Glucose Conversion into 5-Hydroxymethylfurfural over Niobium Oxides Supported on Natural Rubber-Derived Carbon/Silica Nanocomposite

Abstract

5-Hydroxymethylfurfural (HMF) is one of the most important lignocellulosic biomass-derived platform molecules for production of renewable fuel additives, liquid hydrocarbon fuels, and value-added chemicals. The present work developed niobium oxides (Nb2O5) supported on mesoporous carbon/silica nanocomposite (MCS), as novel solid base catalyst for synthesis of HMF via one-pot glucose conversion in a biphasic solvent. The MCS material was prepared via carbonization using natural rubber dispersed in hexagonal mesoporous silica (HMS) as a precursor. The Nb2O5 supported on MCS (Nb/MCS) catalyst with an niobium (Nb) loading amount of 10 wt.% (10-Nb/MCS) was characterized by high dispersion, and so tiny crystallites of Nb2O5, on the MCS surface, good textural properties, and the presence of Bronsted and Lewis acid sites with weak-to-medium strength. By varying the Nb loading amount, the crystallite size of Nb2O5 and molar ratio of Bronsted/Lewis acidity could be tuned. When compared to the pure silica HMS-supported Nb catalyst, the Nb/MCS material showed a superior glucose conversion and HMF yield. The highest HMF yield of 57.5% was achieved at 93.2% glucose conversion when using 10-Nb/MCS as catalyst (5 wt.% loading with respect to the mass of glucose) at 190 °C for 1 h. Furthermore, 10-Nb/MCS had excellent catalytic stability, being reused in the reaction for five consecutive cycles during which both the glucose conversion and HMF yield were insignificantly changed. Its superior performance was ascribed to the suitable ratio of Brønsted/Lewis acid sites, and the hydrophobic properties generated from the carbon moieties dispersed in the MCS nanocomposite.

Progress in Selective Conversion of 5‐Hydroxymethylfurfural to DHMF and DMF

“…[12][13] In order to make full use of biomass resource, fine chemicals, and biological liquid fuel oil can be prepared by hydrogenation, oxidation, hydrolysis, esterification, reductive depolymerisationenzymatic hydrolysis, and catalytic pyrolysis. [14][15][16][17][18][19][20][21][22][23][24][25][26] 5-hydroxymethylfurfural (HMF) is a very momentous platform compound, [27][28][29][30] HMF was obtained though the dehydration of biomass-derived carbohydrates, such as glucose, [31][32][33][34][35] fructose, [36][37][38][39][40] sucrose, [41][42][43][44][45] inulin, [46][47][48][49][50] cellobiose [51][52][53][54][55] and cellulose. [29,[56][57][58]…”

“…In order to make full use of biomass resource, fine chemicals, and biological liquid fuel oil can be prepared by hydrogenation, oxidation, hydrolysis, esterification, reductive depolymerisationenzymatic hydrolysis, and catalytic pyrolysis [14–26] . 5‐hydroxymethylfurfural (HMF) is a very momentous platform compound, [27–30] HMF was obtained though the dehydration of biomass‐derived carbohydrates, such as glucose, [31–35] fructose, [36–40] sucrose, [41–45] inulin, [46–50] cellobiose [51–55] and cellulose [29,56–60] . Microwave technology is a simple and efficient conversion technology that can convert biomass to HMF.…”

Mild Dealumination of H-ZSM-5 Zeolite for Enhanced Conversion of Glucose into 5-Hydroxymethylfurfural in a Biphasic Solvent System

“…As shown in Table 2, this result was attributed to an increased number of total acid sites, with especially strong acidity from 0.166 mmol/g to 0.224 mmol/g for the parent and dealuminated zeolite catalysts, respectively. Khumho et al [39] investigated the catalytic conversion of glucose into HMF over niobium oxides supported on carbon/silica nanocomposite. They found that the catalyst with the highest number of strong acid sites gave the highest yield of HMF.…”

Synthesis of 5‐hydroxymethylfurfural from glucose over carbon‐based acid–base bifunctional catalyst

“…With the increase in the consumption of fossil energy and high attention to environmental problems, the utilization of lignocellulosic biomass is believed to be an effective way to reduce energy dependence on fossil. 1 The conversion of lignocellulosic biomass into platform compounds, especially 5-hydroxymethylfurfural (5-HMF) has attracted more and more concerns since it is an important intermediate for producing a series of high-value-added products and high-quality fuels via selective oxidation, dehydration, hydroxyl aldol condensation, and hydrogenation reactions. 2 5-HMF has been widely considered an alternative to petroleum, 3,4 and expected to play a key role in chemical, fuel, medical, food fields, and so forth.…”