Isomerization Of Glucose Research Articles

Catalytic conversion of glucose to 5-hydroxymethylfurfural productions over sulphated Ti-Al2O3 catalysts

Titanium-alumina (Ti-Al2O3) composites with Al/Ti 10 ratio were prepared by a sol-gel method. The catalysts were prepared via three different methods such as solution, hydrothermal, and vapour phase using sulfuric acid, thiourea, and dibenzyl polysulfide (DBPS) as precursors, respectively. Ti-Al2O3 (10) composite material enhanced the isomerization of glucose to fructose. Sulfidation of catalysts played an important role in catalytic conversion of glucose as well as fructose dehydration. Glucose conversion of >97% with 65% of 5-hydroxymethylfurfural (HMF) was achieved using a superior H-SO42-/Ti-Al2O3 (10) catalyst at 170 °C, 200 mg of catalyst, time 4 h, and NaCl-H2O/THF. Inorganic salt like NaCl had a crucial role in final product separation as well as to control the side reaction. The material recycle capability was examined up to 6th cycles using the superior H-SO42-/Ti-Al2O3 (10) catalyst and the activities associated with catalyst physico-chemical properties were analyzed in detail.

Endogenous calcium enriched hydrochar catalyst derived from water hyacinth for glucose isomerization

Water hyacinth is a major aquatic plant in ecological restoration which propagates rapidly, whereas its biomass waste lacks value-added utilization routes. To address this problem, we put forth an innovative two-step carbonization strategy to convert water hyacinth to catalyst for isomerization of glucose to fructose. Through combining the hydrothermal carbonization and pyrolysis, catalyst morphology including its carbon substrate and calcium salts was successfully engineered. The prepared hydrochar-based catalyst presented an outstanding catalytic performance, the optimal of which could obtain 31% fructose yield with 89% selectivity at 120 °C for 45 min in water and maintain the reactivity for at least three runs. The catalytic reactivity was derived from the crystallization of endogenous alkaline earth calcium in water hyacinth, which was comparable to catalysts doped with expensive metals. Besides, the equipment and energy requirements for preparation were quite low-demanding (calcined only at 400 °C for 1 h). This study not only pioneers a sustainable way to upcycle aquatic biomass, but also invents a low-cost and efficient catalyst for biorefinery through the production of engineered carbon.

Sn Doping on Ta2O5 Facilitates Glucose Isomerization for Enriched 5‐Hydroxymethylfurfural Production and its True Response Prediction using a Neural Network Model

AbstractHere, we describe the maximum production of 5‐HMF using glucose over Sn doped Ta2O5 in a binary solvent system. The analytical characterizations established that Sn4+ in the catalyst interacts with Ta2O5 and offers the Lewis acid sites favorable for glucose isomerization to fructose. Similarly, the Ta2O5 support offers both the Lewis and Brønsted acid sites to promote fructose dehydration to 5‐HMF. The catalyst provided favorable conditions for the sequential sugar(s) transformation, i. e., glucose isomerization followed by fructose dehydration, which resulted in a 5‐HMF yield as high as 57 % wt. and 80 % selectivity under modest reaction conditions in a water‐DMSO system using ST1 (1 % Sn on Ta2O5). The separate fructose to 5‐HMF conversion study verified the negligible influence of Sn on the dehydration reaction. Moreover, the catalyst's systematic sugar conversion enabled a >65 % fructose formation, which accounts for the enriched 5‐HMF synthesis. The neural network model best represented the 5‐HMF data (<4 % MAE for glucose and fructose conversions).

Synthesis and Characterization of Sn, Ge, and Zr Isomorphous Substituted MFI Nanosheets for Glucose Isomerization to Fructose

Various metals including Sn, Ge, and Zr have been successfully incorporated into the MFI nanosheets via a one-pot synthesis. The as-synthesized zeolites exhibit high external surface area and mesopore volume without large metal oxides aggregated on zeolite surfaces. Interestingly, the successful introduction of heteroatoms in MFI nanosheets can be confirmed by shifted XRD peaks corresponding to the unit cell expansion due to the replacement of metals into the framework. In addition, the UV-Vis absorbance spectra reveal that at the suitable metal loading the incorporated tetrahedral coordination of metal species in the zeolite framework has been obtained. To illustrate the benefits of the prepared catalysts, the glucose isomerization to fructose was carried out in a water/dioxane system. Obviously, the SnMFI-NS samples, containing the high dispersion of metal isomorphous species demonstrate the outstanding catalytic behavior in term of fructose selectivity (>85 %).

Conversion of organosolv pretreated hardwood biomass into 5-hydroxymethylfurfural (HMF) by combining enzymatic hydrolysis and isomerization with homogeneous catalysis

BackgroundOver the last few years, valorization of lignocellulosic biomass has been expanded beyond the production of second-generation biofuels to the synthesis of numerous platform chemicals to be used instead of their fossil-based counterparts. One such well-researched example is 5-hydroxymethylfurfural (HMF), which is preferably produced by the dehydration of fructose. Fructose is obtained by the isomerization of glucose, which in turn is derived by the hydrolysis of cellulose. However, to avoid harsh reaction conditions with high environmental impact, an isomerization step towards fructose is necessary, as fructose can be directly dehydrated to HMF under mild conditions. This work presents an optimized process to produce fructose from beechwood biomass hydrolysate and subsequently convert it to HMF by employing homogeneous catalysis.ResultsThe optimal saccharification conditions were identified at 10% wt. solids loading and 15 mg enzyme/gsolids, as determined from preliminary trials on pure cellulose (Avicel® PH-101). Furthermore, since high rate glucose isomerization to fructose requires the addition of sodium tetraborate, the optimum borate to glucose molar ratio was determined to 0.28 and was used in all experiments. Among 20 beechwood solid pulps obtained from different organosolv pretreatment conditions tested, the highest fructose production was obtained with acetone (160 °C, 120 min), reaching 56.8 g/100 g pretreated biomass. A scale-up hydrolysis in high solids (25% wt.) was then conducted. The hydrolysate was subjected to isomerization eventually leading to a high-fructose solution (104.5 g/L). Dehydration of fructose to HMF was tested with 5 different catalysts (HCl, H3PO4, formic acid, maleic acid and H-mordenite). Formic acid was found to be the best one displaying 79.9% sugars conversion with an HMF yield and selectivity of 44.6% and 55.8%, respectively.ConclusionsOverall, this work shows the feasibility of coupling bio- and chemo-catalytic processes to produce HMF from lignocellulose in an environmentally friendly manner. Further work for the deployment of biocatalysts for the oxidation of HMF to its derivatives could pave the way for the emergence of an integrated process to effectively produce biobased monomers from lignocellulose.

Isomerization and Epimerization of Glucose Catalyzed by Sn-Containing Mesoporous Silica

Herein, we propose methodologies for the direct syntheses of Sn-containing MCM-41, SBA-16, MCM-48 with tin loadings between 1.5 and 4.5%. The catalysts were active in the isomerization of glucose to fructose, and the sample containing 3.0% of Sn showed the highest selectivity. Compared to the other structures, Sn-MCM-48 displayed a lower selectivity to fructose and a higher one to mannose, which is due to the presence of K+ remaining from the synthesis gel. Interestingly, the TOFFru is similar for Sn-MCM-41(3.0%) and K+/Sn-MCM-48(3.0). For K+/Sn-MCM-48(3.0%), the TOFMan and TOFFru were comparable. The presence does not affect the rate of fructose formation, but it promotes side reactions that involve glucose epimerization to mannose and, more importantly, the decomposition of glucose to unidentified products. Indeed, the ratio (TOFFru+TOFMan)/TOFGlu was 0.79, 0.37, and 0.81 for Sn-MCM-41, K+/Sn-MCM-48, and Sn-SBA-16(3.0%). The lowest TOF for fructose formation was observed for Sn-SBA-16(3.0%), which can be attributed to the high contribution of Sn in high coordination and extra framework tin oxide. For the direct conversion of glucose to HMF, Sn-MCM-41(3.0%), K+/Sn-MCM-48(3.0%), and Sn-SBA-16(3.0%) were combined with HCl, reaching selectivities of 77, 73, and 67%, respectively. These results are comparable or superior to those previously reported.

Hydroxyapatite-based catalysts derived from food waste digestate for efficient glucose isomerization to fructose

Transforming biomass waste into cost-effective catalysts for chemical reactions provides new opportunity for biomass waste valorization. In this work, we examined the possibility of using food waste solid digestate as raw materials for the production of a heterogeneous catalyst for glucose isomerization to fructose, which is one of the important intermediates for the production of platform chemicals, hydrocarbon fuels and synthetic materials from biomass. Hydroxyapatite-based catalysts were obtained from food waste digestate by a coupled hydrothermal-calcination approach. In the hydrothermal treatment process, the addition of exogenous calcium can adjust the alkalinity of the catalyst, which is beneficial to improve the activity of the catalyst. The reaction parameters such as reaction temperature, reaction time and catalyst dosage have also been optimized. The catalyst showed excellent catalytic performance in the glucose isomerization reaction resulting in a high fructose yield of 32.3% with a reaction time of only 20 ​min at 80 ​°C in water. The catalyst can be reused after a simple regeneration without significant activity. This work provides a win-win strategy, which not only solves the problem of the disposal and utilization of digestate, but also expands the synthesis method of the glucose isomerization reaction catalyst.

Magnesium Impregnated on NaX Zeolite Synthesized from Cogon Grass Silica for Fast Production of Fructose via Microwave-Assisted Catalytic Glucose Isomerization

Fructose is a crucial intermediate in the production of several chemical platforms. Fructose is mainly produced from glucose isomerization either through immobilized enzymes or heterogeneous catalysts using a conventional heating source, and this is time-consuming. Thus, this work discloses a fast production of fructose via microwave-assisted catalytic glucose isomerization using Mg catalysts supported on NaX zeolite from cogon grass silica. The catalysts were prepared by the impregnation of magnesium nitrate solution and subsequently transformed into MgO on NaX by calcination. The effect of 3, 6 and 9 wt.% Mg content on NaX on the performance of glucose isomerized to fructose was tested at 90 °C for 15 min. The best catalyst was selected for studying the effect of reaction times of 5, 15, 30 and 60 min. Results from X-ray diffraction (XRD), N2 sorption and CO2 temperature-programmed desorption (CO2-TPD) suggested that crystallinity, surface area and micropore volume decrease but basicity increases with Mg content. The X-ray photoelectron spectroscopy (XPS) result confirmed the presence of mixed phases of MgO and Mg2CO3 in all catalysts. The glucose conversion enhanced with the Mg loading but the fructose yield gave the highest value with Mg of 6 wt.%, probably due to the tuning of high active sites and surface area. The greatest fructose selectivity and yield (71.9% and 25.8%) were obtained within 15 min by microwave-assisted catalytic reaction, shorter than the reported value in the literature, indicating a suitable reaction time. Mg (6 wt.%)/NaX catalyst preserves the original catalytic performance up to three cycles, indicating that it is a promising catalyst for fructose production.

Modelado de la isomerización de glucosa en un reactor de lecho empacado utilizando un nuevo enfoque del mecanismo de Briggs-Haldane

Nowadays, immobilized enzymes are utilized in several food industry applications. Some researches use apparent kinetic parameters in immobilized enzyme reactor systems, which are limited to such case studies. To enhance productivity in a packed bed reactor (PBR), a clear description of all the mechanisms (kinetic, intra-particle diffusive mass transport, fluid-particle convective mass transport, and axial dispersion) affecting the process should be established. The objective of this study was to model the isomerization of glucose in a PBR with calcium alginate beads (CAB), using an approach where the kinetic and diffusional mechanisms are described independently. The convective mass transfer (kL) and axial dispersion (Dz) coefficients were calculated from correlations. Validation was performed comparing predictions against experimental data (R2 = 0.907) of glucose conversion at the reactor’s outlet once steady state was reached. Under the study conditions, in contrast to the effect exerted by diffusive mass transport on fructose specific productivity, the effect of axial dispersion and convective mass transport is negligible. Analyzing different operation parameters via simulation, the particle size had the highest impact on the glucose bioconversion. By reducing the CAB size, the surface area is increased and thus the conversion. It is recommended to test new immobilizing agents or decreasing the CAB size, monitoring that immobilizing support preserves its stability and functionality.

Theoretical insight into the conversion of glucose to 5-hydroxymethylfurfural in subcritical water

The reaction mechanism of the isomerization of glucose to fructose and further dehydration of fructose to 5-hydroxymethylfurfural (5-HMF) in subcritical water was investigated by the dispersion-corrected density functional theory (DFT-D) method with Dmol3 package in Materials Studio. The implicit solvent model was used to evaluate the bulk solvation under the conductor-like screening model (COSMO) approach, in which a dielectric constant (ɛ) of 27 was used to represent the subcritical water at 523.15 K. The explicit solvent model was adopted with a hybrid micro-solvation-continuum approach, to indicate the micro-solvation by explicit H2O molecules and the bulk solvation with ɛ = 27. The calculation results indicate that explicit H2O molecules participate in the reaction and catalytically promotes the proton transfer processes, suggesting that the explicit solvent model is preferable to the implicit solvent model to represent the conversion of 5-HMF in subcritical water. The isomerization of glucose to fructose is exothermic by 5.26 kcal/mol, where the isomerization of open-chain glucose to enol form is the rate-determining step, with the activation energy of 33.89 kcal/mol; the free energy of transition state configuration depends upon both the difficulty in α–H extraction of open-chain glucose and the stability of formed carbocation. In contrast, the hydration of fructose to 5-HMF is exothermic by 12.93 kcal/mol and the first hydration is the rate-determining step, with the activation energy of 50.59 kcal/mol; the free energy of transition state configuration is determined by the stability of carbocation formed by the dehydration of protonated OH group at C(2) site of fructose. This work discloses the promoting effect of Brønsted base on the isomerization of glucose to fructose and that of Brønsted acid on the dehydration of fructose to 5-HMF, which may provide certain clues to the modification of catalytic sites and the selection of solvent in the conversion of glucose to 5-HMF.

Few‐Unit‐Cell MFI Zeolite Synthesized using a Simple Di‐quaternary Ammonium Structure‐Directing Agent

AbstractSynthesis of a pentasil‐type zeolite with ultra‐small few‐unit‐cell crystalline domains, which we call FDP (few‐unit‐cell crystalline domain pentasil), is reported. FDP is made using bis‐1,5(tributyl ammonium) pentamethylene cations as structure directing agent (SDA). This di‐quaternary ammonium SDA combines butyl ammonium, in place of the one commonly used for MFI synthesis, propyl ammonium, and a five‐carbon nitrogen‐connecting chain, in place of the six‐carbon connecting chain SDAs that are known to fit well within the MFI pores. X‐ray diffraction analysis and electron microscopy imaging of FDP indicate ca. 10 nm crystalline domains organized in hierarchical micro‐/meso‐porous aggregates exhibiting mesoscopic order with an aggregate particle size up to ca. 5 μm. Al and Sn can be incorporated into the FDP zeolite framework to produce active and selective methanol‐to‐hydrocarbon and glucose isomerization catalysts, respectively.

Few-Unit-Cell MFI Zeolite Synthesized using a Simple Di-quaternary Ammonium Structure-Directing Agent.

Synthesis of a pentasil‐type zeolite with ultra‐small few‐unit‐cell crystalline domains, which we call FDP (few‐unit‐cell crystalline domain pentasil), is reported. FDP is made using bis‐1,5(tributyl ammonium) pentamethylene cations as structure directing agent (SDA). This di‐quaternary ammonium SDA combines butyl ammonium, in place of the one commonly used for MFI synthesis, propyl ammonium, and a five‐carbon nitrogen‐connecting chain, in place of the six‐carbon connecting chain SDAs that are known to fit well within the MFI pores. X‐ray diffraction analysis and electron microscopy imaging of FDP indicate ca. 10 nm crystalline domains organized in hierarchical micro‐/meso‐porous aggregates exhibiting mesoscopic order with an aggregate particle size up to ca. 5 μm. Al and Sn can be incorporated into the FDP zeolite framework to produce active and selective methanol‐to‐hydrocarbon and glucose isomerization catalysts, respectively.

High Selective Isomerization of Glucose to Fructose Catalyzed by Amidoximed Polyacrylonitrile.

The isomerization of glucose to fructose provides an important way to expand the utilization of biomass. Herein, an amidoximated polyacrylonitrile (PAO) with an amidoxime functional group was prepared and used as an active heterogeneous catalyst for the isomerization of glucose to fructose. The PAO was characterized by SEM, XPS, and FTIR. The yield of fructose reached 48.9% with a selectivity of 98.6% for a 5 h reaction in aqueous solution at an initial pH of 6.5 and 85 °C. The pH caused a great influence on the conversion of glucose and selectivity of fructose while a little effect on the yield of fructose in the range of pH 5–10. The activation energy of isomerization reaction was evaluated as 79.7 kJ·mol–1. The catalysis mechanism was proposed, and the synergistic effect of oxime and amino groups played an important role in the isomerization of glucose. PAO maintained good catalytic activity after four cycles.

Effect of silica source on the synthesis, property and catalytic performance of Sn-Beta zeolite

Sn-Beta zeolite is a promising heterogeneous Lewis acid catalyst. Hydrothermal synthesis of Sn-Beta(TEOS) using tetraethyl orthosilicate (TEOS) as silica source is a classical method. However, the hydrolysis of TEOS generates considerable ethanol, which is unfavorable for scalable production of Sn-Beta. Herein, cheap fumed silica and silica sol were used as Si sources to synthesize Sn-Beta and compared with that synthesized from TEOS. The crystalline phase, morphology, physicochemical properties, and the state of Sn were characterized. It was found that Sn-Beta can be successfully prepared with fumed silica and silica sol as well as TEOS as silica source. Sn was introduced into the framework of these samples. Sn-Beta synthesized from fumed silica (Sn-Beta(FS)) and silica sol (Sn-Beta(Sol)) had similar crystallization behavior and full crystallization time as well as morphology, crystal size with that from TEOS. Sn-Beta(Sol) has less silanols and lowest ratio of open/closed tin site among these samples. It exhibited higher catalytic activity for the conversion of glucose to methyl lactate and lower catalytic activity for the isomerization of glucose as compared with the other two samples. Sn-Beta(FS) showed similar catalytic performance in the studied reactions with Sn-Beta(TEOS).

Modification of commercial Y zeolites by alkaline-treatment for improved performance in the isomerization of glucose to fructose

• Alkaline-treatment of H-Y resulted in mesopores and tetrahedral extra-framework lewis acidic al. • Alkaline-treated H-Y yielded high isomerization selectivity and low side product formation. • Na-Y unaffected by alkaline-treatment maintaining low isomerization performance despite a high number of acidic sites. Isomerization of glucose to fructose is a key reaction step in the efficient production of valuable renewable chemical intermediates from biomass. Zeolites have been widely used to promote glucose isomerization, but only limited structure-activity relationship has been established and applied to optimize the reaction. In this work, commercial Y zeolites were modified by alkaline-treatment and their physicochemical properties and structures were correlated in order to optimize the catalytic performance for glucose isomerization. For H-Y, the alkaline-treatment developed new mesoporous structures with larger pore, modified the Si-O(H)-Al bonds and extracted silica from framework structures creating more tetrahedral extra-framework Lewis acidic aluminum. This increased the isomerization selectivity towards fructose more than twelve times and decreased significantly acetalization/ketalization side reactions compared to the pristine zeolite. In contrast, Na-Y contained mainly micropores and had less tetrahedral non-framework acidic Al-species, resulting in low glucose conversion and low fructose yield due to limited substrate accessibility to the pores, although the number of acid sites was tenfold higher than in H-Y. The study demonstrates how commercial Y zeolites can be designed by alkaline-treatment to comprise mesopores and weak acid sites, which greatly improve the catalytic performance for glucose isomerization to fructose.

Highly selective glucose isomerization by HY zeolite in gamma-butyrolactone/H2O system over fixed bed reactor

HZSM-5, Hβ, HY and USY zeolites were applied to the isomerization of glucose. An excellent selectivity (96%) of fructose was achieved, catalyzed by HY zeolite in gamma-butyrolactone/H2O over the fixed bed reactor. Moreover, the glucose isomerization could be carried out for over 480 h under the optimal conditions. High density of Lewis acid (0.27 mmol·g−1) over HY facilitates the intramolecular C2 → C1 H-shift reaction over the glucopyranose ring, which is the rate-determining step during Lewis acid-catalyzed steps of the glucose isomerization. Besides, large porous structure of HY zeolite (7.4 Å) facilitates the isomerization of glucose.

Systematic Modification of UiO‐66 Metal‐Organic Frameworks for Glucose Conversion into 5‐Hydroxymethyl Furfural in Water

AbstractMetal organic framework UiO‐66 is studied as an adaptable heterogeneous catalyst for glucose conversion. UiO‐66 was modified by; i) partial linker substitution, ii) particle size modulation and iii) linker defects. We studied the effect of crystallinity and functional groups on the glucose conversion and product yields. The main products are: i) fructose from the isomerisation of glucose, ii) mannose from the epimerisation of glucose and iii) 5‐hydroxymethyl furfural from the dehydration of fructose. We found that defective and nano crystalline UiO‐66 catalyst performs best for isomerisation. When 50 % of the linkers of UiO‐66 are replaced by a sulfonate‐containing linker, the catalyst shows higher isomerisation activity than other UiO‐66 catalysts. Naphthalene‐dicarboxylate linkers were introduced to induce hydrophobicity and this catalyst further increased isomerisation activity showing 31 % fructose selectivity. Finally, the promising catalysts were tested in a flow reactor and a bifunctional mixed linker catalyst possessing both hydrophobic and acidic functional groups is shown to be stable in a time‐on‐stream study.

Natural mineral bentonite as catalyst for efficient isomerization of biomass-derived glucose to fructose in water.

The development of inexpensive and efficient heterogeneous catalyst for the conversion of biomass including food and winery processing waste to value-added products is crucial in biorefinery. Glucose could be obtained via the hydrolysis of waste cellulose or starch-rich material, and the isomerization of glucose to fructose using either Lewis acid or Brønsted base catalysts is an important route in biorefinery. As a natural clay mineral, bentonite (Bt) is widely used as adsorption material and catalyst support, but how its intrinsic acid-base properties can impact the biomass conversion chemistry is still rarely reported. In this study, we investigated the influence of the textural and acid-base properties of Bt on the glucose isomerization reaction. The reaction kinetics and mechanism, and the effect of Al3+-exchange were explored. The results showed that the activation energy of Bt-catalyzed glucose conversion was 59.0kJmol-1, and the in-situ Fourier transform infrared spectrometer (FT-IR) characterization proved that Brønsted base was responsible for the isomerization. The highest fructose yield of 39.2% with 86.3% selectivity could be obtained at 110°C for 60min in water. Alkaline rinse and calcination can recover most of the catalytic activity of the spent catalyst.

Glucose isomerization catalyzed by swollen cellulose derived aluminum-hydrochar.

Since efficient isomerization of glucose to fructose is vital for valorizing cellulose fraction of biomass to value-added chemicals, an approach of engineering aluminum-hydrochar catalyst by impregnating aluminum on swollen cellulose derived hydrochar has been studied. The results showed that Al-hydrochar calcinated at 300°C achieved fructose yield of 26.3% in acetone/H2O reaction medium. It was found that the amorphous Al structures with nano-size on the surface of the carbon microspheres were the major contributor of the catalytic activity on glucose to fructose isomerization, while the formation of Al crystal had an inhibition effect on glucose isomerization. The deactivation study of Al-hydrochar catalysts showed the exfoliation of colloidal carbon containing aluminum active catalytic sites. This finding provides a novel strategy for efficient isomerization of glucose by Al-hydrochar prepared through hydrothermal carbonization and mild calcination activation process.

Kinetic insight into glucose conversion to 5-hydroxymethyl furfural and levulinic acid in LiCl⋅3H2O without additional catalyst

Conversion of glucose to 5-hydromethyl furfural (HMF) and levulinic acid (LA) was systematically investigated in LiCl·3H2O without additional catalyst. Based on the experimental investigations by using glucose, fructose and HMF as the reaction substrate separately, corresponding reaction kinetics in LiCl·3H2O were modelled by first-order assumption. Kinetic analysis demonstrates that high temperature favors the formation of LA, while low temperature facilitates to selectively form humins. To achieve high LA yield, at least a temperature of 140 °C is required. Without additional catalyst converting glucose to LA in LiCl·3H2O, humins was predominantly derived from glucose and HMF, and glucose isomerization is the reaction rate-determining step. The activation energies of the main reactions are 160.96 kJ/mol (glucose to HMF), 139.20 kJ/mol (fructose to HMF), and 71.81–76.48 kJ/mol (HMF to LA) respectively. The activation energies for humins formation were 23.45 kJ/mol from glucose, 49.54 kJ/mol from fructose, and 42.15–65.85 kJ/mol from HMF, respectively. It is verified that LiCl·3H2O, as compared to aqueous medium, is an excellent reaction medium for converting glucose to LA as it can provide the active centers for fructose to HMF reaction and HMF to LA reaction, but lack of highly efficient Lewis acid for glucose isomerization. With the addition of Lewis acid (such as AlCl3 and FeCl3), as high as 83.4% of LA yield can be obtained respectively when directly converting glucose, with the total selectivities of LA and HMF of 95%.