Biomass-derived Carbohydrates Research Articles

Regiodivergent Functionalization of Protected and Unprotected Carbohydrates using Photoactive 4-Tetrafluoropyridinylthio Fragment as an Adaptive Activating Group.

The selective functionalization of carbohydrates holds a central position in synthetic carbohydrate chemistry, driving the ongoing quest for ideal approaches to manipulate these compounds. In this study, we introduce a general strategy that enables the regiodivergent functionalization of saccharides. The use of electron-deficient photoactive 4-tetrafluoropyridinylthio (SPyf) fragment as an adaptable activating group, facilitated efficient functionalization across all saccharide sites. More importantly, this activating group can be directly installed at the C1, C5 and C6 positions of biomass-derived carbohydrates in a single step and in a site-selective manner, allowing for the efficient and precision-oriented modification of unprotected saccharides and glycans.

Tandem catalytic conversion of glucose and cellobiose to 5-ethoxymethylfurfural with record yields

The conversion of biomass-derived carbohydrates to 5-ethoxymethylfurfural (EMF) is a fascinating reaction with 100% carbon atom utilization. Although effective conversion of 5-hydroxymethylfurfural (HMF) and fructose to EMF have been achieved, the direct conversion of glucose only gave low EMF yields. Herein, we reveal that the combinations of common Lewis acid with Brønsted acid in ethanol universally catalyze rapid etherification of glucose to intractable ethyl glucoside (EGL), as impedes the further conversion toward the desired products. The synergy of large-pore tin phosphate (SnPO) bearing strong Lewis acidic sites with acidic ionic liquid 1-(4-sulfobutyl)-3-methylimidazolium chloride (BSO3HMIMCl) enable tandem catalytic conversion of glucose, cellobiose and starch to EMF with record yields (61.7%, 61.8% and 55.7%, respectively), far exceeding previous reports. This transformation probably occurs via multiple parallel pathways, where water molecules generated by dehydration cooperate with acid and Cl- to hydrolyze EGL back to glucose, thus forming a positive feedback on EMF production.

Biomass-Derived Carbohydrates to 5-Ethoxymethylfurfural

Biomass-Derived Carbohydrates to 5-Ethoxymethylfurfural

Conversion of biomass-derived carbohydrates into 5-hydroxymethylfurfural over sulfonated zirconium/tin mixed-metal metal–organic frameworks in deep eutectic solvents-water based biphasic system

5-hydroxymethylfurfural (5-HMF) is a key platform chemical that can be applied to generate varied value-added products. Herein, the sulfonated zirconium/tin Mixed-Metal metal–organic frameworks (MOFs), Sn/UiO-66-SO3H catalysts were employed for catalytic conversion of biomass-derived carbohydrates (glucose, sucrose, maltose, starch, and cellulose) to 5-HMF in green deep eutectic solvents (DESs)-water based biphasic system. The Sn/UiO-66-SO3H catalysts were prepared by infiltrating Sn4+ into the UiO-66-SO3H via post-synthesis modification. The synthesized catalysts were characterized by PXRD, SEM, FTIR, N2 adsorption–desorption analysis, XPS, ICP-OES, NH3-TPD and Py-FTIR. The synergistic effect of Zr4+ and Sn4+ increased the total acidity and pore size of MOFs, thus promoting the catalytic performance of MOFs towards carbohydrates conversion to 5-HMF. The 24-Sn/UiO-66-SO3H with impregnation of Sn4+ for 24 h presented desired catalytic ability, which resulted in 81.5 % and 41.7 % 5-HMF yields from glucose and cellulose in DES betaine-malic acid–water/MIBK biphasic system, respectively. Moreover, the five-recycling test for 24-Sn/UiO-66-SO3H demonstrated excellent reusability of the prepared catalyst. This study offered a novel sulfonated Mixed-Metal strategy on MOFs in DES betaine-malic acid–water based biphasic system for the production of 5-HMF from biomass-derived carbohydrates.

Optimizing 5-hydroxymethylfurfural production from biomass carbohydrates: ionic liquid-catalyzed pathways in deep eutectic solvents under sonication and thermal conditions

The synthesis of ionic liquid (IL)-based mesopore SBA-16 catalyst for the conversion of biomass-derived carbohydrates into 5-hydroxymethylfurfural (5-HMF) in the presence of 15 deep eutectic solvents (DESs) under sonication and thermal conditions.

Incorporation of tin oxide nanoparticles on sulfonated carbon microspheres as a bifunctional catalyst for efficient conversion of biomass-derived monosaccharides to 5-Hydroxymethylfurfural and furfural

Effective production of versatile platform molecules 5-Hydroxymethylfurfural (HMF) and furfural (FF) from biomass-derived carbohydrates is of great importance to synthesis of high-value-added bio-based chemicals and fuels. In order to highly efficient synthesis of HMF and FF, in this work, by integrating tin oxide nanoparticles with sulfonated carbon microspheres, a novel solid acid catalyst (SnOx-NPs@SC) with tunable Lewis/Brønsted acidity was developed for the conversion of glucose and xylose to HMF and FF, respectively. Characterization and experiment revealed that optimization of Sn precursor dosage and pyrolysis temperature was beneficial to the integration of SnOx with sulfonated carbon microspheres and formation of appropriate acid strength and balanced Lewis/Brønsted acid, which could enhance the selective conversion of glucose and xylose to HMF and FF. In the H2O/THF biphasic solvent system with 1.5 mol/L NaCl, the optimized catalyst (0.35-SnOx-NPs@SC-500) exhibited excellent catalytic performance by achieving 90.2% selectivity of HMF at 180 ℃ for 2 h and 85.4% selectivity of FF at 170 ℃ for 2 h, and displayed relatively high stability in five consecutive experimental cycles. The mechanism was discussed based on the physicochemical properties of the catalyst and reaction system. The results of this work provide an effective strategy for designing a bifunctional solid acid catalyst for the one-pot production of highly value-added biomass intermediates.

Sustainable production of value-added <italic>N</italic>-heterocycles from biomass-derived carbohydrates via spontaneous self-engineering

Sustainable production of value-added <italic>N</italic>-heterocycles from biomass-derived carbohydrates via spontaneous self-engineering

Integrating Fermentation Engineering and Organopalladium Chemocatalysis for the Production of Squalene from Biomass-Derived Carbohydrates as the Starting Material

The transition from fossil resources to renewable biomass for the production of valuable chemicals and biobased fuels is a crucial step towards carbon neutrality. Squalene, a valuable chemical extensively used in the energy, healthcare, and pharmaceutical fields, has traditionally been isolated from the liver oils of deep-sea sharks and plant seed oils. In this study, a biochemical synergistic conversion strategy was designed and realized to convert glucose to squalene by combining fermentation technology in yeast with reductive coupling treatment of dienes. First, glucose derived from hydrolysis of cellulose was used as a renewable resource, using genetically engineered Saccharomyces cerevisiae as the initial biocatalyst to produce β-farnesene with a titer of 27.6 g/L in a 2.5 L bioreactor. Subsequently, intermediate β-farnesene was successfully converted to squalene through the organopalladium-catalyzed reductive coupling reaction involving the formation of Pd(0)L2 species. Under mild reaction conditions, impressive β-farnesene conversion (99%) and squalene selectivity (100%) were achieved over the Pd(acac)2 catalyst at a temperature of 75 °C in an ethanol solvent after 5 h. This advancement may provide insights into broadening squalene production channels and accessing the complex skeletons of natural terpenoids from biorenewable carbon sources, offering practical significance and economic benefits.

Direct Catalytic Conversion of Biomass-derived Carbohydrates to Ethyl Levulinate

Abstract: Recently, levulinic acid as an important bio-based platform compound has attracted wide attention, and its potential application value is very high. This article focuses on chem-catalytic produced ethyl levulinate (EL) from biomass-derived carbohydrates (C6 carbohydrates) via multiple reaction pathways, which has an energy density comparable to gasoline and has great potential as a fuel additive. This review focuses on recent examples of the synthesis of EL from various materials using homogenous or heterogeneous catalysts. Special emphasis is placed on the understanding of the reaction mechanism and pathways. This review also summarizes the future opportunities and challenges associated with the applications of EL as a fuel additive and in other fields.

Catalytic aerobic oxidation of carbohydrates to formic acid over H5PV2Mo10O40: Rate relationships among catalyst reduction, catalyst re-oxidation and acid-catalyzed reactions and evidence for the Mars-van Krevelen mechanism

Catalytic aerobic oxidation of biomass-derived carbohydrates is a promising way to sustainably produce formic acid. Understanding the rate relationships among catalyst reduction, catalyst re-oxidation and acid-catalyzed reactions occurring in catalytic systems is significant for the revelation of catalytic mechanism and the selection of reaction conditions. Herein, the rate relationships among the multiple reactions over an excellent homogeneous catalyst, H5PV2Mo10O40 (HPA-2) were investigated. A rate matching relationship between catalyst reduction and catalyst re-oxidation was unveiled by the separate redox kinetics of catalyst, indicating that higher O2 pressures are required to maintain the activity of HPA-2 at higher temperatures. The consistency between the separate redox kinetics and the catalytic oxidation provided the first kinetic evidence of the Mars-van Krevelen mechanism for catalytic oxidation of carbohydrates. Furthermore, rate relationships among the multiple reactions at different conditions were discussed to clarify the correlation between product selectivity and reaction conditions.

Novel insights into CO2 inhibition with additives in catalytic aerobic oxidation of biomass-derived carbohydrates to formic acid

Formic acid (FA) is considered an ideal energy carrier for hydrogen. Catalytic aerobic oxidation of biomass-derived carbohydrates is a promising method to produce renewable FA. Interestingly, the addition of some low-carbon alcohols or dimethyl sulfoxide remarkably improved FA selectivity in the popular vanadium-based catalytic system. This work unveils an advanced mechanism of the product improvement with additives. Control experiments of vanadium-substituted heteropolyacids (HPA-n) in different redox states and ESR spectroscopy verified that hydroxyl radicals were formed in the re-oxidation of reduced HPA-n. Different-type oxidations and model reactions revealed that the hydroxyl radicals caused overoxidation by oxidizing aldehydic groups to carboxylic groups as the precursors of CO2. The additives scavenged hydroxyl radicals so glucose was oxidized into FA with high selectivity. Furthermore, the hydroxyl radicals were quantified and the effect of isopropanol dosage on glucose oxidation was investigated. The CO2-inhibition effect of isopropanol was also exhibited for various carbohydrates and vicinal diols. Based on the mechanism, catalytic co-oxidation of glucose and methanol was proposed, showing an extremely high FA yield from glucose and high reactivity of methanol. The findings shed light into the mechanism of the product improvement with additives and pave an efficient way to produce a renewable energy carrier.

Novel chemical looping oxidation of biomass-derived carbohydrates to super-high-yield formic acid using heteropolyacids as oxygen carrier

In recent years, formic acid (FA) shows great potential in fuel cells and hydrogen storage. For FA production from renewable resources, catalytic aerobic oxidation of biomass to FA has been reported. However, the yield of by-product CO2 is fairly high, limiting the FA selectivity and causing greenhouse gas emission. Herein, a novel chemical looping oxidation of biomass-derived carbohydrates to FA was first proposed. A heteropolyacid H8PV5Mo7O40 (HPA-5) was selected as an excellent oxygen carrier. Oxidation of carbohydrates to FA and re-oxidation of reduced HPA-5 (HPA-5red) by O2 were separately performed, by which the FA yield from glucose achieved 95.4%. The extremely high yield of FA is attributed to two reasons. On one hand, the chemical looping process avoids over-oxidation caused by the hydroxyl radicals formed in the re-oxidation of HPA-5red. On the other hand, abundant HPA-5 promotes the glucose oxidation to FA, suppressing the acid-catalyzed decomposition and the oxidation toward saccharic acids. Besides, HPA-5red can be completely re-oxidized by O2 and the chemical looping oxidation has stably performed well in five chemical cycles. This oxidation strategy also shows outstanding FA yields from xylan, cellulose and raw biomass.

Green synthesis of 5-hydroxymethylfurfural from biomass-derived carbohydrates using deep eutectic solvents as environmentally benign catalyst

Green synthesis of 5-hydroxymethylfurfural from biomass-derived carbohydrates using deep eutectic solvents as environmentally benign catalyst

Synergistic effects of bimetals and hierarchical structures in Mg–Sn-Beta-H zeolites for lactic acid synthesis from biomass-derived carbohydrates

The catalytically active sites and hierarchical structure in Mg–Sn-Beta-H zeolite exhibited a clear synergistic effect on the conversion of glucose to lactic acid by promoting the main reaction steps and inhibiting the progress of side reactions.

Selective oxidation of biomass-derived carbohydrate monomers

The article discusses the potential production processes for glucaric acid, and the efforts to develop more sustainable oxidation practices for its production, with a focus on the strengths and weaknesses of each method.

Temperature-responsive Zn-based catalysts for efficient catalytic conversion of biomass-derived carbohydrates to ethyl lactate

Chemical catalytic conversion of biomass-derived sugars to lactic acid has attracted considerable attention due to the cheap, abundant and renewable nature of biomass and its huge potential application in the synthesis of polylactic acid.

Room-temperature and ambient-pressure conversion of renewable carbohydrates to value-added aromatic N-heterocycles under ultrasonic irradiation conditions

We report a new approach that allows highly efficient one-step conversion of biomass-derived carbohydrates to high-value 2-methylquinoxalines in the presence of aryl-1,2-diamines in water at room temperature and under ambient pressure.

Chemocatalytic Conversion of Lignocellulosic Biomass to Ethanol: A Mini-Review

Ethanol has been widely used as a clean fuel, solvent, and hydrogen carrier. Currently, ethanol is generally produced through fermentation of starch- and sugarcane-derived sugars (e.g., glucose and sucrose) or ethylene hydration. Its production from abundant and inexpensive lignocellulosic biomass would facilitate the development of green and sustainable society. Biomass-derived carbohydrates and syngas can serve as important feedstocks for ethanol synthesis via biological and chemical pathways. Nevertheless, the biological pathway for producing ethanol through biomass-derived glucose fermentation has the disadvantages of long production period and carbon loss. These issues can be effectively mitigated by chemocatalytic methods, which can readily convert biomass to ethanol in high yields and high atomic efficiency. In this article, we review the recent advances in chemocatalytic conversion of lignocellulosic biomass to ethanol, with a focus on analyzing the mechanism of chemocatalytic pathways and discussing the issues related to these methods. We hope this mini-review can provide new insights into the development of direct ethanol synthesis from renewable lignocellulosic biomass.

Doubling Micropore of Carbon Skeleton via Regulating Molecular Structure of Carbohydrate for Oxygen Reduction Reaction

Functional carbon materials prepared from biomass-derived carbohydrates have attracted extensive interests due to their low cost and high catalytic potential for oxygen reduction reaction (ORR). In this work, the pyranose ring, which is the basic repeating unit in lignocellulosic biomass, can be easily converted into micropore-riched carbon skeleton via regulating the side chain C-containing group. In striking contrast to glucopyranose, the simple pyranose ring (xylopyranose) exhibits outstanding nitrogen fixation ability. But higher N content in the carbon skeleton can lead to a decrease in C content, which is detrimental to the graphitization and pore-forming of carbon product. Benefiting from abundant micropore structures (volume increases from 0.22 cm3 g−1 to 0.50 cm3 g−1), the electrochemical surface area of Glu-SSC-950 is much larger than that of Xyl-SSC-950. Concretely, the double layer capacitance of Glu-SSC-950 (14.9 mF cm−2) is more than twice that of Xyl-SSC-950 (6.4 mF cm−2). Furthermore, the Glu-SSC-950 displays a more positive half-wave potential (0.84 V) and higher peak power density of Al-air battery (467.8 mW cm−2) compared with Xyl-SSC-950 (0.76 V and 373.6 mW cm−2). In general, it compensates for the shortcomings of the screening of carbohydrate precursors for preparing ORR carbonaceous electrocatalysts.

Sustainable Catalytic Synthesis of 2,5-Diformylfuran from Various Carbohydrates

Versatile homogeneous and heterogeneous catalysts that convert carbohydrates to 2,5-diformylfuran (DFF) are essential for the development of sustainable processes for producing high-value chemicals from biomass-derived carbohydrates. An efficient catalytic system consisting of Br−, disulfide, and dimethylsulfoxide (DMSO) promoted the sustainable and selective synthesis of DFF in modest-to-good yields from various carbohydrates, such as fructose, glucose, mannose, galactose, and sucrose. Heterogeneous catalysts containing Br− also facilitated this reaction with recyclable high yields.