). The mechanism of glucose dehydration was studied by tailoring the Brønsted/Lewis acid sites of the hybrid catalysts and altering the solvent composition. It was found that water and heteropolyanions have a significant effect on the reaction kinetics. Heteropolyanions are able to stabilize the intermediates and promote the direct dehydration of glucose and intermediate LGA to HMF. A small amount of water could facilitate the conversion of glucose to LGA and suppress the dehydration of LGA to levoglucosenone. In addition, the synergetic effect of Brønsted/Lewis acid sites and a little water was conducive to accelerated proton transfer, which improved the yield of HMF from glucose dehydration.