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Electrocatalytic CO2 reduction is a typical reaction involving two reactants (CO2 and H2O). However, the role of H2O dissociation, which provides active *H species to multiple protonation steps, is usually overlooked. Herein, we construct a dual-active sites catalyst comprising atomic Cu sites and Cu nanoparticles supported on N-doped carbon matrix. Efficient electrosynthesis of multi-carbon products is achieved with Faradaic efficiency approaching 75.4% with a partial current density of 289.2 mA cm−2 at −0.6 V. Experimental and theoretical studies reveal that Cu nanoparticles facilitate the C-C coupling step through *CHO dimerization, while the atomic Cu sites boost H2O dissociation to form *H. The generated *H migrate to Cu nanoparticles and modulate the *H coverage on Cu NPs, and thus promote *CO-to-*CHO. The dual-active sites effect of Cu single-sites and Cu nanoparticles gives rise to the catalytic performance. A dual-site catalyst consisting of Cu nanoparticles (NPs) and atomic Cu sites is designed. The atomic Cu boosts H2O dissociation for modulating the *H coverage on Cu NPs, improving the efficiency of CO2 electroreduction to multi-carbon products. [ABSTRACT FROM AUTHOR]

Effective valorization of lignin to produce high-value chemical products can enhance the productivity and profitability of biorefineries. The upgrading of lignin derived molecules such as phenols into high-value commodity chemicals is an effective way to combine low environmental footprint with significant economic benefits. Selective O-acylation of phenolic compounds to produce phenolic esters which possess diverse applications is very attractive. Herein, we report an efficient, convenient one-pot method for selective O-acylation of phenols at room temperature in air. For the first time, abundant, safe, stable organic salts are used as acylating reagents. The reaction was mediated by diethylaminosulfur trifluoride (DAST) which simultaneously acted as an activator for phenols and deoxyfluorination reagent for organic salts. Phenolic esters were almost quantitatively produced from a diverse range of phenols including lignin-derived substrates. This new method is significantly distinct from existing routes, and the scientific discovery about activation of phenolic hydroxyl groups is instructive for exploration of new chemical reactions. [ABSTRACT FROM AUTHOR]

It is very interesting to synthesize high value-added chemicals from CO2 under mild conditions with low energy consumption. Here, we report that a novel catalyst, Zn(betaine)2Br2, can efficiently promote the cycloaddition of CO2 with epoxides to synthesize cyclic carbonates under ambient conditions (30 °C, 1 atm). DFT calculations provide important insights into the mechanism, particularly the unusual synergistic catalytic action of Zn2+, Br− and NR4+, which is the critical factor for the outstanding performance of Zn(betaine)2Br2. The unique features of the catalyst are that it is cheap, green and very easy to prepare. [ABSTRACT FROM AUTHOR]

Electrochemical reaction of CO2 and water to produce valuable chemicals and fuels is of great importance. Producing syngas with tunable CO/H2 ratios and high current density is an interesting topic. In this work, Zn films with different morphologies and wettability were fabricated. It was demonstrated that Zn films could be used as efficient electrocatalysts for CO2 reduction to syngas and the CO/H2 ratios could be controlled in the range of 0.09–11.4 changing the morphology and wettability of the catalysts and the applied potential. Particularly, using the nanoleaf Zn film with a water contact angle of 91° as the electrode, the current density could reach 90.4 mA cm−2 with a CO/H2 ratio of 1/1 at −1.27 V vs. RHE. In addition, the maximum FE of CO could reach 92.6% with a current density of 35.3 mA cm−2 at a low overpotential of 440 mV. Detailed studies reveal that the three-dimensional electrode architecture and suitable wettability were favorable for CO2/H+ mass transfer and charge transfer, which are important factors for achieving efficiency. [ABSTRACT FROM AUTHOR]

Co nanoparticles supported on N,B-co-doped graphitic carbon exhibited efficient electrocatalytic activity towards the transformation of CO2 to CO with a faradaic efficiency of 97.9% and a current density of 18.8 mA cm−2, which is the highest current density at high FE over Co-based catalysts in an H-cell. The ratio of CO to H2 can be adjusted by changing the amount of B doping. The excellent performance of the catalyst is mainly due to its favorable electron density configuration, larger electrochemical surface area, and higher conductivity. [ABSTRACT FROM AUTHOR]

Piperidine and δ‐Lactam chemicals have wide application, which are currently produced from fossil resource in industry. Production of this kind of chemicals from lignocellulosic biomass is of great importance, but is challenging and the reported routes give low yield. Herein, we demonstrate the strategy to synthesize 2‐methyl piperidine (MP) and 6‐methylpiperidin‐2‐one (MPO) from biomass‐derived triacetic acid lactone (TAL) that is produced microbially from glucose. In this route, TAL was firstly converted into 4‐hydroxy‐6‐methylpyridin‐2(1H)‐one (HMPO) through facile aminolysis, subsequently HMPO was selectively transformed into MP or MPO over Ru catalysts supported on beta zeolite (Ru/BEA‐X, X is the molar ratio of Si to Al) via the tandem reaction. It was found that the yield of MP could reach 76.5 % over Ru/BEA‐60 in t‐BuOH, and the yield of MPO could be 78.5 % in dioxane. Systematic studies reveal that the excellent catalytic performance of Ru/BEA‐60 was closely correlated with the cooperative effects between active metal and acidic zeolite with large pore geometries. The related reaction pathway was studied on the basis of control experiments. [ABSTRACT FROM AUTHOR]

The Meerwein–Ponndorf–Verley (MPV) reaction is an attractive approach to selectively reduce carbonyl groups, and the design of advanced catalysts is the key for these kinds of interesting reactions. Herein, we fabricated a novel zirconium organoborate using 1,4-benzenediboronic acid (BDB) as the precursor for MPV reduction. The prepared Zr-BDB had excellent catalytic performance for the MPV reduction of various biomass-derived carbonyl compounds (i.e., levulinate esters, aldehydes and ketones). More importantly, the number of borate groups on the ligands significantly affected the catalytic activity of the Zr-organic ligand hybrids, owing to the activation role of borate groups on hydroxyl groups in the hydrogen source. Detailed investigations revealed that the excellent performance of Zr-BDB was contributed by the synergetic effect of Zr4+ and borate. Notably, this is the first work to enhance the activity of Zr-based catalysts in MPV reactions using borate groups. [ABSTRACT FROM AUTHOR]

We herein report Cu mediated side-directed dehydroxyalkylative halogenation of aryl alcohols. C(aryl)–C bonds of aryl alcohols were effectively cleaved, affording the corresponding aryl chlorides, bromides and iodides in excellent yields. Aryl alcohols could serve as both aromatic electrophilic and radical synthetic equivalents during the reaction. [ABSTRACT FROM AUTHOR]

The electrochemical oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is a highly attractive strategy to generate valuable biomass-based oxygenated chemicals. Robust, stable and inexpensive electrocatalysts are crucial for this interesting reaction. In this work, we found that the electrocatalytic performance of cobalt oxide (CoO) could be significantly improved by introducing oxygen vacancies via Se doping. The resulting CoO-CoSe2 with a CoO/CoSe2 molar ratio of 23 : 1 showed excellent performance and stability for the electro-oxidation of HMF to FDCA, and a FDCA yield of 99% could be achieved with a faradaic efficiency of 97.9% at a potential of 1.43 V vs. RHE. A systematic study indicates that the introduction of rich oxygen vacancies could enhance the catalytic activity and the selectivity to FDCA by increasing the electrochemical surface area and reducing charge transfer resistance. As far as we know, this is the first work to develop a highly stable metal oxide as the active component for this reaction. [ABSTRACT FROM AUTHOR]

Expression levels and significance of miR-184 and miR-126 in burned rats were investigated. A total of 30 healthy rats were selected to construct a burn rat model, and another 10 healthy rats as the control group. The modeled rats were divided into groups I, II and III according to burn area, 10 for each group. The reverse transcription-quantitative polymerase chain reaction (RT-q.PCR) was used to detect the expression of miR-184 and miR-126 in the serum of three groups of burned rats, and ELISA was employed to detect the expression levels in peripheral blood and the correlation. There was no difference in the expression levels of miR-184 and miR-126 among the four groups of rats before modeling (P>0.05). Those of miR-184 and miR-126 at each time point were lower than those at the previous one in groups I, II and III (P<0.05). There was no significant change in the expression levels of miR-184 and miR-126 in the control group (P>0.05). At the same time point, those of miR-184 and miR-126 decreased with the increase of burn degree, and the difference was statistically significant between every two groups (P<0.05). The results of Pearson's correlation analysis revealed that the expression level of miR-184 was positively correlated with that of miR-126 (r=0.832, P=0.002). miR-184 and miR-126 were positively correlated with burn degree (r=0.901, P=0.001, r=0.775, P=0.001) and time after burn (r=0.732, P=0.004, r=0.753, P=0.002). The expression levels of miR-184 and miR-126 decrease in burned rats. The changes of their levels may be used as a reference standard for clinical efficacy evaluation to evaluate burn degree, preventing burn wounds from deepening. [ABSTRACT FROM AUTHOR]

Novel porous TiO2@Cu3(BTC)2 composites, which were synthesized using ionic liquids (ILs) as solvents, exhibited excellent activity for photooxidation of styrene to 4-aryl tetralones and promoting the Glaser coupling reaction with O2 under light irradiation. It was discovered that the transformation between Cu2+ and Cu+ was crucial for enhancing the photocatalytic performance. [ABSTRACT FROM AUTHOR]

The biodiesel production process generates a significant amount of glycerol as a byproduct. A drive to add value has attracted worldwide attention, with the aim of improving the overall effectiveness and profitability of biodiesel production. Herein, we report hydroxyapatite (HAP)-supported Ru-Zn-CuI (Ru-Zn-CuI/HAP) as effective catalysts for the transformation of glycerol to lactic acid (LA).The catalysts were characterized by using different techniques. The effects of catalyst composition, reaction time, and temperature on the conversion and product distribution were investigated. It was revealed that Ru nanoparticles of less than 2 nm were dispersed uniformly on HAP. CuI could effectively inhibit the cleavage of C−C bonds, which led to improved yields of LA. Under optimized conditions, the yield of LA could reach 70.9 % over Ru-Zn-CuI/HAP. Furthermore, the catalyst could be reused at least four times without an obvious loss of activity or selectivity. [ABSTRACT FROM AUTHOR]

The highly selective aerobic oxidation of cyclohexane to cyclohexanone and cyclohexanol (KA-oil) under benign and green conditions is still a challenging topic. In this work, V2O5@TiO2 catalysts were prepared by V species deposited on TiO2 (P25) and characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), and UV-vis diffuse reflectance techniques. The selective aerobic oxidation of cyclohexane was carried out over V2O5@TiO2 catalysts with oxygen as an oxidant under simulated light irradiation. The influences of solvents, metals and mass of V species deposited on TiO2, pressure of oxygen, and reaction time on the reaction were investigated. It was found that the V species deposited on the TiO2 surface was very efficient for the photocatalytic oxidation of cyclohexane under simulated solar light irradiation. More interestingly, the selectivity of the reaction in an acetonitrile/water mixed solvent was much higher than that in other solvents. Under the optimized conditions, the selectivity to KA-oil products could be nearly 100% at a cyclohexane conversion of 18.9%. The possible pathway for the catalytic reaction was proposed. [ABSTRACT FROM AUTHOR]

2,5-Dimethylfuran (DMF) is an important candidate for liquid fuels and can be produced from biomass derived 5-hydroxymethylfurfural (HMF). Efficient transformation of HMF to DMF has not been achieved over a non-noble catalyst under milder conditions. Herein, we developed a copper and cobalt bimetallic nanoparticle catalyst supported on N-graphene-modified Al2O3 (CuCo®/NGr/α-Al2O3). It was found that CuCo®/NGr/α-Al2O3 could catalyze the conversion of HMF to DMF effectively and the yield of DMF could reach 99%. The catalyst was completely not active for the hydrogenation of the C=C bond in furan and thus no 2,5-bis(hydroxymethyl)tetrahydrofuran (DHTHF) and 2,5-dimethyltetrahydrofuran (DMTHF) were detected. [ABSTRACT FROM AUTHOR]

Herein we propose for the first time the utilization of a metal complex for forming water-in-supercritical CO2 (scCO2) microemulsions. The water solubility in the metal-complex-stabilized microemulsion is significantly improved compared with the conventional water-in-scCO2 microemulsions stabilized by hydrocarbons. Such a microemulsion provides a promising route for the in situ CO2 reduction catalyzed by a metal complex at the water/scCO2 interface. [ABSTRACT FROM AUTHOR]

The preparation of functional materials and value-added chemicals using biomass-derived feedstocks is an interesting topic. Herein, we propose a method to prepare Ru/graphene catalyst using glucose as the carbon source. The catalyst was characterized by scanning and transmission electron microscopies, Raman and X-ray photoelectron spectroscopies, and X-ray diffraction. It was found that Ru particles of 2-6 nm were supported uniformly on high-quality graphene. The performance of the Ru/graphene for hydrogenation of levulinic acid to γ-valerolactone was studied. The Ru/graphene had much higher activity for the hydrogenation reaction than commercial Ru/C, and was active even at room temperature. The high activity was partially due to the unique structure of graphene, which resulted in an electron-enriched Ru nanocatalyst. In addition, the Ru/graphene could be reused at least four times without considerable decrease in activity, indicating the excellent stability of the catalyst under our conditions. [ABSTRACT FROM AUTHOR]

Both the selective conversion of glucose into arabinose and the reduction of nitrosobenzene to azoxybenzene are very important but challenging processes. Herein we carried out the first work on the simultaneous transformation of glucose to arabinose and of nitrosobenzene to azoxybenzene by photocatalysis. It was found that Pd nanoparticles supported on mesoporous CdS were very active and selective for the reactions in water under visible light irradiation. Nitrosobenzene could be reduced to azoxybenzene with a selectivity of 92% by hydrogen from water and glucose. More importantly, glucose was oxidized to arabinose with high selectivity (70%) by photoexcited holes. The reaction mechanism and the reason for the high selectivity were studied using control experiments. [ABSTRACT FROM AUTHOR]

Supported vanadium oxides (V xO y) on hydrophobic poly(ionic liquid)s (PILs), for which the PILs were obtained by copolymerization of the ionic liquid (IL) 1-hexadecyl-3-vinylimidazolium bromide and the cross-linker divinylbenzene (DVB), are reported. The V xO y/PIL catalyst was characterized by different techniques, and the performance of the catalyst for the selective oxidation of benzene to phenol was studied with H2O2 as the oxidant. It was demonstrated that V xO y/PIL had much better catalytic performance than the analogous catalyst V xO y/P, prepared with the polymer support (P) obtained from DVB and vinyl imidazole, without the IL. The high activity and selectivity of the V xO y/PIL catalyst could be attributed to the incorporation of the IL during the polymerization, which endowed the V xO y/PIL catalyst with increased specific surface area, stronger absorbent ability, and more active sites than the smooth and bulky V xO y/P. Furthermore, the hydrophobic side chain of the IL in the catalyst was beneficial for the access of benzene and the removal of the generated phenol from the surface of the catalyst, which also played an important role in improving the catalytic performance of V xO y/PIL. Up to 13.4 % yield of phenol was achieved, with a high selectivity of 97.5 %. In addition, the catalyst could be easily separated and recycled at least three times without significant decline in the phenol yield. [ABSTRACT FROM AUTHOR]

Transformation of anisole (methoxybenzene), a typical component of bio-oil, into phenol and methylated phenols was studied over HY zeolites with framework Si/Al ratios of 5, 15, 25, and 35. It was demonstrated that the amounts of Brønsted acid and Lewis acid sites, the ratio of Lewis acid and Brønsted acid sites, and the textural properties of the zeolites were all crucial parameters that influenced the catalytic performance. The Brønsted acid and Lewis acid sites of the zeolites catalyzed the reaction cooperatively and efficiently promoted the transmethylation. The hierarchical channel system with fully open micropore-mesopore connectivity was favorable to reduce the amount of coke generated. [ABSTRACT FROM AUTHOR]

Herein it was found that gas can be utilized as an activator to promote metal–organic framework (MOF) crystallization in IL at room temperature. The ultra-small MOF nanoparticles were obtained, and their size and porosity properties can be easily modulated by controlling gas pressure. The as-synthesized nano-sized Cu-MOF is an excellent candidate catalyst for the solvent-free oxidation of cyclohexene with oxygen. [ABSTRACT FROM AUTHOR]