The incompletely coordinated zinc ions in the concentrated aqueous ZnCl(2) solution catalyze the direct conversion of carbohydrates into 5-hydroxymethylfurfural, and a moderate HMF yield up to 50% can be achieved.

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.

By thermal treatment in vacuum, graphite oxide prepared from Hummers' method was exfoliated and partially reduced. This procedure imparts the graphene oxide (GO) the high reactivity with 2,2,6,6-tetramethyl-piperidin-1-oxyl (TEMPO) as co-catalyst for selective oxidation of 5-hydroxymethylfrufural (HMF) to 2, 5-diformylfuran (DFF) under certain conditions (100% HMF conversion with HMF selectivity 99.6% at 80 wt.% GO loading, 1 atm air pressure). This study found that GO could function as an oxidant for anaerobic oxidation of HMF during which carboxyl groups in GO were reduced. Importantly, the partially reduced GO material could continue activate molecular oxygen during aerobic oxidation. Further study showed that oxygen functionalities in GO material had a crucial effect on the catalytic oxidation of HMF.By control experiments and molecular analogues tests, a plausible mechanism was proposed in which the high reactivity was attributed to the synergistic effect of the carboxylic acid groups and unpaired electrons at GO edge defects, with TEMPO as the co-catalyst and oxygen as the terminal oxidant.

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A highly efficient and green process for the hydrogenation of biomass‐derived levulinic acid (LA) to γ‐valerolactone (GVL) has been developed. GVL was obtained in a yield of 99.9 mol % with a turnover frequency as high as 7676 h−1 in aqueous medium by using a Ru/TiO2 catalyst under mild reaction conditions (70 °C). The strong interaction between Ru and TiO2 facilitated both the dispersion of Ru nanoparticles and the stability of the catalyst. In addition, as solvent, water participated in the hydrogenation of LA, which was confirmed by an isotope‐ labeling experiment with D (D2O). Specifically, the H atom(s) in water took part in the hydrogenation of the CO group of LA, which promoted the catalytic activity and GVL yield remarkably.

An efficient strategy is developed for chemical recycling of cured epoxy resin (CEP) from its carbon fiber reinforced polymer composites (CFREP) using AlCl3/CH3COOH as the degradation system. Acetic acid swells the dense structures of CEP, facilitating the penetration of the aluminum ion catalyst into the polymer matrix. The weakly coordinating aluminum ions in CH3COOH solution selectively cleave the C–N bond while leaving the C–C, C–O (aryl alkyl ether) bonds intact. This process recovers valuable oligomers and carbon fibers from CFREP.

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Identification of the active copper species, and further illustration of the catalytic mechanism of Cu-based catalysts is still a challenge because of the mobility and evolution of Cu and Cu species in the reaction process. Thus, an unprecedentedly stable Cu-based catalyst was prepared by uniformly embedding Cu nanoparticles in a mesoporous silica shell allowing clarification of the catalytic roles of Cu and Cu in the dehydrogenation of methanol to methyl formate by combining isotope-labeling experiment, in situ spectroscopy, and DFT calculations. It is shown that Cu sites promote the cleavage of the O-H bond in methanol and of the C-H bond in the reaction intermediates CH O and H COOCH which is formed from CH O and HCHO, whereas Cu sites cause rapid decomposition of formaldehyde generated on the Cu sites into CO and H .