Dehydration of Glucose to 5-Hydroxymethylfurfural Using Nb-doped Tungstite.
Dehydration of Glucose to 5-Hydroxymethylfurfural Using Nb-doped Tungstite.
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DOI：
10.1002/cssc.201600649
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发表时间：
2016-09-08
期刊：
影响因子：
8.4
通讯作者：
Hensen, Emiel J. M.
中科院分区：
文献类型：
--
作者：
Yue, Chaochao;Li, Guanna;Pidko, Evgeny A.;Wiesfeld, Jan J.;Rigutto, Marcello;Hensen, Emiel J. M.
葡萄糖脱水为5-羟甲基糠醛（HMF）在木质纤维素生物质的价值稳定的背景下仍然是一个重要的问题。WCl 6和NbCl 5的水解导致在低Nb含量下沉淀含Nb的钨酸盐（WO 3·H2O）以及在较高Nb含量下沉淀钨酸盐和铌酸的混合物。钨酸盐是一种很有前途的葡萄糖脱水制羟甲基糠醛的催化剂。与Nb 2 O 5相比，由于（混合）氧化物的低布朗斯台德酸度，形成的副产物较少。在水中，由于平衡的刘易斯和布朗斯台德酸性，对于具有低Nb含量的Nb-W氧化物，获得了HMF的最佳产率。在THF/水中，强刘易斯酸性和弱布朗斯特酸性导致反应通过异构化为果糖和果糖脱水为部分脱水的中间体进行，其通过LC-ESI-MS鉴定。向反应混合物中加入HCl导致该中间体快速脱水为HMF。对于所有的钨酸盐催化剂，以这种方式获得的HMF产率为约56%。密度泛函理论计算表明，钨酸盐表面的刘易斯酸中心可以将葡萄糖异构化为果糖。W被Nb取代通过稳定去质子化的葡萄糖吸附物降低了葡萄糖异构化的整体活化势垒。
Dehydration of glucose to 5‐hydroxymethylfurfural (HMF) remains a significant problem in the context of the valorization of lignocellulosic biomass. Hydrolysis of WCl6 and NbCl5 leads to precipitation of Nb‐containing tungstite (WO3⋅H2O) at low Nb content and mixtures of tungstite and niobic acid at higher Nb content. Tungstite is a promising catalyst for the dehydration of glucose to HMF. Compared with Nb2O5, fewer by‐products are formed because of the low Brønsted acidity of the (mixed) oxides. In water, an optimum yield of HMF was obtained for Nb–W oxides with low Nb content owing to balanced Lewis and Brønsted acidity. In THF/water, the strong Lewis acidity and weak Brønsted acidity caused the reaction to proceed through isomerization to fructose and dehydration of fructose to a partially dehydrated intermediate, which was identified by LC‐ESI‐MS. The addition of HCl to the reaction mixture resulted in rapid dehydration of this intermediate to HMF. The HMF yield obtained in this way was approximately 56 % for all tungstite catalysts. Density functional theory calculations show that the Lewis acid centers on the tungstite surface can isomerize glucose into fructose. Substitution of W by Nb lowers the overall activation barrier for glucose isomerization by stabilizing the deprotonated glucose adsorbate.
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DOI：
10.1039/a803886d
发表时间：
1998-10-07
期刊：
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS
影响因子：
--
作者：
Cairon, O;Chevreau, T;Lavalley, JC
通讯作者：
Lavalley, JC
影响因子：
16.6
作者：
Pidko, Evgeny A.;Degirmenci, Volkan;Hensen, Emiel J. M.
通讯作者：
Hensen, Emiel J. M.
影响因子：
8.6
作者：
Long, Run;English, Niall J.
通讯作者：
English, Niall J.
影响因子：
3.1
作者：
Amarasekara, Ananda S.;Williams, LaToya D.;Ebede, Chidinma C.
通讯作者：
Ebede, Chidinma C.
影响因子：
9.8
作者：
Chheda, Juben N.;Roman-Leshkov, Yuriy;Dumesic, James A.
通讯作者：
Dumesic, James A.