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The development of safe, economical and highly efficient oxidation systems for the production of chemicals from biomass remains a significant and challenging target. Here, we first found a unique air-assisted reaction mechanism for the non-pressurized oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) using dimethylsulfoxide (DMSO) as an O-donor over CoZrNC-MCM, which affords exceptional productivity among all non-noble catalysts. The combination of control experiments and density functional theory (DFT) calculations reveals that the air-assisted DMSO oxidation pathway is activated by the co-adsorption of DMSO and O2 on Co-(pyrrolic N–C) pairs of CoNC-MCM. ZrNC species in CoZrNC-MCM will be thermally disintegrated to release ZrO2+ and provide the corresponding cation vacancies that might be able to capture Co atoms to form additional Co-(pyrrolic N–C) active pairs, resulting in the increase of catalytic activity. The released ZrO2+ is well dispersed over Al-MCM-41 in the form of zirconia, which contributes to the dehydration of fructose to HMF. In this way, a one-step approach for synthesizing DFF from fructose is achieved by the cooperation of zirconia and Co-(pyrrolic N–C) pairs over CoZrNC-MCM. [ABSTRACT FROM AUTHOR]

2,5‐Bis(hydroxymethyl)furan (BHMF) as well as furfuryl alcohol (FFA) are considered as highly valuable biomass‐derived alcohols resembling aromatic monomers in polymer synthesis. Herein, a series of cobaltic nitrogen‐doped carbon (Co−NC) catalysts calcinated at different temperatures were synthesized and tested for the solvent‐free hydrogenation of 5‐hydroxymethylfurfural (HMF) to prepare BHMF. It was found that the Co−NC catalyst calcinated at 600 °C (Co−NC‐600) exhibited a superior catalytic activity in the hydrogenation reaction mainly due to the doping of graphitic N, which probably facilitated the polarization of H2 to afford H+ and H−. Consequently, Co−NC‐600 offered a high BHMF/FFA yield greater than 90 % with a nearly complete conversion of HMF/furfural (FF) at the optimal conditions (80 °C, 4 h, and 5 MPa H2). After the hydrogenation reaction, Co−NC catalyst was facilely recycled by magnetic separation, and the obtained BHMF/FFA was then successfully transformed into hypercrosslinked polymers with an excellent CO2/H2 storage capacity comparable to aromatic hydroxymethyl polymers. Therefore, this is a novel and facile two‐step pathway for the conversion of biomass‐derived HMF/FF towards functional polymers from both industrial and environmental perspectives. [ABSTRACT FROM AUTHOR]

The direct fabrication of furan‐2,5‐dimethylcarboxylate (FDMC), a promising renewable monomer, from biomass‐derived 5‐hydroxymethylfurfural (HMF) is a cutting‐edge process. In this contribution, an elaborately designed N‐doped carbon‐supported CoCu bimetallic catalyst (CoxCuy‐NC; x/y=9:1, 7:3, 4:6, which represents the designed molar ratio of Co and Cu in the catalyst), which could offer a desirable FDMC yield of 95 % under mild and base‐free conditions (Co7Cu3‐NC, 2 bar O2, 80 °C, 4 h) is described for the oxidative esterification of HMF. Notably, an FDMC formation rate of 6.1 molFDMC molCo−1 h−1 was achieved over Co7Cu3‐NC, which represents the highest catalytic efficiency so far among Co‐based catalytic systems. It has been demonstrated that Cu‐doping in Co7Cu3‐NC catalyst brings about more active sites (Co‐Nx species) with stronger molecular oxygen activation ability. The increase of surface N content of Co7Cu3‐NC also improves basicity of the catalyst, which favors the hydrogen abstraction process during the HMF oxidative esterification reaction. These findings may pave an efficient and green way for the synthesis of sustainable bio‐based polymer monomers. [ABSTRACT FROM AUTHOR]

BACKGROUND Biomass holds the promise to provide a sustainable future for the chemical industry. 2, 5‐Bishydroxymethylfuran (BHMF) is a versatile bio‐based diol with a broad range of potential applications in many polymeric materials, artificial fibers and drugs. However, the controlling of the BHMF selectivity in hydrogenation of biomass‐derived 5‐hydroxymethylfurfural (HMF) with complex transformation pathways is always a great challenge especially under solvent‐free conditions in which many side reactions may occur due to its rich reducible groups. RESULTS: A facile and effective approach was developed for the selective synthesis of BHMF by solvent‐free hydrogenation of a deep eutectic mixture consisting of HMF (75 wt%) and choline chloride (ChCl), by which a BHMF selectivity up to 94.6% was gained at full HMF conversion over Raney Co at 100 °C in 4 h. In addition, the HMF conversion and selectivity toward BHMF can be regulated and controlled through altering the strength of hydrogen‐bonding interactions of HMF‐based deep eutectic mixtures (ChCl–HMF mixtures). CONCLUSION: We developed an effective approach that allows the solvent‐free synthesis of BHMF via hydrogenation of HMF‐based deep eutectic mixtures. The extraordinary BHMF selectivity in the solvent‐free hydrogenation of HMF is reasonably attributed to the hydrogen‐bonding interactions formed between ChCl and HMF/BHMF which greatly suppresses the side reactions of HMF and the over‐reduction of BHMF. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND γ‐Valerolactone (GVL) is a versatile biomass‐derived platform molecule that could serve as a building block to produce chemicals, materials and fuels, but the production of GVL from biomass via a cost‐competitive method is challenging. In this contribution, a robust Cu─Mg oxide was prepared as an efficient bifunctional catalyst for both H2 production by MeOH reforming and hydrogenation of methyl levulinate (ML) to GVL in MeOH medium. RESULTS: Cu0.87Mg0.13Ox prepared by a urea hydrolysis method offered a GVL yield up to 90.6% at 220°C in 4 h without external hydrogen. This catalyst could be reused for at least seven consecutive cycles without loss of its activity. Notably, Cu0.87Mg0.13Ox also provided nearly 70% GVL yield in methanolysis products of cellulose in the presence of humins. Characterization of the catalyst indicates that the incorporation of MgO greatly facilitates the stabilization of Cu+ species that possess a better catalytic performance in ML hydrogenation compared with metallic Cu. CONCLUSION: This robust Cu0.87Mg0.13Ox could greatly contribute to develop a highly facile and desirable two‐step strategy for GVL production from cellulose, through the integration of ML production by methanolysis of cellulose, H2 formation by MeOH reforming and ML hydrogenation in MeOH medium. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: Although anionic surfactants have a distinct positive influence on the removal of particulate soil, the removal of particulate soils is insufficient in CO2 compared to perchloroethylene. A series of amino‐acid surfactants was selected as main surfactants to study the influence of polyoxyethylene ether and cosolvent on the cleaning effect. Glu‐C12 and C16(3) gave the best cleaning results, which increased from a detergency value of 4.6 when no surfactants were used to 8.32 when surfactants were used. In all experiments, charged anionic surfactant particles were formed, which are responsible for the removal of particulate soil from fabric by electrostatic repulsion. The use of a cosolvent (Isopropanol [IPA]) had a positive effect on the removal of particulate soil when using Glu‐C12 and TX‐45. However, for other compounding combinations, the addition of IPA had a negative effect on particulate soil removal. Of the cosolvents investigated, IPA was the most suitable. With the polarity of the system increasing after adding IPA, the ethylene oxide groups of TX‐45 were partially extended to CO2. Through the steric effects of branched methyl groups, the cleaning effect was improved. [ABSTRACT FROM AUTHOR]

Biomass‐derived di‐ethers, 2,5‐bis(alkoxymethyl)furans (BAMFs), are currently envisaged as promising biodiesel or additives. Herein, Zr‐SBA prepared by a urea hydrolysis method (Zr‐SBA‐UH) is used as a highly active bifunctional catalyst for the reductive etherification of 5‐hydroxymethylfurfural (HMF), and offers the 2,5‐bis(isopropoxymethyl)furan (BPMF) yield up to 93.6% using isopropanol as the solvent and hydrogen source. Zirconia is proved to be located mainly out of the mesoporous channels for Zr‐SBA‐UH, which leads to significant enhancement in the acid content of the catalyst, and then greatly promotes the catalytic performance of Zr‐SBA‐UH for the reductive etherification of HMF. The general soundness of Zr‐SBA‐UH in other monohydric alcohols is further confirmed in this contribution, guaranteeing that a family of BAMFs can be prepared by this catalytic system. In addition, Zr‐SBA‐UH is a robust catalyst that can be reused for at least five continuous runs without a significant loss of its catalytic activity. [ABSTRACT FROM AUTHOR]