The present invention refers to catalysts that are selective for the reaction of ODH of propane to propene. Said catalysts are potassium salts of the dodecatungstophosphate ion partially substituted with vanadium and niobium, or mixed oxides of W, V, and Nb, with a tungsten bronze structure, obtained by thermal decomposition of polyoxometalate salts with a Keggin structure.

The invention discloses a visible light responsive tricobalt tetraoxide dodecahedron/carbon nitride nanosheet composite and an application thereof in exhaust gas treatment. The preparation method of the composite comprises the following steps: with urea as a precursor, carrying out twice calcination to obtain carbon nitride nanosheet; dispersing the carbon nitride nanosheet into methanol, sequentially adding cobalt nitrate hexahydrate and 2-methylimidazole, and carrying out a reaction to obtain a carbon nitride nanosheet composite; and calcining the carbon nitride nanosheet composite in an air atmosphere at a low temperature to obtain the tricobalt tetraoxide dodecahedron/carbon nitride nanosheet composite. The in-situ growth synthesis method can ensure that the tricobalt tetraoxide obtained by follow-up calcination is uniformly coated on the carbon nitride nanosheet to improve the catalytic performance; the low temperature calcination ensures that the carbon nitride can maintain its wrinkle state and chemical structure during the calcination process.

The instant invention provides processes for a chemo selective reduction of a nitro group within a compound in the presence of other groups which can also be reduced. This aspect of the present invention provides an ammonia borane (AB) initiated chemoselective reduction process of a nitro group contained within a compound in the presence of a copper (Cu) nanoparticle based catalyst. The invention is also directed to Copper (Cu) nanoparticle (NP) based catalysts, selected from Cu/WO.sub.x, Cu/SiO.sub.2, and Cu/C; wherein x represents an integer having a value of from about 2 to about 3.5, used in the chemo selective reduction of a nitro group contained within a compound in the presence of other groups which can also be reduced.

The present disclosure provides a lignite char supported nano-cobalt composite catalyst and a preparation method thereof. In the method, lignite is used as a raw material, and a lignite char supported high dispersion nano-cobalt composite catalyst is obtained by a modified impregnation method followed by a high temperature pyrolysis process. The composite catalyst prepared by the present disclosure has a hierarchical pore structure, a high specific surface area, and uniformly dispersing nano-sized cobalts on the lignite char with controllable particle size, so that the obtained catalyst has an excellent catalytic activity for low-temperature CO.sub.2 methanation; moreover, the preparation process is simple and feasible, the raw materials used are cheap and easily available. Therefore, the composite catalyst is very suitable for industrial production and application.

The present invention is related to a new metal powder catalytic system (catalyst), its production and its use in hydrogenation processes.

The present disclosure provides a preparation method of an efficient and stable catalytic membrane based on a multi-scale hollow molecular sieve fiber, and belongs to the technical field of molecular sieve preparation. The preparation method includes the following steps: mixing a silicon source, an aluminum source, water, and an organic template, and stirring; heating, and adding deionized water; conducting a reaction by hydrothermal synthesis; conducting centrifugation on an obtained suspension, loading by mixing an obtained powder free of a mother liquor with an iron source, and washing and drying; dissolving a treated powder in anhydrous ethanol and conducting an ultrasonic treatment; adding a surfactant to an obtained dispersion, stirring, and conducting the ultrasonic treatment; and conducting coaxial electrospinning and calcination in sequence to obtain the membrane based on a hollow molecular sieve fiber.

A nanocomposite photocatalyst is provided. The nanocomposite photocatalyst contains carbon nitride particles, a polymer composite comprising a conducting polymer and a carbon nanomaterial, the polymer composite being disposed on the carbon nitride particles, and noble metal nanoparticles disposed on both the polymer composite and the carbon nitride particles. Also provided is a method of forming the nanocomposite photocatalyst and a method of photodegrading an organic pollutant in water using the nanocomposite photocatalyst and visible light irradiation.

The present invention belongs to the field of sewage treatment, and relates to a method for preparing a modified natural wood material and an application thereof in sewage treatment. The method for preparing the modified natural wood material includes the following steps: S1. placing wood into a lignin removal solution, after a heating reaction, washing, impregnating, and lyophilizing the wood to obtain removed lignin wood; S2. blending TiO.sub.2 with NaBH.sub.4, performing low-heat reduction treatment, and then washing and drying to obtain reduced black titanium; S3. dispersing the reduced black titanium ultrasonically in a solvent, then coating dropwise on the removed lignin wood, and drying to obtain a modified natural wood material. The modified natural wood material prepared by the present invention has high disinfection and sterilization performance, and has the ability to remove bio-risk components.

The present disclosure is related to a method for preparing a gaseous- or liquid-nitridation treated core-shell catalyst and, more specifically, to a method for preparing a gaseous- or liquid-nitridation treated core-shell catalyst comprising steps of: nitridation-treating a transition metal precursor core and noble metal precursor shell particles in the presence of a gaseous nitrogen source; or forming a transition metal precursor core and noble metal precursor shell particles, by means of a liquid nitrogen source, and at the same time allowing the nitrogen source to bond with the transition metal precursor and thus allowing nitridation treatment. Therefore, the present disclosure allows a high nitrogen content in the core and thus enables a prepared catalyst to have excellent durability, a small average particle size and high degree of dispersion and uniformity, and thus to be suitable for the fuel cell field.

A general and controlled method for synthesizing amorphous Pd-based nanoparticles is provided. The provided method comprises: dissolving a Pd precursor in a first solvent to form a first solution; mixing the first solution with a second solvent to form a first mixture; adding surfactant into the first mixture to form a second mixture; heating the second mixture to render a second solution; adding other metal precursor into the second solution to form a third mixture; heating the third mixture to render a third solution; naturally cooling down the third solution; adding ethanol to the third solution to form a fourth solution; and collecting the amorphous Pd-based nanoparticles from the fourth solution. The provided method allows tuning of the phase of Pd-based nanoparticles to obtain amorphous Pd-based nanocatalysts to efficiently switch the ring-opening route of epoxides for the synthesis of distinct targeted chemicals and modulating of the catalytic performance thereof in electrochemical hydrogen emission reactions.