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Altered fructose tautomeric equilibria and following reverse-isomerization from fructose to glucose enabled a high lactic acid yield of 68.3 wt% over the “monolithic” Sn-beta catalyst, which is attributed to the non-thermal effect of microwave.

The wide application of melamine–formaldehyde resins (MFRs) in the food industry aggravates plastic pollution problems. Recycling of the waste MFRs remains a big challenge due to its compact structure. Herein, a high MFR degradation ratio of ca. 84 wt% was achieved under mild conditions (180 °C) in a methanesulfonic acid (MSA)–tetrahydrofuran (THF)–H2O system with cyanuric acid as the main degradation product. The SEM results showed that the degradation of MFRs followed different reaction mechanisms when H2O and THF were applied as solvents, respectively. The combination of the two solvents showed an obvious synergistic effect for the degradation of MFRs. The degradation experimental results with melamine as the model intermediate indicated that the degradation of MFRs proceeded via the selective cleavage of the sp2C–sp3N and sp3C–sp3N bonds to recover valuable C and N alternated-aromatic ring (CNAR) units, followed by their transformation into a valuable chemical of cyanuric acid.

A series of poly(ionic liquid)s (PILs) based on 1-vinyl-3-(3-sulfopropyl)imidazolium (VSpIm) and sodium p-styrenesulfonate (NaSS) have been successfully synthesized and fully characterized. The swelling behaviours of the PILs in 18 solvents with a wide range of Hansen solubility parameters (δT) were investigated. The PILs exhibited distinct swelling properties in solvents with δT > 24.5 MPa1/2, such as water, formamide and methanol. The molar swelling ratio (QM), which represented the swelling ability of the PILs in solvent, was linearly positively correlated with the δT value. Moreover, the enrichment behaviours of the PILs in various mixed solvents were also studied. In water/solvent and formamide/solvent monophasic mixed solvents, the enrichment factors of the PILs to water and formamide were up to 39.82 (water/THF) and 17.69 (formamide/THF), respectively. The enrichment factor of the PILs to water (or formamide) was linearly positively correlated with the difference between δT (water) (or δT (formamide)) and δT (solvent). The excellent swelling and enrichment properties of the PILs in solvents were attributed to the strong interactions between the PILs and solvent molecules, especially the hydrogen-bonding interactions, which was supported by nuclear magnetic resonance (NMR) spectroscopy. Furthermore, a PIL was used as a catalyst for the hydration of alkyne and found that it had higher catalytic activity than those of both heterogeneous and homogeneous catalysts.

Deep eutectic solvents (DESs) have attracted considerable attention due to their unique properties. Owing to similar structures and properties, DESs are also called "quasi-ionic liquids" or "ionic liquid analogous". However, for a deeper understanding and application of DESs, a comprehensive investigation on the ionicity of DESs is crucial. In this work, the effects of the structure and components of typical DESs on the ionicity were investigated. Moreover, the ionicity was discussed by using Walden plot, and the validity of applying it to DESs was verified using pulsed field gradient nuclear magnetic resonance (PFG-NMR). We found that the lack of free charged species and high viscosities make it difficult to achieve optimal conductivities for DESs, and thus most of them exhibit "poor ionic" nature. Fortunately, with an in-depth understanding of its microstructure and physicochemical properties, the properties of DESs can be finely tailored by selecting or even designing suitable parent compounds for functional applications. In particular, the ionicity of Li-based DESs was investigated for their potential application as electrolytes in Li-ion batteries.

The existing triacetylglycerol (TAG) production method involves esterification of oil (fat)-derived glycerol with acetic acid, forming a mixture of mono-, di- and tri- acetylglycerols. Herein, a new acyl exchange reaction is developed to directly and efficiently produce TAG from waste oils and fats by the driving effect of substituent size changes. Small-sized acetic acids easily replace large long-chain fatty acids of oils. This release in the intramolecular tension and diminishing of steric hindrance make TAG both thermodynamically and dynamically the most favorable product. Pure TAG was obtained with a high yield of 94.9%.

A well-defined nitro group functionalized porous aromatic framework (NO2-PAF-1) was synthesized via a bottom-up strategy using a copper-mediated Ullmann reaction. The synthetic route is cost-efficient and robust for large scale preparation. The Brunauer–Emmett–Teller (BET) specific surface area of the obtained NO2-PAF-1 is up to 610 cm2 g−1 with micro/mesoporosity. Its CO2 uptake was measured to be higher than that of PAF-1 due to the strong interaction between the nitro groups and CO2 molecules, proven by the enhanced isosteric heat of CO2 adsorption (38.4 kJ mol−1).

Compared to 5-HMF (C6H6O3), angelica lactone (C5H6O2) is a platform compound that has more potential for biomass-derived high performance bio-alkane fuel production due to a CC bond in the molecular structure, leading to a C–C coupling intermediate (C10 self-aggregation dimer) and higher C:O ratio (2.5), resulting in lower hydrogen consumption for the subsequent hydrodeoxygenation process. Biomass-derived levulinic acid was used as the only starting raw material to produce C10 branched alkanes. First, carboxyl and carbonyl functional groups of levulinic acid under catalysis via intramolecular esterification and dehydration yielded angelica lactone, which included two isomers of angelica lactone (α-angelica lactone and β-angelica lactone). Secondly, angelica lactone di/trimers would be obtained by angelica lactone self-aggregation: α-angelica lactone and β-angelica lactone connecting via C–C bond coupling. Finally, these intermediate products are selectively hydrodeoxygenated over a RANEY® catalyst to obtain C7–C10 branched alkanes. Nearly a 90% yield can be achieved under 483 K and 5 MPa H2 and the C10 branched alkane product, 3-ethyl-4-methyl heptane, accounts for 75% of the same.

Low temperature 1H- and 19F-DOSY have been used for analyzing reactive intermediates in glycosylation reactions, where a glycosyl trichloroacetimidate donor has been activated using different catalysts. The DOSY protocols have been optimized for low temperature experiments and provided new insight into acid catalyzed glycosylation chemistry. From the study a new glycosylation intermediate was characterized.

The basic ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) could efficiently catalyze the conversion of 2-amino-2-deoxy-d-glucose (GlcNH2) into deoxyfructosazine (DOF) and fructosazine (FZ). Mechanistic investigation by NMR studies disclosed that [C2C1Im][OAc], exhibiting strong hydrogen bonding basicity, could coordinate with the hydroxyl and amino groups of GlcNH2via the promotion of hydrogen bonding in bifunctional activation of substrates and further catalyzing product formation, based on which a plausible reaction pathway involved in this homogeneous base-catalyzed reaction was proposed. Hydrogen bonding as an activation force, therefore, is responsible for the remarkable selectivity and rate enhancement observed.

An efficient strategy has been developed for chemical recycling of unsaturated polyester resin (UPR) and its glass fibre reinforced polymer composites (GFRP) by selectively cleaving C–O bonds using the AlCl3/CH3COOH system. AlCl3 promotes acyl exchange reaction between CH3COOH and UPR. This process facilitates recovery of valuable oligomers and monomers from UPR, and glass fibres from GFRP.

The incompletely coordinated zinc ions in water enable the cleavage of R2C(secondary carbon)–N bonds without breaking the C–O (aromatic ether) and C–C bonds in carbon fiber/epoxy resin composites. This selective cleavage of C–N bonds favors the recovery of valuable carbon fiber and the basic carbon unit of epoxy resin from their waste composites.

An efficient one-pot dehydration process for convert D-glucosamine hydrochloride (GlcNH2) into 2-(D-arabino-1′,2′,3′,4′-tetrahydroxybutyl)-5-(D-erythro-2′′,3′′,4′′-trihydroxybutyl)pyrazine (deoxyfructosazine, DOF) and 2,5-bis-(D-arabino-1,2,3,4-tetrahydroxybutyl)pyrazine (fructosazine, FZ) was reported. A task-specific basic ionic liquid, 1-butyl-3-methylimidazolium hydroxide ([BMIM]OH), was employed as an environmentally-friendly solvent and catalyst. The products were qualitatively and quantitatively characterized by MALDI-TOF-MS, 1H NMR and 13C NMR spectroscopy. The influences of GlcNH2 concentrations, reaction temperature, reaction time, additives and co-solvents on the yields of products were studied. The maximum yield of 49% was obtained in the presence of [BMIM]OH and DMSO under optimized conditions (120 °C, 180 min). In addition, a plausible mechanism was proposed. Our project was to develop efficient, atom economical and eco-compatible routes for the synthesis of heterocyclic compounds from marine biomass (or nitrogen-containing biomass). The obtained aromatic heterocyclic compounds showed potential pharmacological action and physiological effects, and they also could be utilized as flavoring agents in the food industry.

Graphene oxide obtained by the Hummers method was discovered to be an efficient and recyclable acid catalyst for the conversion of fructose-based biopolymers into 5-ethoxymethylfurfural (EMF). EMF yields of 92%, 71%, 34% and 66% were achieved when 5-hydroxymethylfurfural (HMF), fructose, sucrose and inulin were used as starting materials, respectively.