The electrocatalytic oxidation of 5‐hydroxymethylfurfural (HMF) provides a feasible way for utilization of biomass resources. However, how to regulate the selective synthesis of multiple value‐added ...products is still a great challenge. The cobalt‐based compound is a promising catalyst due to its direct and indirect oxidation properties, but its weak adsorption capacity restricts its further development. Herein, by constructing Ag─Co(OH)2 heterogeneous catalyst, the efficient and selective synthesis of 5‐hydroxymethyl‐2‐furanoic acid (HMFCA) and 2,5‐furan dicarboxylic acid (FDCA) at different potential ranges are realized. Based on various physical characterizations, electrochemical measurements, and density functional theory calculations, it is proved that the addition of Ag can effectively promote the oxidation of aldehyde group to a carboxyl group, and then generate HMFCA at low potential. Moreover, the introduction of Ag can activate cobalt‐based compounds, thus strengthening the adsorption of organic molecules and OH− species, and promoting the formation of FDCA. This work achieves the selective synthesis of two value‐added chemicals by one tandem catalyst and deeply analyzes the adsorption enhancement mechanism of the catalyst, which provides a powerful guidance for the development of efficient heterogeneous catalysts.
Ag─Co(OH)2 tandem heterogeneous electrocatalyst, which exhibits excellent 5‐hydroxymethylfurfural oxidation activity is constructed. The analytical results indicate that the tandem material can promote aldehyde oxidation in the low potential region, enhance the enrichment and transformation of reactants in the high potential region, and then efficiently obtain 5‐hydroxymethyl‐2‐furanoic acid and 2,5‐furan dicarboxylic acid in the tunable potential ranges.
•Fructose dehydration to 5-hydroxymethyl furfural (HMF) in a biphasic microreactor.•Stable operation with maximum HMF yield of 93% at a residence time of 2 s.•HMF space–time yield higher by 10 – ...2,500-fold than published reports.•Increased solvent-dependent performance above the extraction thermodynamic limit.•Exposed mass transfer limitations at longer residence times.
We conduct an experimental study of fructose dehydration to 5-hydroxymethyl furfural (HMF) in a biphasic microreactor as a function of residence time, temperature, and sugar loading using methyl butyl iso-ketone (MIBK) and 2-pentanol as extracting solvents. We demonstrate stable operation with maximum HMF yields of 93% and 87% in the two solvents, respectively, at 200 °C and a residence time of 2 s for a 5 wt% fructose aqueous feed. We report the highest optimal HMF space–time yield of 60 kg/L-hr at 200 °C (10 – 2,500-fold higher than published reports). Unexpectedly, an optimum organic-to-water ratio exists that depends on the solvent. Notably, we observe experimentally an increased fructose rate and HMF yield well above the extraction thermodynamic limit and hypothesize that the solvent plays a dual role, that of an extractant to protect HMF from degradation and a modifier of the fundamental chemistry. We expose mass transfer limitations of microreactors at longer residence times and higher temperatures and provide reactivity maps for their design. We show that batch reactors are unfit for high throughput and distributed manufacturing where small, farm-based systems are necessary.
Biorefinery is increasingly embraced as an environmentally friendly approach that has the potential to shift current petroleum-based chemical and material manufacture to renewable sources. Furanic ...compounds, particularly hydroxymethylfurfurals (HMFs) are platform chemicals, from which a variety of value-added chemicals can be derived. Their biomanufacture and biodegradation therefore will have a large impact. Here, we first review the potential industrial production of 4-HMF and 5-HMF, then we summarize the known microbial biosynthesis and biodegradation pathways of furanic compounds with emphasis on the enzymes in each pathway. We especially focus on the structure, function and catalytic mechanism of MfnB (4-(hydroxymethyl)-2-furancarboxyaldehyde-phosphate synthase) and hmfH (HMF oxidase), which catalyze the formation of phosphorylated 4-HMF and the oxidation of 5-HMF to furandicarboxylic acid (2,5-FDCA), respectively. Understanding the structure-function relationship of these enzymes will provide important insights in enzyme engineering, which eventually will find industry applications in mass-production of biobased polymers and other bulk chemicals in future.
The Cover Feature shows the potential of multiphase liquid systems for the oxidation of 5‐hydroxymethylfurfural (HMF) with tunable selectivity. By modifying the constituents of the multiphase system ...and the reaction parameters, the protocol allows complete control of the reaction selectivity that goes from partial to deep oxidation of both the hydroxy and carbonyl functions of HMF, allowing also for the in‐situ recycling of the catalyst in a semicontinuous mode. More information can be found in the Research Article by D. Polidoro et al.
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•We focus on productions of HMF, LA, and FAME over solid catalysts from biomass.•Challenges of using actual biomass and waste streams were highlighted in this work.•Constituents of ...biomass could interfere with and deactivate catalysts.•Complete evaluation of solid catalysts on actual biomass conversion is encouraged.
Biomass conversion to value-added chemicals and fuels over heterogeneous catalysts is one of the top issues in green chemistry. This review focuses on recent advances in the application of solid catalysts for producing three prominent bio-based chemicals, hydroxymethylfurfural (HMF), levulinic acid (LA) and fatty acid methyl ester (FAME) from biomass materials, respectively. Our work highlights the perspectives and challenges during the conversion of actual biomass, including the impact of complex constituents and impurities of biomass on the solid catalysts, mass transfer limitation in the reactions, and the stability and deactivation of the solid catalysts. Transformation of solid catalysts from research to industrialization necessitates future work on identification of interactions between the catalysts and actual biomass, and comprehensive evaluation of the suitability of the catalysts in the reaction systems.
Background: Human milk fortifier (HMF) is defined as a supplement added to breastmilk to increase calories, proteins, vitamins, and various nutrition of breastmilk. The purpose of HMF administration ...is to increase the concentration of breastmilk nutrients to improve the weight of very low birth weight preterm infants. The administration of HMF is insufficient to fulfill protein needs in 20-40% very low birth weight babies, thus the weight gain did not meet the expected target.Objective: To analyze characteristic differences between very low birth weight preterm infants who experienced weight gain according to the target and not according to the target on the administration of HMF.Methods: An analytical study with a case-control approach comparing case and control group, which was observed to determine characteristic differences between both groups. The samples were 52 very low birth weight preterm infants obtained by consecutive sampling. Data analysis includes descriptive analysis and hypothesis testing. Results: Data were obtained from medical records and consisted of 52 participants, including 26 very low birth weight premature infants who experienced weight gain according to the target and 26 who experienced weight gain not according to the target. There was no characteristic difference of cyanosis clinical symptoms (OR 2.3; 95% CI 0.51-10.4), chest retraction (OR 1.0; 95% CI 0.32-3.1), apnea of prematurity comorbid (OR 1.0; 95% CI 0.25-3.9), neonatal infections (OR 0.62; 95% CI 0.21-1.9), starting age of HMF administration (OR 0.62; 95% CI 0.21-1.89), bloating (OR 0.57; 95% CI 0.17-1.9), and vomiting (OR 1.18; 95% CI 0.38-3.7) in both groups.Conclusion: There was no characteristic difference between very low birth weight preterm infants who experienced weight gain according to the target and not according to the target on the administration of HMF.
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•Biomass conversion to HMF significantly depends on catalysts and solvents.•Bifunctional catalyst caters for tandem hydrolysis, isomerization, and dehydration.•Lewis-to-Brønsted acid ...ratio and acid strength primarily determine HMF selectivity.•Co-solvents are kinetically and thermodynamically favourable for HMF production.•Biphasic system enhances HMF selectivity by suppressing side reactions.
Conversion of biomass waste to hydroxymethylfurfural (HMF), a value-added platform chemical, has captured great research interests driven by the economic and environmental incentives. This review evaluates the recent development of biomass conversion systems for high HMF yield and selectivity, with a focus on the performance of emerging catalysts and solvents from a mechanistic view. We highlight that the ratio and strength of Brønsted and Lewis acid in bifunctional catalyst are critical for maximizing HMF production by selective improvement in the kinetics of desirable reactions (hydrolysis, isomerization, and dehydration) over undesirable reactions (rehydration, polymerization). The characteristics of solvent mixture such as functional groups and speciation govern the reactivity of substrate towards desirable reactions and stability of HMF and intermediates against side reactions. Research efforts to unravel the interactions among co-catalysts/co-solvents and between catalysts and solvents are encouraged, thereby engineering a synergistic conversion system for biomass valorization.
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•A topotactic transformation was proposed via rapid calcination at 300 °C in air for only 5 min to transform the P123-encapsulated ultrathin CoOxHy nanosheets.•This facile ...post-synthetic treatment allows the formation of surface-clean, hierarchical polycrystalline Co3O4-VO nanosheets with enriched oxygen vacancies.•Co3O4-VO outperforms the as-synthesized CoOxHy nanosheets and the conventionally calcined Co3O4 in OER and particularly in HMF electrooxidation to FDCA.
Surfactant-free, freestanding, and hierarchical two-dimensional (2D) polycrystalline cobalt oxide (Co3O4) nanosheets with enriched oxygen vacancies (Co3O4-VO) were synthesized by a topotactic conversion via rapid calcination of the solvothermally synthesized ultrathin cobalt oxide hydrate (CoOxHy) nanosheets. The topochemically transformed Co3O4-VO outperforms the as-synthesized P123-encapsulated CoOxHy nanosheets and their conventionally calcined Co3O4 counterpart for both electrochemical oxygen evolution and 5-hydroxymethylfurfural (HMF) oxidation to 2,5-furandicarboxylic acid (FDCA), owing to their largely preserved 2D structure and elimination of P123 for abundant exposed surface active sites. More importantly, the strain-induced oxygen vacancies at grain boundaries of Co3O4 nanocrystallines are also proposed to be responsible for the improved electrooxidation performance. Furthermore, Co3O4-VO exhibits remarkable long-term stability during the chronoamperometric test in 1 M KOH.
•Effect of time, temperature and pH on quality parameters of dalbergia honey.•Increase in temperature led to increase in HMF and decrease in diastase activity.•Maximum invertase activity was (18.21 ...IN) at 4.8 pH.•Optimized values of quality parameters were 7.78 mg/kg, 17.95 DN and 13.96 IN.
The current study explored the botanical origin of Dalbergia (Dalbergia sissoo) honey source using melissopalynology. The 20 runs in triplicate were evaluated using the composite central rotatable design (CCRD) for the analysis of effect of heating (45–55 ºC), pH (4.8–5.8) and time (5–15 min) on attributes features like hydroxymethylfurfural (HMF) content, diastase & invertase activity of Dalbergia honey with Response Surface Method (RSM). A significant effect of process variables on three responses has btabeen observed from the statistical data. The amount of HMF content increased at higher temperature and pH. However, the diastase activity can be well monitored in the increased temperature. The invertase activity of honey was significantly (P < 0.0001) reduced for every pH value from 4.8 to 5.8. The results attained when heating beyond 49 ºC as well as a higher pH with prolonged time could alter HMF content, diastase and invertase activity, which may deteriorate the grade of honey.
The electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) represents a promising pathway for producing biomass-derived value-added chemicals. Nevertheless, the use of extremely expensive ion ...exchange membranes (IEMs) as separators significantly sacrifices the economic benefit in large-scale applications. Herein, we report a cost-effective non-fluorine cation exchange membrane (CEM) by grafting sulfonic acid (-SO3-) groups onto the aromatic side chain of the polyethersulfone (PES) polymer. By tuning the content of –SO3- groups, the physicochemical properties of the resulting CEMs can be easily adjusted. Impressively, the optimal HBS-PES-1.0 CEM with fully grafted –SO3- groups can achieve a high HMF conversion of 100 %, FDCA selectivity of 98.0 %, and Faradaic efficiency of 98.3 % when used as the separator for electrocatalytic oxidation of HMF, surpassing that of the commercial Nafion 117 membrane (100 % HMF conversion, 98.1 % FDCA selectivity, and 97.4 % Faradaic efficiency). This study provides a cost-effective and high-performance CEM as a substitute for the expensive commercial membrane, paving the way to large-scale commercial applications of biomass upgrading through the electrolysis process.
A cost-effective non-fluorine sulfonated polymer with low membrane area resistance and excellent alkali-resistance is reported, which exhibits comparable performance to commercial expensive Nafion membrane in the application of HMF electrooxidation to FDCA. Display omitted
•A non-fluorine side-chain cation exchange membrane is prepared for electrooxidation.•The interconnected ion channels endow the membrane with high ion transport rate.•The optimal membrane exhibits comparable performance to Nafion for HMF conversion.
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