Publications by authors named "Zhong-wen Liu"

Sintering significantly contributes to the deactivation of supported metal catalysts under reaction conditions, influenced by various factors, including temperature, atmosphere, and metal-support interactions. The sintering mechanism under the reaction conditions remains complex and ambiguous. This study delves into the sintering behavior of platinum on CeO under CO oxidation conditions, mainly employing transmission electron microscopy to elucidate the effects of different gas components on the sintering mechanism at elevated temperatures.

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The surface frustrated Lewis pairs (SFLPs) open up new opportunities for substituting noble metals in the activation and conversion of stable molecules. However, the applications of SFLPs on a larger scale are impeded by the complex construction process, low surface density, and sensitivity to the reaction environment. Herein, wurtzite-structured crystals such as GaN, ZnO, and AlP are found for developing natural, dense, and stable SFLPs.

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Magnetic hydrogel actuators are developed by incorporating magnetic fillers into the hydrogel matrix. Regulating the distribution of these fillers is key to the exhibited functionalities but is still challenging. Here a facile way to spatially synthesize ferrosoferric oxide (FeO) microparticles in situ in a thermal-responsive hydrogel is reported.

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Redispersion is an effective method for regeneration of sintered metal-supported catalysts. However, the ambiguous mechanistic understanding hinders the delicate controlling of active metals at the atomic level. Herein, the redispersion mechanism of atomically dispersed Pt on CeO is revealed and manipulated by techniques combining well-designed model catalysts.

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The shapes of rubbers and elastomers are challenging to alter, and current methods relying on permanent plasticity and dynamic cross-linking strategies are usually laborious and can inevitably compromise the network elasticity. Here, we report a photoresponsive elastic composite that can be programmed into 3D shapes by first UV light irradiation and then stretching. The composite comprises ethylene propylene rubber as the elastic substrate and photoliquefiable azobenzene small molecules as the responsive filler.

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Knowing the structure of catalytically active species/phases and providing methods for their purposeful generation are two prerequisites for the design of catalysts with desired performance. Herein, we introduce a simple method for precise preparation of supported/bulk catalysts. It utilizes the ability of metal oxides to dissolve and to simultaneously precipitate during their treatment in an aqueous ammonia solution.

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Polymeric materials that can actuate under the stimulation of environmental signals have attracted considerable attention in fields including artificial muscles, soft robotics, implantable devices, etc. To date, the improvement of shape-changing flexibility is mainly limited by their unchangeable shapes and structural and compositional distributions. In this work, we report a one-step treatment process to convert 2D poly(ethylene oxide)/sodium alginate/tannic acid thin films into 3D-shaped moisture- and NIR light-responsive actuators.

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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. Herein, it is reported 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.

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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--2-(dimethylamino)ethyl methacrylate)/alginate hydrogels with programmable external shapes and internal actuating trajectories.

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The oxidative dehydrogenation of propane with CO (CO-ODP) has been extensively investigated as a promising green technology for the efficient production of propylene, but the lack of a high-performance catalyst is still one of the main challenges for its industrial application. In this work, an efficient catalyst for CO-ODP was developed by adding CeO to PtSn/SiO as a promoter via the simple impregnation method. Reaction results indicate that the addition of CeO significantly improved the catalytic activity and propylene selectivity of the PtSn/SiO catalyst, and the highest space-time yield of 1.

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The minimized diffusion limitation and completely exposed strong acid sites of the ultrathin zeolites make it an industrially important catalyst especially for converting bulky molecules. However, the structure-controlled and large-scale synthesis of the material is still a challenge. In this work, the direct synthesis of the single-layer MWW zeolite was demonstrated by using hexamethyleneimine and amphiphilic organosilane as structure-directing agents.

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Bladder cancer is a common malignant tumor with a high recurrence rate and mortality, while the detailed mechanisms for bladder cancer progression and metastasis are unknown. Recently, long non-coding RNAs (lncRNAs) have been reported to be involved in the development of cancers. In this study, we aim to investigate the role of lncRNA LINC00355 in bladder cancer progression and metastasis.

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The size effects of metal catalysts have been widely investigated to optimize their catalytic activity and selectivity. However, the size-controllable synthesis of uniform supported metal nanoparticles without surfactants and/or additives remains a great challenge. Herein, we developed a green, surfactant-free, and universal strategy to tailor the sizes of uniform Pd nanoparticles on metal oxides by an electroless chemical deposition method defect engineering of supports.

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Article Synopsis
  • The study explores the use of gallium nitride (GaN) as a high-performance catalyst for the selective hydrogenation of carbon monoxide (CO) to dimethyl ether (DME), achieving around 80% CO-free selectivity.
  • GaN shows significantly higher activity for CO hydrogenation compared to traditional methods, enabling a different pathway for producing DME without relying on methanol intermediates.
  • Experimental results and theoretical calculations reveal that DME forms primarily through methyl and formate intermediates, which highlights an innovative approach in catalyst technology for transforming CO into valuable chemicals.
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Article Synopsis
  • Researchers developed a new method using rhodium(III) as a catalyst to create indane-fused pyrrolidine-2,5-diones from aromatic aldehydes and maleimides through a tandem [3+2] cyclization process.
  • The method allows for different product outcomes by simply changing additives and adjusting the reaction time.
  • This efficient process utilizes the activation of C-H bonds without needing nitrogen-based directing groups, works well in air, and shows exclusive stereoselectivity.
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Metallic platinum nanocatalysts play a key role in the liquid-phase selective hydrogenation of substrates with more than one unsaturated bond. However, the commonly applied explanation for the effects of different electronic and geometric properties of catalysts on reactions remains of a heuristic nature due to the difficulties involved in preparing catalysts with precise structure. In this work, we have directly loaded pre-synthesized metallic platinum nanoparticles onto well-structured ZnO nanorods and then subjected them to thermal treatment in a reductive atmosphere for different temperatures.

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The aromatic aldehyde as a traceless directing group for the regionselective C-H alkylation catalyzed by rhodium(III) under aerobic atmospheric conditions has been developed. The process involves an aldehyde assisted direct addition of C-H bond to unsaturated electrophiles of acrylates or acrylic acids, and the subsequent decarbonylation. A trace amount of water is found to favor the reaction.

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High pressure in situ Fourier transfer infrared/near infrared technology (HP FTIR/NIR) along with theoretical calculation of density functional theory (DFT) method was employed. The solvation behaviors and the free radical homopolymerization of methyl methacrylate (MMA), methacrylate acid (MAA), trifluoromethyl methacrylate (MTFMA) and trifluoromethyl methacrylate acid (TFMAA) in scCO were systematically investigated. Interestingly, the previously proposed mechanism of intermolecular-interaction dynamically-induced solvation effect (IDISE) of monomer in scCO is expected to be well verified/corroborated in view that the predicted solubility order of the monomers in scCO via DFT calculation is ideally consistent with that observed via HP FTIR/NIR.

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The one-step strategy for the facile syntheses of structurally diverse 1-indanones in moderate to good isolated yields was developed via a ruthenium-catalyzed tandem coupling and cyclization of simple aromatic acids with α,β-unsaturated ketones. The tandem cyclization involves one-pot sequential reactions of C-H activation, conjugate addition, Dieckmann condensation, Michael addition, intramolecular Aldol reaction, or hydrolysis. Switchable access to spiroindanones and 2-substituted 1-indanones could be achieved by manganese additive and HO.

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Objectives: To set up ELISA for detection of atrazine with high precision.

Methods: The reaction condition of indirect-ELISA was optimized, including atrazine-ovalbumin(AT-OVA) concentration and primary antibody concentration, organic solvent, goat anti-rat immunoglobin G-horseradish peroxidase(IgG-HRP) concentration. The actual samples were detected by the ELISA method established in our laboratory.

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The hydrolysis mechanism and the kinetics of using 2-dinitromethylene-5,5-dinitropyrimidine-4,6-dione (NMP) to prepare the representative insensitive energetic material 1,1-diamino-2,2-dinitroethylene (FOX-7) in a nitric-sulfuric acid system are systematically investigated a density functional theory (DFT) method. The impact of the co-existing acidic group of HSO as well as the solvent effects of the mixed acids on the hydrolysis of NMP are elucidated and discerned, and the proposed catalysis and promotion of the hydrolysis of NMP with HSO are verified. The HSO -catalyzed hydrolysis pathway is more favorable than the direct pathway as well as the HO-catalyzed hydrolysis, indicating that HSO may be a promising catalyst for the preparation of FOX-7 in a mixed acid system.

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A novel, high-efficiency and high-selectivity construction of β-trifluoromethyl enol ether via base-induced/promoted C-O coupling of trifluoromethylated vinyl chloride and phenols is presented with a broad substrate scope. The reaction mechanism, especially the significantly high selectivity, was excavated and understood via DFT calculation and is well supported by the experimental observation.

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A palladium-catalyzed direct C-arylation reaction of readily available cage carboranyllithium reagents with aryl halides has been developed for the first time. This method is applicable to a wide range of aryl halide substrates including aryl iodides, aryl bromides, and heteroaromatic halides.

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A catalyst-free multicomponent CDC reaction is rarely reported, especially for the intermolecular tandem CDC cyclization, which represents an important strategy for constructing cyclic compounds. Herein, a three-component tandem CDC cyclization by a Pummerer-type rearrangement to afford biologically relevant isoindolinones from aromatic acids, amides, and DMSO, is described. This intermolecular tandem reaction undergoes a C(sp(2) )-H/C(sp(3) )-H cross-dehydrogenative coupling, C-N bond formation, and intramolecular amidation.

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An interface microenvironment between nanocarbon and ionic liquids (ILs) is presented. By an entrapping effect, a few layers of ILs can be finely deposited on the surface of nanocarbon, endowing amazingly tailorable surface properties. The entrapped IL layer, which was believed to be unable to be charred under pyrolysis conditions alone, can be further carbonized to a functional carbon layer.

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