Catalytic Conversion Of Fructose Research Articles

Boosting Catalytic Performance of Amberlyst-15 by Modulating Surface Properties for Synthesis of 5-Hydroxymethylfurfural from High-concentration Fructose

The large-scale production of 5-hydroxymethylfurfural (HMF), a “sleeping giant” in sustainable chemistry, is frequently hampered by the severe formation of humins during the acid-catalyzed dehydration of high-concentration fructose. In this work, we demonstrate that the HMF yield could be remarkably enhanced by boosting the catalytic performance of a commercially used Amberlyst-15 solid acid organocatalyst, wherein the formation of humins could be effectively inhibited. We show that the modification of Amberlyst-15 with a typical cationic surfactant (i.e., cetyltrimethylammonium bromide (CTAB)) via charge interaction between sulfonic acid groups and quaternary ammonium cations led to an improved surface hydrophobicity and a reduced Brønsted acid density on the modified catalyst, thereby contributing to a complete suppression of HMF rehydration and remarkable suppression of humin formation via paths of both etherification-dehydration-condensation and degradative-condensation of fructose and/or HMF. As a result, the catalytic conversion of fructose over the CTAB-modified Amberlyst-15 catalyst in a low-boiling mixed solvent composed of 1,4-dioxane and H2O at 140oC within 2h led to high HMF yields in range of 53.3 ~ 63.1mol% in converting high-concentration fructose (10.0 ~ 50.0wt%), wherein an average enhancement of 20mol% in product yield was achieved when compared with that over un-modified Amberlyst-15. Moreover, the adsorption of humins on solid catalyst was significantly reduced due to the enhanced surface hydrophobicity and alleviated formation of humins, which accounted for a stable catalytic performance of the modified Amberlyst-15 catalyst for at least five runs. This work highlights the rational adjustment of the surface wettability of a commercial solid acid catalyst to suppress the undesired humin formation for future HMF biorefinery.

Sn‐MFI and Fe‐MFI zeolites for fructose conversion to levulinic and lactic acids by the one‐pot method

AbstractThis paper presents the results of the use of MFI zeolite as a catalyst modified with tin and iron. Sn‐MFI and Fe‐MFI catalysts were obtained by ion exchange under hydrothermal conditions with and without ammonium exchange. Catalytic materials were characterized with the use of analytical techniques such as X‐ray diffraction (XRD), Brunauer–Emmett–Teller method (BET), diffuse reflectance spectroscopy in the ultraviolet‐visible range (DRS UV–visible), hydrogen temperature programmed reduction (H2‐TPR), or Fourier transform infrared (FTIR) spectroscopy. The one‐pot catalytic conversion of fructose was performed at 220 °C for 1–5 h. Based on the results, the influence of time and material selection on the products obtained can be seen. Lactic acid (LAC) was obtained with a yield of 68.7% (after 2 h) and levulinic acid (LA) with a yield of 70.9% (after 5 h) with the participation of MFI. In turn, formic acid with a yield of 28.5% (after 5 h) was obtained with the participation of Fe‐MFI.

CATALYTIC CONVERSION OF FRUCTOSE INTO 5-HYDROXYMETHYLFURFURAL BY USING Cr-MODIFIED KUNIPIA-F CLAY

Catalytic conversion of fructose into 5-hydroxymethylfurfural (HMF) is investigated in detail using chromium-exchanged Kunipia-F clay (K550-Cr-calcined at 550°C) using dimethylsulfoxide (DMSO) as the solvent. The as-synthesized catalyst is characterized using XRD, ICE-AES, BET, SEM, FTIR, and EDX. The clay catalysts are initially screened for fructose conversion and HMF yield and then K550-Cr, which shows the superior activity amongst the catalysts understudy, is chosen for further experiments. Various reaction parameters like reaction temperature and time, catalyst dosage, initial substrate concentration, and catalyst reusability are studied in detail. The maximum HMF yield obtained is about 89% at milder reaction conditions (130°C for 3 h). The most interesting result is that the catalyst can be recovered easily without any loss and reused four times without loss in activity (HMF yield after five cycles is 88%).

Selective synthesis of 5-hydroxymethylfurfural over natural rubber–derived carbon/silica nanocomposites with acid–base bifunctionality

5-Hydroxymethylfurfural (HMF) is an important platform molecule, derived from biomass-based carbohydrates, for the production of renewable fuel additives, liquid hydrocarbon fuels, biopolymers, and specialty chemicals. In this study, a mesoporous carbon/silica (MCS) nanocomposite, as catalyst support, was prepared using a nanocomposite of natural rubber (NR) and hexagonal mesoporous silica (HMS) as a precursor. To obtain a series of acidic, basic, and bifunctional acid-base catalysts, the MCS surface was modified using post-synthesis methods in which the carbon moieties were decorated with sulfonic acid groups, whereas the silica matrix surface was grafted with 3-aminopropyl groups. The resulting materials exhibited high surface area, large pore volume, and contain some oxygen-containing functional groups. Their acid-base properties were tunable by varying the content of sulfonic acid and aminopropyl groups. The HMF was synthesized by catalytic conversion of fructose and glucose in a biphasic medium. Fructose dehydration catalyzed by sulfonated MCS catalyst (MCS-SO3H) at 150 °C for 2 h yields 56% HMF at 81% conversion. For the glucose system, the Brønsted basic sites facilitated the glucose–fructose isomerization, however, it promoted the formation of undesired humins. The acid/base ratio of bifunctional MCS catalysts (MCS-SO3H-NH2) contributes to the HMF yield and selectivity. The HMF yield of 39.4% was obtained over the MCS-SO3H-NH2 catalyst with an acid/base ratio of 0.10 at 190 °C for 1 h. In both systems, the formation of levulinic acid, a byproduct of HMF hydrolysis, was suppressed due to the hydrophobicity of the MCS catalyst. These developed catalysts are promising for the synthesis of HMF from glucose, at high substrate concentration than those reported in the literature.

Catalytic conversion of fructose into 5-HMF under eco-friendly-biphasic process

One-pot conversion of fructose into valuable 5-hydroxymethyl-2-furaldehyde (5-HMF) was investigated under a deep eutectic solvent-biphasic system.

Structure‐Function Relationships in Fructose Dehydration to 5‐Hydroxymethylfurfural under Mild Conditions by Porous Ionic Crystals Constructed with Analogous Building Blocks

Abstract5‐Hydroxymethylfurfural (HMF) is an important bio‐based chemical, which has been recognized as a key platform chemical for furan‐based polymers, biomass‐derived fuels, fine chemicals, and pharmaceuticals. Catalytic conversion of fructose into HMF is an important reaction, and the development of an efficient heterogeneous catalysts with high selectivity towards HMF is highly desired. In this study, several porous ionic crystals with a Keggin‐type polyoxometalate [PW12O40]3− and a macrocation [Cr3O(OOCCH2CN)6(H2O)3]+ as building blocks are synthesized, and the structures are solved by single crystal X‐ray diffraction analysis. The catalytic activities are basically dependent on the porosity, and the compound with a mesopore (aperture: 3 nm×2 nm) showed the highest HMF yield (30 % at 353 K in methanol/toluene solvent).

Catalytic Conversion of Fructose and 5-Hydroxymethylfurfural into 2,5-Diformylfuran over SBA-15 Supported Ruthenium Catalysts

In this study, the mesporous SBA-15 was prepared and used to graft biimidazole groups, which were used to anchor Ru3+ to give rise to a new ruthenium catalyst (SBA-15-Biimidazole-Ru). The structure of the SBA-15-Biimidazole-Ru catalyst was well characterized and used for the aerobic oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-diformylfuran (DFF). Several important parameters were studied and found that the reaction solvent and oxygen pressure showed a crucial role in the activity of the as-prepared SBA-15-Biimidazole-Ru catalyst. HMF conversion of 96.9% and DFF yield of 88.7% were achieved after 11 h at 110 °C under 15 bar oxygen pressure. One important characteristic of the SBA-15-Biimidazole-Ru catalyst is that it was very stable without loss of its catalytic activity during the recycling experiments, which was due to the strong interaction between the Ru3+ and the Biimidazole groups on the surface of SBA-15. Finally, the direct conversion of fructose into DFF was also performed by the use of Amberlyst 15 and SBA-15-Biimidazole-Ru as two binary catalysts. The dehydration of fructose over Amberlyst 15 catalyst and the subsequent oxidation of HMF over SBA-15-Biimidazole-Ru catalyst afforded DFF with an overall yield of 72.4%.

The catalytic conversion of fructose into 5-hydroxymethylfurfural over acid-functionalized KIT-6, an ordered mesoporous silica

Well-ordered KIT-6 mesoporous silica was synthesized via a sol–gel process and functionalized with sulfonic acid groups. The catalyst was characterized using XRD, BET, TGA, SEM, TEM and pyridine FTIR spectroscopy techniques. The prepared catalyst was used to catalyze the conversion of fructose to 5-hydroxymethylfurfural (HMF) in DMSO. Various reaction parameters such as effect of reaction temperature, reaction time, catalyst loading, and solvent on HMF yield were investigated. A fructose conversion of 100% and 84.1% yield of HMF was obtained at 165°C after 30min in DMSO. The reaction is quite selective toward HMF. The catalyst was used several times without significantly losing its catalytic effect.

Catalytic Conversion of Fructose and 5-Hydroxymethylfurfural into 2,5-Furandicarboxylic Acid over a Recyclable Fe3O4–CoOx Magnetite Nanocatalyst

A nano-Fe3O4–CoOx catalyst was prepared via a simple wet impregnation method. The nano-Fe3O4–CoOx catalyst showed good catalytic performance for the conversion of 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid (FDCA) with t-BuOOH as the oxidant. Several important reaction parameters were explored, with the highest FDCA yield of 68.6% obtained from HMF after 15 h at a reaction temperature of 80 °C. One-pot conversion of fructose into FDCA was also successful via two steps. Catalytic conversion of fructose over Fe3O4@SiO2–SO3H yielded 93.1% HMF, which was oxidized in situ into FDCA with a yield of 59.8%. Furthermore, recycling of nano-Fe3O4–CoOx was accomplished with the help of a magnetic field. Nano-Fe3O4–CoOx showed high stability in the reaction process. The use of nonprecious metals and no requirement of a base additive made this method much more economical and environmentally friendly.

Application of Polymeric Ionic Liquids in the Catalytic Conversion of Fructose to Lactic Acid

Preparation of lactic acid via chemical transformation of carbohydrates requires rigorous reaction conditions, such as high concentrations of alkali, high temperature, etc. This paper reports the use of polymeric ionic liquids ([IMEP]Cl) as catalyst for the hydrothermal conversion of fructose to lactic acid; the main variables of the reaction, temperature, substrate concentration, as well as the relative amount of [IMEP]Cl and NaOH were optimized. Results showed that, at 100 °C, substrate concentration of 25 mmol/L, reaction time of 30 min, the highest yield of lactic acid was 65% with [IMEP]Cl and NaOH concentrations of 100 and 50 mmol/L respectively. This method reduces the reaction temperature and alkali concentration compared to traditional hydrothermal method, additionally it was found that [IMEP]Cl can be used during 5 catalytic cycles without losing its catalytic effect with a lactic acid yield of 55% in the 5th reuse cycle. This demonstrates that the use of polymer ionic liquids as catalysts has a better prospect for future developments. A possible reaction mechanism has been proposed, but further investigation is required.

Catalytic Conversion of Fructose, Glucose, and Sucrose to 5-(Hydroxymethyl)furfural and Levulinic and Formic Acids in γ-Valerolactone As a Green Solvent

The conversion of fructose, glucose, and sucrose to 5-(hydroxymethyl)furfural (HMF) and levulinic acid (LA)/formic acid (FA) was investigated in detail using sulfuric acid as the catalyst and γ-valerolactone (GVL) as a green solvent. The H2SO4/GVL/H2O system can be tuned to produce either HMF or LA/FA by changing the acid concentration and thus allowing selective switching between the products. Although the best yields of HMF were around 75%, the LA/FA yields ranged from 50% to 70%, depending on the structure of the carbohydrates and the reaction parameters, including temperature, acid, and carbohydrate concentrations. While the conversion of fructose is much faster than glucose, sucrose behaves like a 1:1 mixture of fructose and glucose, indicating facile hydrolysis of the glycosidic bond in sucrose. The mechanism of the conversion of glucose to HMF or LA/FA in GVL involves three intermediates: 1,6-anhydro-β-d-glucofuranose, 1,6-anhydro-β-d-glucopyranose, and levoglucosenone.

Catalytic conversion of fructose and sucrose to 5-hydroxymethylfurfural using simple ionic liquid/DMF binary reaction media

The production of 5-hydroxymethylfurfural (HMF) from carbohydrates has been reported intensively in recent years. HMF is believed to be a versatile platform chemical and the focus of synthesizing it has especially been on the development of efficient catalysts, such as Lewis and Brønsted Acids. On the contrary, herein, we report a novel catalytic system that consists of 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and N,N-Dimethylformamide (DMF) without any additional metal salts or acids, which leads to reasonable HMF yields (84.9%) and selectivities. In addition, the degradation mechanism of fructose catalyzed by [AMIM]Cl is also proposed in this communication.

Catalytic conversion of fructose into furans using FeCl3 as catalyst

Conversion of fructose into furan derivates 5-hydroxymethylfurfural (HMF) and 5-ethoxymethylfurfural (EMF) was performed in ethanol-[Bmim]Cl solvent systems, catalyzed by FeCl3. HMF was obtained in a high yield of 90.8% for 4h at 100°C in 1-butyl-3-methylimidazole chloride ([Bmim]Cl). The ratio of [Bmim]Cl to ethanol showed a remarkable effect on the yields of HMF and EMF. The maximum EMF yield of 30.1% was obtained in a mixed solvent of [Bmim]Cl (0.5g) and ethanol (4.5g). On the meanwhile, HMF was obtained in a yield of 60.3%.