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Ni phosphides and NiCo alloys are extensively explored for their remarkable efficiency in biomass alcohol oxidations, yet the underlying mechanisms remain inadequately understood. This study thoroughly elucidates the roles of Ni, Co, and P in improving the catalytic performance of Ni‐Co‐P catalysts for the electrochemical conversion of 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA), a promising biomass‐derived building block replacing terephthalic acid. Phosphorization of Ni results in the partial formation of Ni2P phase and significantly boosts the formation of the reactive NiOOH phase on the surface, which is the crucial catalytic phase for converting HMF into FDCA. The integration of Co into the heterojunction between Ni2P and NiOOH enhances the oxidation reactivity of 5‐formyl‐2‐furancarboxylic acid (FFCA), a pivotal intermediate influencing FDCA productivity, by selectively stabilizing aldehydes, thereby promoting further oxidation rather than surface desorption. in situ/operando spectroscopic analyses consistently highlight the equal significance of the rapid generation of NiOOH and the robust adsorption of reactant molecules at the surface in achieving high catalytic performance. These insights into elemental contributions set a new standard for designing multi‐component electrocatalysts for efficient biomass alcohol oxidation. [ABSTRACT FROM AUTHOR]

The key challenge for 5‐hydroxymethylfurfural oxidation reaction (HMFOR) lies in understanding the synergistic interactions between active sites and adsorption sites, but the uncertain spatial positions of these two sites largely limit their synergistic effect. Here, an embedded Pd/NiFe layered double hydroxide (LDH) with Pd nanoparticles (NPs) (3.6 nm) far larger than the interlayer spacing of LDH is reported, which results in the in situ generation of the defective structures at the interface of the NiFe laminate. The Pd/NiFe shows a lower onset potential of 1.34 V compared to NiFe (1.42 V). Experimental and theoretical calculations reveal that the Pd NPs exhibit a high level of orbital overlap with HMF, leading to a strong adsorption tendency and an increased local concentration of HMF near the Pd NPs. The Ni defects generated around Pd NPs result in the 3d‐orbitals of adjacent Ni sites approaching the Fermi level, reducing the oxidation barrier from Ni2+‐OH to Ni3+‐O active sites. Furthermore, this work provides crucial evidence for the hydration interactions between the aldehyde groups in HMF and the hydroxyl groups on the catalyst surface, demonstrating that the removal ability of the latter one can have an important influence on HMFOR activity. [ABSTRACT FROM AUTHOR]

The copper–cobalt metal oxide composite magnesium oxide catalyst loaded with Ru has achieved the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to the bio-based polyester monomer 2,5-furandicarboxylic acid (FDCA) under base-free conditions. Several Ru/Cu-Co-O·MgO catalysts were prepared, with Cu-Co-O being a combination of CuO and Co3O4 . The catalyst’s activity was boosted by the synergistic interaction between copper and cobalt, as well as an optimal copper-to-cobalt molar ratio. Optimal catalytic activity was observed in the Ru4/Cu1-Co1-O·MgO catalyst, loaded with 4 wt% Ru when copper-to-cobalt molar ratio of 1:1 and magnesium oxide compounding amount of 6 mmol were employed. The inclusion of MgO and the load of Ru not only expanded the specific surface area of the catalyst but also heightened its basicity. Additionally, the presence of loaded Ru improved the catalyst’s reducibility at low temperatures. In aqueous solution under oxygen pressure, the conversion rate of HMF achieved 100%, and the yield of FDCA was 86.1%. After five reaction cycles, examining the catalyst and solution revealed that Ru nanoparticles resisted leaching or oxidation, and MgO exhibited only slight dissolution. The green separation of the product was achieved using semi-preparative liquid chromatography, selectively collecting the FDCAcontaining solution by exploiting variations in interactions between solutes and the stationary/mobile phases. The subsequent steps involved rotary evaporation and drying, resulting in FDCA powder with a purity exceeding 99%. Notably, this approach eliminated the need to introduce concentrated hydrochloric acid into the system for FDCA separation, providing a novel method for synthesising powdered FDCA. [ABSTRACT FROM AUTHOR]

Maximizing the loadings of active centers without aggregation for a supported catalyst is a grand challenge but essential for achieving high gravimetric catalytic activity, especially toward multi‐step reactions. The oxidation of 5‐hydroxymethylfurfural (HMF), a key biomass‐derived platform molecule, into 2,5‐furandicarboxylic acid (FDCA), a promising alternative to polyester monomer, is such a multi‐step reaction that involves 6 proton and electron transfers. This process often demands strong alkaline environment but also suffers from the alkali‐driven polymerization side‐reaction. Meanwhile, neutral media ameliorates the polymerization, but lacks efficient catalyst toward deep oxidation. Herein, we devised a strategy of creating ultra‐dense supported Ru oxide clusters via directed ion exchange in a Co hydroxyanion (CoHA) support material. Pyrimidine ligands were first incorporated into the CoHA interlayers, and the subsequent evacuation of pyrimidines created porous channels for the directed ion exchange with the built‐in anions in CoHA, which allowed the dense and mono‐disperse functionalization of RuCl62− anions and their resulting Ru oxide clusters. These ultra‐dense Ru oxide clusters not only enable high HMF electrooxidation currents under neutral conditions but also create microscopic channels in‐between the clusters for the expedited re‐adsorption and oxidation of intermediates toward highly oxidized product, such as 5‐formyl‐2‐furoic acid (FFCA) and FDCA. A two‐stage HMF oxidation process, consisting of ambient conversion of HMF into FFCA and FFCA oxidation into FDCA under 60 °C, was eventually developed to first achieve a high FDCA yield of 92.1 % under neutral media with significantly reduced polymerization. [ABSTRACT FROM AUTHOR]

The oxidation of 5‐hydroxymethylfurfural (HMF) to 2,5‐diformylfuran (DFF) is a key reaction in valorizing biomass. DFF is hardly soluble in water, while HMF is often obtained from biorefineries in crude wet organic fractions. Thus, the reaction is challenging for both biocatalysis performed in aqueous media, and for chemocatalysis where the presence of water often results in catalyst poisoning. Galactose oxidase (GalOx) can selectively oxidize HMF to DFF and displays promising activity in aqueous‐organic media. In this study, GalOx was immobilized on ten carriers, assessing the immobilization yield, activity, and stability. Covalently immobilized GalOx catalyzed the oxidation of HMF to DFF in neat and water‐saturated EtOAc, and in biphasic systems of various water contents. At 50 % v/v H2O, the reaction was conducted at a semi‐preparative scale (50 mL) with no adverse effect on DFF yield. Some limitations arise, such as enzyme deactivation, and adsorption of DFF to the support, particularly in the aqueous fraction. Future options to upgrade the route may include designed stable enzymes under the presence of HMF/DFF, and the setup of microaqueous systems where DFF adsorption is minimized. The use of wet EtOAc media would be a promising approach in future biorefineries employing inexpensive crude wet organic fractions. [ABSTRACT FROM AUTHOR]

The design of an "H"‐shaped reactor has been studied to satisfy the possibility of using a triphasic medium to transform d‐glucose into 5‐hydroxymethylfurfural (HMF) by a hybrid catalytic process using an immobilized glucose isomerase, allowing the isomerization of D‐glucose to d‐fructose, and a heterogeneous chemical catalyst to catalyze the dehydration of d‐fructose to HMF. The various parameters influencing the transport of d‐fructose within the reactor were studied, namely the difference in pH between the two aqueous phases, the agitation and the quantity of 3,4‐DCPBA/Aliquat336® used to extract and transport continuously the d‐fructose. The pH discrepancy, which must be between 5.0 and 5.5, turns out to be the real driving force behind the extraction of D‐fructose. The D‐Fru/3,4‐DCPBA molar ratio of 1/0.25 allowed the transport of more than 80 % of the D‐fructose initially present and shows that the same molecule of 3,4‐DCPBA is involved at least twice in the transport of D‐fructose and that the 3,4‐DCPBA/Aliquat336® couple performs a turnover within the organic phase. Finally, a HMF production yield of 30.9 % and an isomerization yield of 79.1 % were obtained, illustrating the shift in the isomerization equilibrium made possible by a D‐fructose extraction yield of 96.8 %. [ABSTRACT FROM AUTHOR]

Copyright of Harran Journal of Agricultural & Food Science is the property of Harran University, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The presence of toxic compounds in lignocellulosic hydrolysates (LCH) is among the main barriers affecting the efficiency of lignocellulose-based fermentation processes, in particular, to produce biofuels, hindering the production of intracellular lipids by oleaginous yeasts. These microbial oils are promising sustainable alternatives to vegetable oils for biodiesel production. In this study, we explored adaptive laboratory evolution (ALE), under methanol- and high glycerol concentration-induced selective pressures, to improve the robustness of a Rhodotorula toruloides strain, previously selected to produce lipids from sugar beet hydrolysates by completely using the major C (carbon) sources present. An evolved strain, multi-tolerant not only to methanol but to four major inhibitors present in LCH (acetic acid, formic acid, hydroxymethylfurfural, and furfural) was isolated and the mechanisms underlying such multi-tolerance were examined, at the cellular envelope level. Results indicate that the evolved multi-tolerant strain has a cell wall that is less susceptible to zymolyase and a decreased permeability, based on the propidium iodide fluorescent probe, in the absence or presence of those inhibitors. The improved performance of this multi-tolerant strain for lipid production from a synthetic lignocellulosic hydrolysate medium, supplemented with those inhibitors, was confirmed. [ABSTRACT FROM AUTHOR]

Furandicarboxylic acid (FDCA) is recognized as a valuable product of hydroxymethylfurfural (HMF) derived from cellulosic materials as an abundant renewable source. It could find future bioplastic application if a feasible separation process is developed. To find a commercially available solvent, FDCA should be selectively separated from HMF and the downstream process be supported by pyrolysis-gas chromatography-mass spectrometry experiments in line with density functional theory (DFT). Evaluation of the sigma potential and sigma surface analysis demonstrated that benzene and ethyl acetate enjoyed better extraction and HMF selectivity, whereas FDCA exhibited ideal behavior in the presence of DMF and DMSO solvents. It was proved that the hydrophobicity could be changed by improving the hydrogen-bonding interaction between them. Moreover, the up-down selection of classes of solvents based on the experimental data found by GC-MS revealed that polar molecular solvents (ethanol-water) were more compatible with carboxylic acids and alcohol compounds, while n-hexane was a desirable solvent for phenolic compounds. It was found that levoglucosan retained a significant fraction of water compared to other solvents, which need to be considered for further economic and environmental analysis under the multifaceted framework of biomass-derived products.

The production of 2,5-furandicarboxylic acid (FDCA) as a biobased commodity chemical has gained great importance over the last years. The possibility of replacing conventional polyethylene terephthalate (PET)-based plastics by polyethylene furanoate (PEF) is accelerating applied research in the direction of novel and highly productive synthesis routes to FDCA. This paper explores the patent activities related to FDCA production, with particular emphasis on the potential role that enzymatic catalytic methods may have. An increasing number of patent applications (and granted ones) have been disclosed over the last decade. The innovation is set on the development of multi-step catalytic processes, involving multi-enzymatic and chemoenzymatic cascades, or using whole-cells, either as resting (non-growing) biocatalysts or as living organisms in fermentative processes. Moreover, other innovative paths use substrates different from fructose and 5-hydroxymethylfurfural (HMF), such as gluconic acid, or furfural. Overall, opportunities for innovation exist, albeit current production metrics in biotechnological methods remain mostly at the proof-of-concept level. Large development efforts to reach industrial targets are needed, which may be stimulated by the less severe processing conditions expected for biotechnology, leading to energy savings, less by-product formation, and to the valorization of crude effluents.

Steam pretreatment is an effective approach to open up the intact lignocellulosic matrix for biofuels and animal feed production. However, crop residues especially corn stover contain certain amounts of water-soluble carbohydrates (WSC), which are easily degraded into toxic 5-hydroxymethylfurfural (HMF) at high temperature and bring negative effects on subsequent utilization of lignocellulose biomass. Few studies have focused on the WSC loss and proposed a corresponding solution to utilize them in steam pretreatment. This study introduced a solid-state fermentation prior to steam pretreatment of corn stover to convert WSC into lactic acid, which could catalyze the hydrolysis of hemicellulose and acetyl groups in pretreatment. Compared to the regular steam pretreatment at the same severity (180 °C for 5 min), the conversion yields of xylan and arabinan in the steam pretreatment were both increased from 9.6% and 37.2% to 28.8% and 69.6%, respectively. Cellulose conversion also increased from 48.1% to 50.7% in the subsequent enzymatic hydrolysis. On the other hand, the generation of the toxic HMF reduced by 42.1% due to the pre-conversion of WSC into the relatively thermal stable lactic acid. This study provided an effective approach to process corn stover with higher hydrolysis yield and lower inhibitor generation. [ABSTRACT FROM AUTHOR]

The presence of toxic compounds in lignocellulosic hydrolysates (LCH) is among the main barriers affecting the efficiency of lignocellulose-based fermentation processes, in particular, to produce biofuels, hindering the production of intracellular lipids by oleaginous yeasts. These microbial oils are promising sustainable alternatives to vegetable oils for biodiesel production. In this study, we explored adaptive laboratory evolution (ALE), under methanol- and high glycerol concentration-induced selective pressures, to improve the robustness of a Rhodotorula toruloides strain, previously selected to produce lipids from sugar beet hydrolysates by completely using the major C (carbon) sources present. An evolved strain, multi-tolerant not only to methanol but to four major inhibitors present in LCH (acetic acid, formic acid, hydroxymethylfurfural, and furfural) was isolated and the mechanisms underlying such multi-tolerance were examined, at the cellular envelope level. Results indicate that the evolved multi-tolerant strain has a cell wall that is less susceptible to zymolyase and a decreased permeability, based on the propidium iodide fluorescent probe, in the absence or presence of those inhibitors. The improved performance of this multi-tolerant strain for lipid production from a synthetic lignocellulosic hydrolysate medium, supplemented with those inhibitors, was confirmed.

Summary: 5‐Hydroxymethylfurfural (HMF) is a versatile biomass‐derived chemical from multifunctional compound. It is also a promising intermediate compound used in various chemical and fuel applications, including pharmaceuticals, solvents, biofuel, and other intermediates. The demand for innovative approaches to renewable energy resources has risen to diminish the dependency on petroleum‐based products and to seek economical and environmentally friendly processes for supplying energy to the world. Fructose, glucose, cellulose, and lignocellulosic materials are the most common feedstocks used to synthesize HMF. This study reviews previous studies on the development of high yield and selectivity of HMF from technical and economic perspectives. The article highlights a few significant parameters and focused on the solvent system used for the synthesis of HMF in the lab scale and through the development of process modeling using simulation software such as Aspen Plus to perform the techno‐economic analysis (TEA), which analyses the economic feasibility of the developed production process. The TEA can estimate the capital investment needed, including feedstock, catalyst, and equipment cost, and the final product's minimum selling price (MSP). HMF is cost‐efficient due to higher operational costs from the higher cost of fructose feedstock. By studying this analysis, the overall cost of HMF production can be minimized and more economically competitive with current commercial production. Besides, to make the production of HMF more cost‐effective, more research into alternative lignocellulosic feedstocks and the development of novel catalytic systems is needed. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Tiangong University is the property of Journal of Tianjin Polytechnic University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There is a demand for renewable resources, such as biomass, to produce compounds considered as platform molecules. This study deals with dehydration of fructose for the formation of 5-hydroxymethylfurfural (HMF), a feedstock molecule. Different catalysts (aluminosilicates, niobic acid, 12-tungstophosphoric acid—HPW, and supported HPW/Niobia) were studied for this reaction in an aqueous medium. The catalysts were characterized by XRD, FT-IR, N2 sorption at −196 °C and pyridine adsorption. It was evident that the nature of the sites (Brønsted and Lewis), strength, quantity and accessibility to the acidic sites are critical to the conversion and yield results. A synergic effect of acidity and mesoporous area are key factors affecting the activity and selectivity of the solid acids. Niobic acid (Nb2O5·nH2O) revealed the best efficiency (highest TON, yield, selectivity and conversion). It was determined that the optimum acidity strength of catalysts should be between 80 to 100 kJ mol−1, with about 0.20 to 0.30 mmol g−1 of acid sites, density about 1 site nm−2 and mesoporous area about 100 m2 g−1. These values fit well within the general order of the observed selectivity (i.e., Nb2O5 > HZSM-5 > 20%HPW/Nb2O5 > SiO2-Al2O3 > HY > HBEA).

The copper-cobalt metal oxide composite magnesium oxide catalyst loaded with Ru has achieved the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to the bio-based polyester monomer 2,5-furandicarboxylic acid (FDCA) under base-free conditions. Several Ru/Cu-Co-O·MgO catalysts were prepared, with Cu-Co-O being a combination of CuO and Co 3 O 4 . The catalyst's activity was boosted by the synergistic interaction between copper and cobalt, as well as an optimal copper-to-cobalt molar ratio. Optimal catalytic activity was observed in the Ru 4 /Cu1-Co1-O·MgO catalyst, loaded with 4 wt% Ru when copper-to-cobalt molar ratio of 1:1 and magnesium oxide compounding amount of 6 mmol were employed. The inclusion of MgO and the load of Ru not only expanded the specific surface area of the catalyst but also heightened its basicity. Additionally, the presence of loaded Ru improved the catalyst's reducibility at low temperatures. In aqueous solution under oxygen pressure, the conversion rate of HMF achieved 100%, and the yield of FDCA was 86.1%. After five reaction cycles, examining the catalyst and solution revealed that Ru nanoparticles resisted leaching or oxidation, and MgO exhibited only slight dissolution. The green separation of the product was achieved using semi-preparative liquid chromatography, selectively collecting the FDCA-containing solution by exploiting variations in interactions between solutes and the stationary/mobile phases. The subsequent steps involved rotary evaporation and drying, resulting in FDCA powder with a purity exceeding 99%. Notably, this approach eliminated the need to introduce concentrated hydrochloric acid into the system for FDCA separation, providing a novel method for synthesising powdered FDCA.

5‐hydroxymethylfurfural (HMF) is produced upon dehydration of C6 sugars in biorefineries. As the product, it remains either in aqueous solutions, or is in situ extracted to an organic medium (biphasic system). For the subsequent oxidation of HMF to 2,5‐furandicarboxylic acid (FDCA), 'media‐agnostic' catalysts that can be efficiently used in different conditions, from aqueous to biphasic, and to organic (microaqueous) media, are of interest. Here, the concept of a one‐pot biocatalytic cascade for production of FDCA from HMF was reported, using galactose oxidase (GalOx) for the formation of 2,5‐diformylfuran (DFF), followed by the lipase‐mediated peracid oxidation of DFF to FDCA. GalOx maintained its catalytic activity upon exposure to a range of organic solvents with only 1 % (v/v) of water. The oxidation of HMF to 2,5‐diformylfuran (DFF) was successfully established in ethyl acetate‐based biphasic or microaqueous systems. To validate the concept, the reaction was conducted at 5 % (v/v) water, and integrated in a cascade where DFF was subsequently oxidized to FDCA in a reaction catalyzed by Candida antarctica lipase B. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Chemical & Petroleum Engineering is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There is a demand for renewable resources, such as biomass, to produce compounds considered as platform molecules. This study deals with dehydration of fructose for the formation of 5-hydroxymethylfurfural (HMF), a feedstock molecule. Different catalysts (aluminosilicates, niobic acid, 12-tungstophosphoric acid—HPW, and supported HPW/Niobia) were studied for this reaction in an aqueous medium. The catalysts were characterized by XRD, FT-IR, N2 sorption at −196 ◦C and pyridine adsorption. It was evident that the nature of the sites (Brønsted and Lewis), strength, quantity and accessibility to the acidic sites are critical to the conversion and yield results. A synergic effect of acidity and mesoporous area are key factors affecting the activity and selectivity of the solid acids. Niobic acid (Nb2O5 ·nH2O) revealed the best efficiency (highest TON, yield, selectivity and conversion). It was determined that the optimum acidity strength of catalysts should be between 80 to 100 kJ mol−1, with about 0.20 to 0.30 mmol g−1 of acid sites, density about 1 site nm−2 and mesoporous area about 100 m² g −1 . These values fit well within the general order of the observed selectivity (i.e., Nb2O5 > HZSM-5 > 20%HPW/Nb2O5 > SiO2 -Al2O3 > HY > HBEA). [ABSTRACT FROM AUTHOR]

5-Hydroxymethylfurfural (HMF) is synthesized by the thermal decomposition of the sugars. Numerous types of food products are having a significant amount of HMF. Besides the thermal processing, other food processing methods (drying and dehydration, roasting, baking and storage of the product) are important factors for the synthesis of the HMF. HMF possesses different health effects including positive and negative health effects. Only few regulatory bodies have issued the guidelines and limits related to HMF. The present review has been planned to explore the HMF in terms of synthesis, occurrence, the effect of food processing, health effects and the safety guidelines. [ABSTRACT FROM AUTHOR]

The development of enzymatic processes for the environmentally friendly production of 2,5-furandicarboxylic acid (FDCA), a renewable precursor for bioplastics, from 5-hydroxymethylfurfural (HMF) has gained increasing attention over the last years. Aryl-alcohol oxidases (AAOs) catalyze the oxidation of HMF to 5-formyl-2-furancarboxylic acid (FFCA) through 2,5-diformylfuran (DFF) and have thus been applied in enzymatic reaction cascades for the production of FDCA. AAOs are flavoproteins that oxidize a broad range of benzylic and aliphatic allylic primary alcohols to the corresponding aldehydes, and in some cases further to acids, while reducing molecular oxygen to hydrogen peroxide. These promising biocatalysts can also be used for the synthesis of flavors, fragrances, and chemical building blocks, but their industrial applicability suffers from low production yield in natural and heterologous hosts. Here we report on heterologous expression of a new aryl-alcohol oxidase, MaAAO, from Moesziomyces antarcticus at high yields in the methylotrophic yeast Pichia pastoris (recently reclassified as Komagataella phaffii). Fed-batch fermentation of recombinant P. pastoris yielded around 750 mg of active enzyme per liter of culture. Purified MaAAO was highly stable at pH 2–9 and exhibited high thermal stability with almost 95% residual activity after 48 h at 57.5 °C. MaAAO accepts a broad range of benzylic primary alcohols, aliphatic allylic alcohols, and furan derivatives like HMF as substrates and some oxidation products thereof like piperonal or perillaldehyde serve as building blocks for pharmaceuticals or show health-promoting effects. Besides this, MaAAO oxidized 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) to FFCA, which has not been shown for any other AAO so far. Combining MaAAO with an unspecific peroxygenase oxidizing HMFCA to FFCA in one pot resulted in complete conversion of HMF to FDCA within 144 h. MaAAO is thus a promising biocatalyst for the production of precursors for bioplastics and bioactive compounds. Key points: • MaAAO from M. antarcticus was expressed in P. pastoris at 750 mg/l. • MaAAO oxidized 5-hydroxymethyl-2-furancarboxylic acid (HMFCA). • Complete conversion of HMF to 2,5-furandicarboxylic acid by combining MaAAO and UPO. [ABSTRACT FROM AUTHOR]

In this work, a uniquely designed imidazolium-based dicationic ionic liquid (IL) was synthesized as a greener template and applied for the synthesis of ZSM-5 zeolite as a heterogeneous catalyst for the dehydration of fructose to 5-hydroxymethylfurfural (HMF). Characterization results confirmed that due to the presence of dicationic IL as template, effective interactions and structural alterations occurred during the construction of zeolitic framework wherein the vertices of ZSM-5 consisting of Al or Si and O elements were assumed to be bonded between the vertices of dicationic IL-assisted zeolite ZSM-5 catalyst. This resulted in superior structural advantages such as highly crystalline nature and stability as well as variation in mesopores when compared to commercial ZSM-5. Additionally, various reaction variables were investigated wherein synthesized dicationic IL-assisted ZSM-5 zeolite catalyst in the presence of [BMIm][Cl] as solvent demonstrated 95% conversion of fructose and 67.2% yield of HMF at 110°C within 90 min. The altered surface area and porous nature of synthesized ZSM-5 due to the presence of dicationic IL as template was responsible for the enhanced catalytic performance under mild reaction conditions. Most significantly, being a solid catalyst, the newly developed dicationic IL-assisted zeolite ZSM-5 catalyst showed recyclability for four recycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of Cu/CoCeO x catalysts were prepared via a co-precipitation method. • Ratio of CoO x to Co was tuned via H 2 reduction temperature. • Synergy between CuCo and CoCeO x sites facilitate hydrogenation of HMF. • >90% yield of DMF was obtained over the optimized Cu/CoCeO x catalyst. Much attention has been attracted on the production of renewable biofuels through efficient catalytic transfer hydrogenation (CTH) reaction. In this study, a series of Cu/CoCeO x catalysts were synthesized by a facile coprecipitation method for CTH of 5-hydroxymethylfurfural (HMF) to different products with 2-propanol as a hydrogen donor, and the dual active sites of CuCo and CoCeO x were tuned via H 2 -reduction temperature. A 92.2% yield of 2,5-dihydroxymethylfuran (DHMF) was achieved at 150 °C over the Cu 4 Co 8 Ce 4 -300 catalyst, and a 95.4% yield of 2,5-dimethylfuran (DMF) was obtained over the Cu 4 Co 10 Ce 2 -600 catalyst at 170 °C. The roles of the dual active sites were further investigated, and the results showed that Cu species were identified as the major active sites of 2-propanol dehydrogenation, CoCeO x sites were responsible for the conversion of HMF to DHMF, and CuCo bimetallic nanoparticles promoted the cleavage of C-O in DHMF to obtain DMF. XRD, Raman, and HAADF-STEM analysis confirmed the existence of these sites. XPS and H 2 -TPR verified the formation of CuCo bimetallic nanoparticles, and NH 3 -TPD was employed to evaluate the acidity of the surface. Furthermore, in situ DRIFT of furfuryl alcohol and performance test experiments were conducted to understand the synergistic mechanism of dual active sites in hydrogen transfer from 2-propanol to HMF. This work provides a strategy to obtain different target products via tuning dual active sites. [ABSTRACT FROM AUTHOR]

• HMF can inhibit the production of hydrogen and change the community structure of microorganisms. • Low concentrations of HMF could be utilized to increase methane production. • HMF can interfere with the normal physiological functions of microorganisms. • The strategies of reducing the effects of HMF on fermentation were summarized. Anaerobic fermentation is a clean production process for recycling of many agricultural and industrial wastes. During anaerobic fermentation, the existence of various inhibitors often leads to low efficiency or even failure of anaerobic digesters. 5-hydroxymethylfurfural (HMF) is such an inhibitor which can be produced in the pretreatment of biomass for subsequent anaerobic digestion. This paper provides a review of various production methods of HMF and its effects on hydrogen production, methane production and ethanol production through fermentation. The conversion and removal of HMF were summarized from the aspects of biomass pretreatment, non-biological treatment and biological treatment. This article aims to provide new ideas and methods for reducing the inhibition effect of HMF on anaerobic fermentation of biomass and restoring the performance of the anaerobic fermentation. [ABSTRACT FROM AUTHOR]