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Bi2WO6 with double active sites of tunable metallic Bi and oxygen vacancies is constructed to achieve the highly efficient and selective photocatalytic oxidation of cyclohexane with air under solvent-free conditions.

Thermal-responsive hydrogel actuators have aroused a wide scope of research interest and have been extensively studied. However, their actuating behaviors are usually monotonous due to their unchangeable shapes and structures. Here, we report thermal-responsive poly(isopropylacrylamide

Oxygen-containing organics, which are generated from the selective oxidation of their corresponding hydrocarbons, have high value in the chemical and pharmaceutical industries. However, their oxidation reactions are very challenging as the products are more active than the substrates, especially for the oxidation of cyclohexane (CHA). Herein, we focused on the one-step preparation of Bi

BiOI nanosheets could catalyze the photothermal catalytic CO2 oxidative dehydrogenation of propane to propylene.

A self-propagated carbonization method to prepare phosphorus-doped carbon materials has been developed.

Benzyl alcohol can exclusively yield 99.8% benzaldehyde over a Z-scheme heterojunction photocatalyst of ZnO/C3N4 under solvent-free aerobic photocatalytic oxidation conditions.

A Cu–Zr bimetallic catalyst could achieve CO2RR to ethylene in aqueous electrolytes via the interface between Cu and Zr species.

Although the oxidative dehydrogenation of propane with CO2 (CO2-ODP) is a sustainable route for producing propylene with the tandem conversion of CO2 to the value-added CO, its industrialization is...

A solvothermal route was developed to synthesize hierarchical TiO2 nanoflowers with tunable morphology, macroporous and mesoporous structure, and larger surface areas by varying the ratio of N,N-dimethylformamide to isopropyl alcohol without using surfactant and template. Morphology and microstructure, textural, crystalline, optical and photoelectric properties were characterized to investigate thoroughly the correlation of features and photoactivity of catalysts. The photoactivity was evaluated for the degradation of phenol through analyzing the phenolic compounds. The catalysts exhibited significantly high photocatalytic activity with the degradation rate of phenol of 95%, and the decrease of total organic carbon (TOC) was 82 ± 3% under ultraviolet radiation (UV) for 180 min at room temperature. Meanwhile, the excellent cyclic stability and regenerability were obtained during five cycles and continued illumination. The enhanced photocatalytic activity probably was attributed to larger surface areas, hierarchical porous structure, effective generation and separation of the charge carriers, and outstanding light-harvesting ability.

Hydrogel shape memory and actuating functionalities are heavily pursued and have found great potential in various application fields. However, their combination for more flexible and complicated morphing behaviors is still challenging. Here they report that by controlling the light-initiated polymerization of active hydrogel layers on shape memory hydrogel substrates, advanced morphing behaviors based on programmable hydrogel shapes and actuating trajectories are realized. The formation and photo-reduction-induced dissociation of Fe

Dehydrogenation of propane in the presence of CO2 (CO2-ODHP) is an important route for the synthesis of propylene and utilization of the waste CO2. In the present work, diverse GaN supported on NaZ...

Hydrogenolysis of biomass-derived lignin sources is highly important for the conversion of renewable biomass resources to biofuels. However, lots of developed catalysts suffer from the drawbacks of expensive precious metal catalysts and/or operation under harsh conditions. In the present work, Co–Ni bimetallic catalysts were prepared and applied in catalyzing hydrogenolysis of Caryl–O aromatic ethers with high activities under the promotion of Nb2C MXene additive. Especially, the hydrogenolysis of diphenyl ether (DPE), a 4–O–5 model compound, to cyclohexane (cy) and cyclohexyl alcohol (cy-ol) could be achieved over the Co2Ni1Ox–Nb2C MXene catalytic system at 120 °C and under 5 bar of H2, which are mild conditions in comparison with those for the developed heterogeneous precious-metal-free catalysts. The excellent catalytic performances stemmed from the strong interaction between Co and Ni species and the promotion of Lewis acidic sites offered by Nb2C MXene. The proposed reaction pathway involved the direct hydrogenolysis of DPE route, in which DPE was initially hydrogenolyzed to benzene and phenol. They were further hydrogenated to cy and cy-ol. The present work not only develops a noble-metal-free bimetallic catalyst for utilization of biomass-derived lignin sources, but also provides a novel strategy for using the Nb2C MXene material.

Photocatalytic CO2 reduction is a highly vital process for converting CO2 into valuable chemicals. However, the reaction always proceeds less efficaciously at low temperature. A combination of optical and thermal conditions is one of the feasible approaches to achieve the reaction with high efficiency and has gained much attention recently. In the present work, we prepared several Co–Cu–Mn trimetallic catalysts via a simple co-precipitation method, which were used in catalyzing photothermal CO2 reduction to hydrocarbons. The metal composition and reduction temperature of the catalysts had important effects on their structural and photoelectrical characteristics and adsorption behaviors, further resulting in diverse catalytic performances. Among the prepared trimetallic catalysts, Co7Cu1Mn1Ox(200), with a Co/Cu/Mn molar ratio of 7/1/1 and reduced at 200 °C in H2 for 2 h, could produce CH4 with an activity of 14.5 mmol gcat−1 h−1 in 10% CO2/30% H2/60% N2, and CH4 and C2+ hydrocarbons with the activities of 15.9 and 7.5 mmol gcat−1 h−1 in 25% CO2/75% H2, respectively. The present strategy for constructing trimetallic oxide catalysts for the photothermal reaction not only provides a highly active catalyst for CO2 utilization, but also offers a potential possibility for reducing the high temperature of conventional thermal reactions.

Drug-loaded micelles for oral administration are desired for its convenience, low cost and flexibility, but current designs rely on introducing pH responsiveness, leaving problems like drug leakage and low accuracy of targeted delivery un-solved. Herein, we reported an acid-resistant ROS-responsive hyperbranched polythioether which can self-assemble into micellar structure and pass through the gastrointestinal tract without leaking drugs. At the inflammatory lesions, the thioester bonds are oxidized to sulphone groups to significantly increase the hydrophilicity in response to accumulated ROS species and efficiently release the encapsulated drugs. Animal experiments, including the evaluation of bodyweight, colon length, MPO activity, spleen index, histology and quantitative reverse transcription PCR, evidenced that the drug-loaded micelles have improved therapeutic efficiency compared to bare drug administration for the treatment of DSS-induced colitis in mice. This study provides an example of oral administrated micellar system can be extended for the treatment of other intestinal tract diseases.

We propose a new strategy to make an active and stable Ni-based catalyst which can be operated in a wide range of reaction temperatures. The ordered mesoporous alumina (OMA) with confined Ni in the pore wall (Ni-OMA) was prepared via the one-pot evaporation induced self-assembly method. By using the incipient impregnation method, different amounts of free Ni were loaded over Ni-OMA (Ni/Ni-OMA) at a fixed total NiO content of 15 wt%. Characterization results confirmed the formation of well-structured Ni-OMA, and the ordered structure was still well preserved even after impregnating NiO at a content of as high as 12 wt%. The catalysts were evaluated for the CO methanation as a model reaction under varied conditions. Importantly, the activity and stability of Ni/Ni-OMA for the titled reaction were significantly regulated by simply changing the ratio of the confined to free Ni. Over the optimum catalyst of NiO (2 wt%)/NiO (13 wt%)-OMA, the high activity at a temperature of as low as 300 °C was achieved with the space-time yield of methane over 7.6 g gcat−1 h−1 while a long-term stability for a time-on-stream of 400 h was confirmed without an observable deactivation under the conditions of 600 °C and an extremely high gas hourly space velocity of 120,000 mL g−1 h−1. The results were well explained as the integrated merits of the free Ni for a high dispersion and the confined Ni in OMA for the anti-sintering property.

Catalytic conversion of CO2 into methanol is of particular interest as it does not only provide valuable methanol, but also utilize the waste CO2. In the present work, a CoO/Co/TiO2 catalyst was developed and utilized in catalyzing CO2 to methanol under photothermal conditions. From the results of characterization, the supported Co nanoparticles (NPs) were composed of Co0 in the bulk, CoO film formed from air oxidation on the surface, and Co0 at Co NPs-TiO2 interfaces. This structure provided the possibility for a Z scheme photothermal catalytic system, which revealed a high activity for methanol formation in aqueous media under atmosphere pressure. It was proposed that the light excited electrons from the valence band (VB) of TiO2, and the excited electrons could enhance the Co0 catalytic activity under thermal conditions. The present approach will offer a new strategy to design Co based Z scheme catalysts and further improve the conversion efficiency from CO2 to fuels.

Direct hydroxylation of benzene to phenol with dioxygen is a green route for synthesis of phenol. The higher bonding energies of C–H in benzene and O–O in dioxygen make metal-free catalysis a challenge. A novel metal-free catalyst of quinone-cylcohexanone-formaldehyde polymer was rationally designed and prepared. The polymer was characterized with FT-IR, XRD, Raman, SEM, 13C NMR and XPS. Abundant oxygen functional groups of cyclic ketonic, quinone carbonyl and hydroquinone were found on the surface of polymer. The catalytic performances for hydroxylation of benzene to phenol with dioxygen over the metal-free catalyst were investigated and a phenol yielding of 11.4% was achieved. Moreover, the reaction mechanism was proposed.

In this work, we demonstrate that the amorphous silica-alumina composite (ASA) is an efficient solid acid for the steam reforming of dimethyl ether (SRD). Thus, a series of ASA with different Si/Al molar ratios was synthesized via the modified hydrolytic method by using Al(NO3)3·9H2O and/or NaAlO2 as Al precursor and tetraethoxysilane as Si precursor, respectively. Irrespective of the synthesis conditions, all of ASA composites were in an amorphous nature. However, both the acidity and the surface area were significantly affected by the synthesis conditions, the extent of which depends on the specific precursor and Si/Al molar ratios. The ASA physically mixed with a commercial Cu/ZnO/Al2O3 was investigated as a bifunctional catalyst for SRD under the conditions of P=0.1 MPa and gas hourly space velocity of 4000 h−1. Results indicate that both the conversion of dimethyl ether (DME) and the hydrogen yield were strongly dependent on the acidic property of ASA and the ASA to Cu/ZnO/Al2O3 ratios. Following the two-step consecutive mechanism of SRD, the catalytic results were well explained based on the acidic property of ASA, and the synergetic effect between the two catalytic functions was found to play a crucial role in determining the activity and stability of the bifunctional catalyst. Moreover, the DME hydrolysis was revealed to be the rate-limiting step for SRD reactions in the case of ASA as an acidic catalyst. By optimizing the synthesis conditions of ASA and the composition of the bifunctional catalyst, greater than 99% of DME conversion and hydrogen yield was achieved, and was kept for a time on stream of 66 h without an observable decrease. Thus, ASA is a very efficient solid acid for SRD.

Hyperbranched polymers have attracted increasing interests due to their unique structure-related advantages and have been utilized as drug carriers for controlled delivery. However, it is still challenging to prepare multi stimuli-responsive hyperbranched polymers to sense and response the complex yet delicate changes in physiological environment. Herein, we propose a triple-stimuli backbone-breakable hyperbranched polymer (HBP(OEG-IB)), which is prepared via the convenient iminoboronate multi-component reaction of α,ω-di(1,2-diol)s oligo(ethylene glycol), tris(3-aminopropyl)amine and 2-formylphenylboronic acid. Upon the stimulation of CO2, lactic acid and glutathione, micelles formed by HBP(OEG-IB) could be disrupted via the dissociation of iminoboronate ester bond to subsequent release incorporated camptothecin (CPT). Cell experiments show that the HBP(OEG-IB) is non-toxic but can enhance the therapeutic effect of CPT thanks to the effect of the protonated tertiary amino groups. The demonstration made in this work can enrich the design of responsive HBPs and can be readily applied to other systems with tunable responsive properties and functions.

The solid acid in metal-acid bifunctional catalysts for Fischer-Tropsch (FT) synthesis plays a crucial role for one-step selective synthesis of liquid fuels such as gasoline or diesel. In this work, the amorphous silica-alumina (ASA) synthesized by a one-step flame spray pyrolysis method (FSP) was demonstrated for the first time as an efficient solid acid for regulating the product distribution of FT synthesis. The 3 wt.% Ru impregnated ASA with different Al/(Al+Si) ratios was comparatively investigated for FT synthesis under typical conditions. The materials were characterized by XRD, STEM, H2-TPR, NH3-TPD, and N2 adsorption/desorption at low temperatures. In comparison with the ASA synthesized by the traditional sol-gel method, the ASA prepared by the FSP method showed clearly increased acidity. As a result, the selectivity of C13+ hydrocarbons was decreased while the selectivity of C5-12 hydrocarbons was increased, the extent of which is clearly dependent on the Al/(Al+Si) ratio of ASA. Moreover, both the carbon-chain length and the composition of olefins, normal and branched alkanes of FT products were easily regulated in a certain extent by simply changing the Al/(Al+Si) ratio of ASA. Thus, the enhanced and easily regulated acidity, rich porous structure, and available large-scale production of the ASA originated from FSP method make it an important solid acid for selective synthesis of liquid fuels via FT route.

In the present study, an overall decomposition mechanism of ammonium dinitramide (ADN) in the gas phase via density functional theory (DFT) calculations was studied. Thermogravimetry-Fourier transform infrared (TG-FTIR) and thermogravimetry-mass spectrometer (TG-MS) techniques were used to verify the calculation results. In the thermal decomposition of gaseous ADN (ADN(g)), ADN(g) first decomposed into dinitraminic acid (HDN) and NH3, followed by HDN decomposition into other products with small molecules. HDN is found to isomerize into five isomers (HDN-1–5) in the gas phase. For the initial decomposition of HDN, the favorable decomposition pathway of HDN-4 (a structure of HON(O)NNO2) is more likely to form HNO3 and N2O with a huge release of energy (approximately 45 kcal mol−1). Moreover, product HNO3 and NH3 can first combine to form NH4NO3. Both calculated and experimental results indicate that the product N2O is first formed in the thermal decomposition of ADN(g). Moreover, the formation mechanism and kinetics of other products (NH3, H2O, NO, N2O, NO2, HONO, HNO3, etc.) were also studied and proposed in the thermal decomposition of gaseous ADN. Overall, the systematic mechanistic investigations have provided new and detailed insights on the mechanism and kinetics of the thermal decomposition of gaseous ADN as well as informative factors to further improve the experimental performances, which can surely be beneficial to other energetic material syntheses.

The rapid consumption of conventional fossil fuels has caused a sharp decline in their reserves and led to climate change. Exploitation of renewable energy sources especially bio-fuels such as 2,5-dimethylfuran (DMF), methylfuran (MF), γ-valerolactone (GVL), etc. has both environmental and economic benefits. In the present work, diverse Co-based bimetallic catalysts were prepared and used for catalyzing hydrodeoxygenation (HDO) of biomass-derived oxygenates. Co5Zn1Ox, obtained by the incorporation of Zn species into the Co metal catalyst especially with a Co/Zn molar ratio of 5, could enhance the catalytic performances obviously compared to the sole Co catalyst. For example, the DMF, MF, and GVL yields reached up to 94, 98, and 77% during the catalysis by Co5Zn1Ox, which were much greater than 74, 0, and 23% for the Co catalyst, respectively. The enhanced performances of Co5Zn1Ox stem from the strong interaction between the Co and Zn species. Specifically, the presence of ZnO could stabilize Co2+ species, by offering electrons to Co species and creating oxygen vacancies, resulting in Co5Zn1Ox showing the highest adsorption amounts of furfural and furfuryl alcohol compared to Co1Zn1Ox and Co7Zn1Ox catalysts. Moreover, the catalyst showed good universality and reusability, and the HDO of 5-HMF to DMF proceeded in a true heterogeneous manner. The present work is believed to extend the application of bimetallic catalysts to the synthesis of bio-fuels and utilization of biomass materials.

Supported vanadium oxides are widely used as active catalysts for a number of oxidation and oxidative dehydrogenation reactions, and the understanding the structure-function relationship is of great importance for developing more efficient vanadium oxide catalysts. In this work, atomic layer deposition (ALD) was utilized to disperse sub-monolayer VOx over a commercial γ-Al2O3 support. Characterization results indicate that highly dispersed VOx species with different structures were obtained by simply changing the number of ALD cycles. The vanadium oxides synthesized by performing 1 cycle of ALD were exclusively isolated monomeric VOx. With increasing the number of ALD cycles from 3 to 8, the polymeric VOx spices were formed, and the polymerization extent or domain size of VOx was increased. On the contrary, crystalline V2O5 besides polymeric VOx was found if the number of ALD cycles was extended to 12. Catalytic performances of ALD VOx/γ-Al2O3 were evaluated for the oxidative dehydrogenation of ethylbenzene with CO2 (CO2-ODEB), and the isolated monomeric VOx species were found to be more active and more stable than the polymeric VOx species and crystalline V2O5. By correlating the specific activity and the structural characteristics of ALD VOx/γ-Al2O3 catalysts, the V O Al bonds were concluded as the key active sites for CO2-ODEB.

Ceria, zirconia, Ce0.9Zr0.1O2, Ce0.75Zr0.25O2, and Ce0.5Zr0.5O2 samples were synthesized via the two-step hydrothermal method by using Ce(NO3)3·6H2O and Zr(NO3)4·5H2O as the precursors, respectively. The oxides were applied as catalysts for the dehydrogenation of ethylbenzene by using carbon dioxide as a soft oxidant (CO2-ODEB) at 550 °C and 0.1 MPa. Reaction results indicate that ceria was the most active catalyst while the zirconia with a cubic structure was inactive for CO2-ODEB. In the cases of the oxides by inserting Zr into CeO2, the activity indexed by either the initial ethylbenzene (EB) conversion or the calculated turnover frequency (TOF) at a time on stream of 1 h was changed in the sequence of Ce0.9Zr0.1O2 >> Ce0.75Zr0.25O2 > Ce0.5Zr0.5O2 while the decreasing pattern of the stability was observed in the order of Ce0.5Zr0.5O2 ≈ Ce0.75Zr0.25O2 >> Ce0.9Zr0.1O2. As revealed from the characterization results of XRD and Raman, the pure cubic solid solution of Ce1-xZrxO2 without any phase separations was obtained irrespective of the compositions. By correlating the characterization results, the activity of Ce1-xZrxO2 for CO2-ODEB was determined by the amount of the Ce3+ oxidized by CO2 and the rate of Ce3+/Ce4+ redox cycles. Moreover, both the coking rate and the promoting effect of the deposited coke on CO2-ODEB were responsible for the stability of Ce1-xZrxO2.

The ordered mesoporous V2O5 (9 wt %)–Ce1–xZrxO2 (7 wt %)–Al2O3 (VCA-x, x = 0, 0.5, and 1) was successfully synthesized by combining the hydrothermal and the modified evaporation-induced self-assemb...

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