Synthesis Of EMF Research Articles

Catalytic Conversion of 5-Hydroxymethylfurfural and Fructose to 5-Ethoxymethylfurfural over Sulfonated Biochar Catalysts

5-Hydroxymethylfurfural (HMF) is a key platform compound that can be produced by the dehydration of typical carbohydrates like glucose and fructose. Among the derivatives of HMF, 5-ethoxymethylfurfural (EMF) is the etherification product of HMF with ethanol. Owing to some advantages (i.e., high energy density), EMF has been regarded as a potential liquid fuel. Therefore, catalytic conversion of HMF and fructose to EMF is of significance, especially using heterogeneous catalysts. In this paper, we demonstrated the preparation of biomass-based catalysts for the synthesis of EMF from HMF and fructose. Some sulfonated biochar catalysts were prepared by the carbonization of biomass-based precursors at high temperature in N2, followed by the subsequent sulfonation process employing concentered H2SO4 as sulfonation reagent. The obtained catalysts were characterized by scanning electron microscope (SEM), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), and element analysis. The catalytic conversion of HMF to EMF was carried out in ethanol, providing a 78% yield with complete conversion at 120 °C. The catalytic activity of the used catalyst showed slight decrease for the etherification of HMF. Moreover, the catalysts were effective for the direct conversion of fructose towards EMF in 64.9% yield. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Selective transformation of carbohydrates to 5-ethoxymethylfurfural over tungstophosphoric acid supported on activated carbon derived from orange peel

A series of tungstophosphoric acid supported on activated carbon derived from left-over orange-peel catalysts (TPA/OAC) have been prepared. These catalysts were examined for one-pot catalytic transformation of fructose/glucose to 5-ethoxymethylfurfural. Physico-chemical properties of the catalytic materials were executed by using various characterization methods. Spectroscopic analysis results propose that TPA was finely distributed on the high surface area carbon support with persistent Keggin ion structure. The EMF yield is depended on the content of active component TPA on support and also on the reaction conditions. The catalyst with 25 wt% TPA on OAC presented highest activity towards EMF synthesis from fructose. Although, the catalyst 25 wt% TPA/OAC showed low activity towards EMF synthesis from glucose, higher yields of ethyl glucopyranoside could be formed from glucose in EtOH. Activated carbon was synthesized by carbonization of orange peel treated with H3PO4, which was used as a good support for HPAs. The catalysts are quite stable and recyclable for the dehydrative alkylation of fructose.

Ethanolysis of glucose into biofuel 5-ethoxymethyl-furfural catalyzed by NH4H2PO4 modified USY zeolite

5-Ethoxymethylfurfural (EMF) can be considered as a potential biofuel because of its excellent combustion properties, such as high energy density and low carbon smoke emissions. In this study, Ultra-stable Y (USY) zeolite was modified with NH4H2PO4 and then used as an efficient solid catalyst for the catalytic synthesis of EMF via ethanolysis of glucose First, the NH4H2PO4-modified USY was characterized by FT-IR, XRD, BET, and NH3-TPD. The effect of reaction temperature, reaction time, substrate concentration, and catalyst loading on the yield of EMF was investigated. The P0.2-USY optimal EMF yield was 39.6 mol%, which increased by 20.7% compared to USY, and still had better activity after being reused for 5 cycles. Moreover, the pseudo-homogeneous first-order kinetics model was developed to elucidate the kinetics of EMF formation from glucose, and the kinetics results showed that the activation energy of EMF formation (64.2 kJ⋅mol-1) was lower than that of humins formation (73.2 kJ⋅mol-1). Finally, the ethanolysis pathway was proposed based on the product distribution.

Synthesis of 5‐ethoxymethylfurfural from glucose catalyzed by porous tetra‐component metal oxides solid acid

AbstractThe production of 5‐ethoxymethylfurfural (EMF) from cheap and abundant glucose feedstock has attracted a great deal of attention because of its potential applications. Herein, three porous tetra‐component metal oxide solid acid catalysts (SO42−/ZFSA‐A, SO42−/ZFSA‐F‐10, SO42−/ZFSA‐F‐20) containing both Brønsted and Lewis acid sites have been successfully synthesized and can efficiently catalyze the synthesis of EMF from glucose. Particularly, the SO42−/ZFSA‐A, SO42−/ZFSA‐F‐10, and SO42−/ZFSA‐F‐20 catalysts were prepared under the template of sodium alginate, 10% F127, and 20% F127, respectively. The prepared catalysts were characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), N2‐adsorption–desorption isotherm, X‐ray photoelectron spectroscopy (XPS), thermogravimetry (TG), temperature‐programmed desorption of ammonia (NH3‐TPD), and pyridine infrared spectra (Py‐FTIR). The characterization results indicated that all three catalysts have a porous structure. The pore distribution of the SO42−/ZFSA‐A catalyst is mainly macroporous and mesoporous, while the SO42−/ZFSA‐F‐10 and SO42−/ZFSA‐F‐20 catalysts are mainly mesoporous. The SO42−/ZFSA‐F‐20 catalyst exhibited the highest catalytic performance due to its large specific surface area, desirable mesoporous structure, high total acidity (especially strong and super strong acidity), and appropriate Lewis/Brønsted acid ratio. By applying SO42−/ZFSA‐F‐20, the formation of EMF from glucose was successfully catalyzed and EMF was obtained at a yield of 34.56% after 12 h at 160°C. This yield is much higher compared with most other results achieved by solid acids catalysis. In addition, the reaction parameters such as reaction temperature, reaction time, glucose amount, and catalyst dosage were shown to have a significant effect on the catalytic performance. Notably, the SO42−/ZFSA‐F‐20 catalyst exhibited good reusability, as its activity did not significantly diminish after four rounds of repeated experiments and was successfully reactivated after calcination.

DFT and dynamic analysis of glucose alcoholysis conversion to 5-ethoxymethylfurfural and ethyl levulinate

An effective catalytic strategy for the conversion of glucose to 5-ethoxymethylfurfural (EMF) catalyzed by ultrastable Y zeolite (USY) in a co-solvent system was developed. Effects of co-solvent and reaction conditions were first investigated. Tetrahydrofuran (THF) with low dipolarity/polarizability (π*) was screened as the appropriate co-solvent, and a higher EMF yield of 41.46% was obtained as the ratio of ethanol to THF was 7:3. The macroscopic reaction kinetic study indicated that THF can protect EMF from easy degradation to EL. Moreover, the reusability and the characterization of USY verified the feasibility of USY as an efficient solid acid catalyst. In this study, density functional theory (DFT) calculations for the catalytic mechanism and solvent effect at the molecular scale were performed for the first time. The extra-framework aluminum species (EFAL), in which Al3+ played an essential role in the reaction as the preferred EFAL species, and THF can reduce the energy barrier of USY-catalyzed glucose isomerization. Meanwhile, the inhibitory effect of THF on EMF alcoholysis was explored via the frontier molecular orbital theory. The results showed that THF increased the LUMO energy of EMF compared with ethanol and γ-valerolactone, which decreased its susceptibility to nucleophilic attack and reduced the adverse alcoholysis of EMF and humins formation. This study provided an enlightening reference for the efficient synthesis of EMF from carbohydrates catalyzed by solid acid catalyst under solvent effect.

Sulfonic acid-functionalized PCP(Cr) catalysts with Cr3+ and -SO3H sites for 5-ethoxymethylfurfural production from glucose.

5-Ethoxymethylfurfural (EMF) has been identified as a potential biofuel and fuel additive, for which the production from glucose (the most abundant and inexpensive monosaccharide) in a one-step process would be highly desirable. Here, the synthesis of sulfonic acid-functionalized porous coordination polymers (PCPs) and their application as catalysts for EMF synthesis are reported. PCP(Cr)-BA (PCP material with Cr3+ ions and H2BDC-SO3H linkers) and PCP(Cr)-NA (PCP material with Cr3+ ions and H2NDC(SO3H)2 linkers) materials containing both Cr3+ sites and Brønsted-acidic –SO3H sites were prepared. The morphology, pore structure, acidity, chemical composition, and thermal stability of the two functionalized PCP(Cr) catalysts were analyzed by systematic characterization. The catalysts featured a porous morphology and dual Cr3+ and –SO3H sites, which enabled the cascade conversion of glucose to EMF. PCP(Cr)-BA exhibited higher performance than PCP(Cr)-NA with an EMF yield of 23.1% in the conversion of glucose at 140 °C after 22 h in an ethanol/water system. In addition, the as-prepared catalyst exhibited a high stability in the current catalytic system for EMF production from glucose with a constant catalytic activity in a four-run recycling test without an intermediate regeneration step.

Catalytic Valorization of Expired Fructan-Rich Food into the Biofuel 5-Ethoxymethylfurfural via a Restaurant Food Waste-Derived Carbonaceous Solid Acid

Valorization of food waste into value-added fuels or chemicals is of considerable significance. Herein, an efficient catalytic approach was developed for transforming expired fructan-rich food (probiotics beverage powder, onion powder and garlic powder that have expired) into the biofuel, 5-ethoxymethylfurfural (EMF), via a carbonaceous solid acid synthesized by hydrothermal carbonization and sulfonation of restaurant food waste. The as-prepared restaurant food waste-derived carbonaceous solid acid catalyst (FW-SO3H) was well-characterized by a series of model physical and chemical technologies, and its catalytic performances were evaluated by the ethanolysis of expired fructan-rich food for EMF synthesis. The effects of reaction process variables were investigated. A considerable EMF yield of 52.1% from expired probiotics beverage powder was obtained in DMSO/ethanol medium at 140 °C for 4 h. EMF yields of 20.4% and 11.7% were achieved from expired onion powder and expired garlic powder, respectively. This work provides a valorization strategy for both expired fructan-rich food and restaurant food waste.

A facile way for sugar transformation catalyzed by carbon-based Lewis-Brønsted solid acid

In this work, catalytic transformation of sugar into 2-Formyl-5-ethoxymethylfuran (EMF) was studied using Zn-trapped sulfonated carbon (SO3H-Zn-SC) catalyst. The catalyst was easily prepared via impregnation-pyrolysis and sulfonation. The physical and chemical properties of as-prepared catalyst were tested and discussed in details. For upgrading experiment, EMF synthesis from glucose transformation via isomerization, dehydration and etherification processes was performed using ultrasonic system. The increasing of ultrasonic power and ultrasonic duty cycle promoted the formation of EMF product, providing a maximum EMF yield of 97.8%. The ultrasonic application promoted the selectivity for EMF formation at shorter-faster reaction rate. Moreover, SO3H-Zn-SC also exhibited good reusability with low amount of acid leaching in each cycle. This research provided alternative way for improving the yield of EMF at short reaction time.

Fully catalytic upgrading synthesis of 5-Ethoxymethylfurfural from biomass-derived 5-Hydroxymethylfurfural over recyclable layered-niobium-molybdate solid acid

Biomass-derived resources exploited in depth toward the synthesis of high value-added chemicals is very promising, but still limited by the applicable catalyst. In this paper, we report regulated robust multilayer-like polyoxometalates(Niobium molybdate) specific to the catalytic synthesis of promising 5-Ethoxymethylfurfural (EMF). The present solid acid catalysts resulted from precisely-tuned compositions of Nb and Mo toward acquiring controlled Brønsted acid amounts and interlayer space coupling with specific Lewis acid sites are demonstrated to be the determining factors for tuning conversion and selectivity in the synthesis of EMF, respectively. The characterization results indicate that the increment in Nb moiety is beneficial to produce more accessible acid sites and the enlarged interlayer space in the catalyst, thereby promoting the acid-catalyzed conversion. As a result, the full conversion(Conv. 100%) of 5-hydroxymethylfurfural into the 5-Ethoxymethylfurfural (Select. >99%) by etherification with ethanol within only 60 min was realized as the record-high yield under the solvent-free condition, far outperforming several traditional catalysts. In addition, the rational 67% yield of EMF was received when using fructose as an initial reactant. Ulteriorly, the resultant catalyst inherits the superior catalytic activity in the substrate expansion experiments in the presence of different alcohols. More importantly, the resulted catalyst shows durable catalytic activity without any activity-loss during the eight recycling, which reveals the huge potential industrial application prospect.

Upgrading of Carbohydrates to the Biofuel Candidate 5-Ethoxymethylfurfural (EMF)

5-Ethoxymethylfurfural (EMF), one of the significant platform molecular derivatives, is regarded as a promising biofuel and additive for diesel, owing to its high energy density (8.7 kWh·L−1). Several catalytic materials have been developed for the synthesis of EMF derived from different feedstocks under relatively mild reaction conditions. Although a great quantity of research has been conducted over the past decades, the unsatisfactory production selectivity mostly limited to the range 50%–70%, and the classic fructose used as the substrate restricted its application for fuel manufacture in large scale. To address these production improvements, this review pays attention to evaluate the activity of various catalysts (e.g., mineral salts, zeolites, heteropolyacid-based hybrids, sulfonic acid-functionalized materials, and ionic liquids), providing potential research directions for the design of novel catalysts for the achievement of further improved EMF yields.

Fabrication of biobased heterogeneous solid Brønsted acid catalysts and their application on the synthesis of liquid biofuel 5-ethoxymethylfurfural from fructose

A series of biobased heterogeneous solid Brønsted acid catalysts with perfect spherical microstructures are successfully fabricated directly from waste Camellia oleifera shells by a simple hydrothermal carbonization-annealing-sulfonation process. 350 °C low temperature annealing process helps to increase the activity of the catalyst due to the simultaneous maintenance of the spherical microstructure and aromatic carbon framework. As a renewable catalyst with low cost, the as-prepared materials are successfully applied on the synthesis of green renewable liquid biofuel 5-ethoxymethylfurfural (EMF) directly from fructose. In the catalytic test, the influences of reaction time and temperature, fructose concentration, and adding amount of the catalyst on the yield of EMF are investigated systematically. As a result, the optimal reaction temperature is 100 °C, the EMF yield monotonically increases with prolonging the reaction time from 3 to 24 h, the optimal fructose concentration is 0.5 mmol, and the EMF yield gradually increases with increasing the adding amount of the catalyst from 50 to 150 mg. In addition, the as-prepared catalysts exhibit considerably high stability in the current EMF synthesis system, and they can maintain a similar level of reactivity after four catalytic cycles.

Insights into the Metal Salt Catalyzed 5-Ethoxymethylfurfural Synthesis from Carbohydrates

The use of common metal salts as catalysts for 5-ethoxymethylfurfural (EMF) synthesis from carbohydrate transformation was performed. Initial screening suggested AlCl3 as an efficient catalyst for EMF synthesis (45.0%) from fructose at 140 °C. Interestingly, CuSO4 and Fe2(SO4)3 were found to yield comparable EMF at lower temperature of 110 to 120 °C, and high yields of ethyl levulinate (65.4–71.8%) were obtained at 150 °C. However, these sulfate salts were inactive in EMF synthesis from glucose and the major product was ethyl glucoside with around 80% yield, whereas EMF of 15.2% yield could be produced from glucose using CrCl3. The conversion of sucrose followed the accumulation of the reaction pathways of fructose and glucose, and a moderate yield of EMF could be achieved.

Direct Conversion of Carbohydrates into 5‐Ethoxymethylfurfural (EMF) and 5‐Hydroxymethylfurfural (HMF) catalyzed by Oxomolybdenum complexes

AbstractThis work reports the first methodology for one‐pot synthesis of 5‐ethoxymethylfurfural (EMF) and 5‐hydroxymethylfurfural (HMF) from various carbohydrates catalyzed by oxo‐molybdenum complexes. The best results of EMF (53‐60 %) were obtained using a mixture of ethanol/THF (5:2) catalyzed by MoO2Cl2(H2O)2 at 120 °C, after 17 h. This dioxo‐molybdenum complex also promoted the synthesis of EMF from other carbohydrates such as inulin and sucrose. The selective conversion of fructose into HMF was achieved in good yield (75 %) from fructose using MoO2Cl2(H2O)2 in DMSO at 120 °C after 30 minutes. This novel methodology has the advantages of using an inexpensive, environmental friendly and air stable catalyst with an easy preparation.

Fabrication of −SO3H functionalized aromatic carbon microspheres directly from waste Camellia oleifera shells and their application on heterogeneous acid catalysis

Sulfonic acid groups functionalized aromatic carbon microspheres (Ar-CMSs–SO3H) were first successfully fabricated directly from waste Camellia oleifera shells by simple steps in the assistance of phloroglucinol. As a heterogeneous solid Brønsted acid catalyst, the as-prepared Ar-CMSs–SO3H showed considerably high activity because of its numerous spherical microstructure and abundant surface sulfonic acid groups (–SO3H). Subsequently, the as-prepared Ar-CMSs–SO3H was applied to the synthesis of biofuels 5-ethoxymethylfurfural (EMF) from biological platform compounds 5-hydroxymethylfurfural (HMF). The catalytic results showed that both sulfonation conditions in the course of Ar-CMSs–SO3H preparation and catalytic reaction conditions in the course of EMF synthesis had a significant effect on the EMF yield and HMF conversion rate.

Magnetically-recoverable carbonaceous material: An efficient catalyst for the synthesis of 5-hydroxymethylfurfural and 5-ethoxymethylfurfural from carbohydrates

A novel, magnetically recoverable carbonaceous solid acid Fe3O4@C-SO3H catalyst for the conversion of carbohydrates to 5-ethoxymethylfurfural (EMF) was developed. The effect of the DMSO fraction in the ethanol-DMSO binary solvent on the distribution of the reaction products was investigated. The catalyst showed an excellent activity in the synthesis of EMF from fructose and 5-hydroxymethylfurfural (HMF). 5- Ethoxymethylfurfural was also obtained with a high yield of 64.2% in an ethanol–DMSO solvent system via one-step conversion of fructose. After reaction, the catalyst could be recovered by exposure of the reaction mixture to external magnetic field and reused several times without a loss of catalytic activity.

Method for restoring activity to a spent hydroprocessing catalyst, a spent hydroprocessing catalyst having restored catalytic activity, and a hyrdoprocessing process

In this study, we have developed an effective method for the conversion of carbohydrates into liquid biofuels 5-ethoxymethylfurfural (EMF) over a magnetic solid acid catalyst (Fe3O4@CSO3H). The as-prepared magnetic Fe3O4@CSO3H catalyst showed high catalytic activity toward the synthesis of EMF from carbohydrates. The etherification of 5-hydroxymethylfurfural (HMF) with ethanol over Fe3O4@CSO3H catalyst produced EMF with a high yield of 88.4%. The Fe3O4@CSO3H catalyst also showed high activity toward the one-pot conversion of fructose based carbohydrates into EMF. EMF was obtained in a yield of 67.8% from fructose, and that was 58.4% from inulin. The Fe3O4@CSO3H catalyst could be easily collected by an external magnet and reused for several times without the significant loss of its catalytic activity.

Efficient synthesis of promising liquid fuels 5-ethoxymethylfurfural from carbohydrates

In this study, we have developed an effective method for the conversion of carbohydrates into liquid biofuels 5-ethoxymethylfurfural (EMF) over a magnetic solid acid catalyst (Fe3O4@CSO3H). The as-prepared magnetic Fe3O4@CSO3H catalyst showed high catalytic activity toward the synthesis of EMF from carbohydrates. The etherification of 5-hydroxymethylfurfural (HMF) with ethanol over Fe3O4@CSO3H catalyst produced EMF with a high yield of 88.4%. The Fe3O4@CSO3H catalyst also showed high activity toward the one-pot conversion of fructose based carbohydrates into EMF. EMF was obtained in a yield of 67.8% from fructose, and that was 58.4% from inulin. The Fe3O4@CSO3H catalyst could be easily collected by an external magnet and reused for several times without the significant loss of its catalytic activity.

Direct catalytic transformation of carbohydrates into 5-ethoxymethylfurfural with acid–base bifunctional hybrid nanospheres

A series of acid–base bifunctional hybrid nanospheres prepared from the self-assembly of basic amino acids and phosphotungstic acid (HPA) with different molar ratios were employed as efficient and recyclable catalysts for synthesis of liquid biofuel 5-ethoxymethylfurfural (EMF) from various carbohydrates. A high EMF yield of 76.6%, 58.5%, 42.4%, and 36.5% could be achieved, when fructose, inulin, sorbose, and sucrose were used as starting materials, respectively. Although, the acid–base bifunctional nanocatalysts were inert for synthesis of EMF from glucose based carbohydrates, ethyl glucopyranoside in good yields could be obtained from glucose in ethanol. Moreover, the nanocatalyst functionalized with acid and basic sites was able to be reused several times with no significant loss in catalytic activity.

Synthesis of furan compounds from HMF and fructose catalyzed by aluminum-exchanged K-10 clay

K-10 clay-Al was found to be effective for the synthesis of 5-ethoxymethylfurfural (EMF) from 5-hydroxymethylfurfural (HMF) with a yield of 89.5%. Further synthesis of EMF from the one-pot conversion of fructose in ethanol was failed, but ethyl fructoside was produced. When the conversion of fructose was carried out in DMSO, HMF was obtained in a high yield of 93.2%.

Efficient one-pot synthesis of 5-ethoxymethylfurfural from fructose catalyzed by heteropolyacid supported on K-10 clay

Synthesis of 5-ethoxymethylfurfural (EMF) from the etherification of 5-hydroxymethylfurfural (HMF) and the dehydrative etherification of fructose over K-10 clay supported dodecatungstophosphoric acid (abbreviated as K-10 clay-HPW). 30%wt.% K-10 clay-HPW was found to be the efficient and robust catalyst for the synthesis of EMF. The highest EMF yield of 91.5% was obtained from HMF after 10h at 100°C. Further more, the catalyst also showed high catalytic activity for the dehydrative etherification of fructose with EMF yield of 61.5%. The reaction work-up is very simple and the catalyst could be reused several times without the significant loss of its catalytic activity.