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A robust and completely heterogeneous catalyst, Pd/Hf-MMT, was highly efficient for reductive aminolysis of aryl ethers to producce N-cyclohexyl-substituted amines at a low H2 pressure of 0.3 MPa without using any homogeneous acidic additives.

The sustainable route for δ-lactam (6-methylpiperidin-2-one: MPO) production has been demonstrated through transfer hydrogenation/hydrogenolysis of aminolysis product of biomass-derived triacetic acid lactone (TAL) with bimetallic Ni-Ru catalyst.

A NbOx catalyst with oxygen vacancies is synthesized and used for nitrate electroreduction to ammonia. The faradaic efficiency of 94.5% and the NH3 formation rate of 55.0 μg h−1 mgcat−1 can be achieved in a neutral electrolyte.

This work describes the highly efficient Pd-catalyzed direct coupling of aryl ethers (including the typical lignin model compounds) and morpholines to produce 4-cyclohexylmorpholines, a useful class of fine chemicals. Without employing any acidic additives, various 4-cyclohexylmorpholines could be synthesized with good yields from a variety of aryl ethers using H2 as a hydrogen resource. A mechanism study revealed that the desired product was formed via the cleavage of the C(Ar)–O bonds to generate the corresponding cyclohexanones and subsequent reductive amination.

The transformation of renewable lignin-based platform chemicals into value-added nitrogen-containing compounds is an emerging strategy for lignin utilization. However, multi-reactive sites on these platform chemicals make it challenging to control the product selectivity, thereby resulting in limited success. In this work, we developed the reductive-coupling of guaiacol, a typical lignin-based platform chemical, with amines and H2 to synthesize methoxy-functionalized cyclohexylamines. It was demonstrated that Pd/C was a very efficient catalyst for this kind of reaction, and high yields of the target products can be obtained. Notably, this methodology can be applied for the reductive-coupling of various guaiacol analogues with amines to synthesize alkoxyl-functionalized cyclohexylamines with high yields. A mechanism study revealed that the reaction occurred through the generation of 2-methoxycyclohexanone and its subsequent reductive amination.

Bi2WO6 nanosheets with plentiful oxygen vacancies were synthesised, and were highly efficient for the electroredution of CO2 to CO. The faradaic efficiency of CO could reach 91% with a high current density of 43 mA cm−2 at low potentials. The oxygen vacancies could enhance the reaction effectively by improving the adsorption and activation of CO2.

To produce aromatic hydrocarbons from biomass, a novel route is reported for one-pot selective hydrodeoxygenation of a lignin derived aryl ether mixture to C6–C9 aromatic hydrocarbons over Ru/sulfate zirconia in the aqueous phase. The cascade steps undergo the initial precise cleavage of the Caliphatic–O bond of phenolic dimers or Caromatic–OCH3 of phenolic monomers, as well as the full blockage of benzene-ring and cyclic-alkene hydrogenation to realize nearly quantitative aromatic hydrocarbon formation at 240 °C in the presence of low pressurized H2 (2–8 bar). With a Ru catalyst, the primary and competitive steps in hydrogenolysis of the C–O bond and hydrogenation of the benzene ring are shown to be sensitive to temperature and hydrogen pressure, which can subtly modify the concentration and spatial distribution of the surface adsorbed H˙. A high temperature and a low hydrogen pressure are found to be essential for hydrogenolysis, since the H˙ species nearby the oxygen atom are more strongly adsorbed under such conditions and thus preferred to be retained on the Ru surface. Herein it is defined as the “atom-induced H sorption effect”, probably resulting from the analogous hydrogen-bond force between the adsorbed H˙ and the adjacent oxygen atom on the metal surface. Besides the initial step, another key point for aromatic hydrocarbon formation is to optimize the target route of cycloalkene dehydrogenation, but suppress the parallel hydrogenation pathway to saturated cycloalkanes. It is found that the produced phenol intermediate serves as a suitable H-acceptor for the selected catalytic system during the whole conversion, via fast consumption of the in situ produced H˙ from cyclohexene dehydrogenation. Such an interesting phenomenon of internal hydrogen transfer not only promotes the dehydrogenation and hydrogenation equilibrium of cyclohexene but also lowers the in situ H˙ concentration on the Ru surface, both of which would be beneficial for reaching a high benzene yield. This hypothesis for internal hydrogen transfer is further confirmed by separate experiments and density functional theory modelling results.

Ionic liquids (ILs) have numerous applications in industrial processes as a benign alternative to conventional volatile organic solvents. However, many of them are toxic to organisms and are poorly biodegradable. In this work, a series of environmentally friendly cholinium ILs have been designed and synthesized. It was found that these ILs could form aqueous two-phase systems (ATPSs) with polypropylene glycol 400 (PPG400) which is thermo-sensitive, non-toxic and biodegradable. In order to understand the phase formation processes and possible application of these ATPSs for extraction/separation of proteins, the binodal curves and tie lines of these ATPSs were measured at 25 °C, and the effects of anionic structure of the ionic liquids, nature of the proteins and difference in the concentration of top- and bottom-phases on the partitioning behavior of some typical proteins were investigated systematically. It was shown that bovine serum albumin (BSA), trypsin, papain and lysozyme could be enriched effectively into the ionic liquid-rich phase of the ATPSs, and single-step extraction efficiency could be as high as 86.4–99.9% under the optimized conditions. Furthermore, enzyme activity of the native trypsin in water and in aqueous ionic liquid solutions was determined by using N-a-benzoyl-L-arginine ethyl ester as a substrate, and activity increases to about 127% was observed after 13 months storage. In addition, PPG400 has been recovered simply by heating and reused in the next extraction processes. This avoids the non-sustainable issue of highly salty water produced in the application of the polyethylene glycol (PEG) + salt and ionic liquid + salt ATPSs.

Esterification of carboxylic acids with alcohols could be carried out in a Bronsted acidic ionic liquid 1-methylimidazolium tetrafluoroborate ([Hmim]+BF4−). Good yields were obtained, and the esters produced could be easily separated from the reaction mixture without any volatile organic solvents. The ionic liquid [Hmim]+BF4− could be reused after removal of water.