168 results about "Nanocomposite catalyst" patented technology

The invention discloses a nano-grade composition, a preparation method thereof, and an application thereof as an electrochemical catalyst. The nano-grade composition provided by the invention is basically composed of a melamine derivative, a carbon material, and transition metal or transition metal alloy nano-cluster. The carbon material comprises at least one selected from conductive carbon black, activated carbon, carbon nano-horn, N-doped carbon nano-horn, carbon nano-tube, graphene, graphite and carbon fiber material. The metal nano-cluster is at least one selected from Pt, Ru, Pd, Rh and Ir nano-clusters. The alloy nano-cluster is nano-cluster formed by more than two elements selected from Pt, Ru, Pd, Rh, Ir, Fe, Cu and Ni. The mass percentage content of the transition metal or alloy nano-cluster is 0.1-90%. The size of the transition metal or alloy nano-cluster is 0.5-10nm. As a fuel cell catalyst, the nano-grade composition provided by the invention has excellent electrocatalytic activity upon reactions such as oxygen reduction and methanol oxidation.

A method for preparing a carbon nano tube loaded cobalt-platinum alloy catalyst belongs to the fields of nano composite catalysts and fuel cells. The electrode catalyst of the conventional fuel cell has the problems of uneven grain size distribution of active components, high cost and the like. By using a carbon nano tube working electrode containing a cobalt-platinum based active precursor as a cathode, using a platinum electrode as an anode and using solid-phase electrolysis salt as electrolyte, the carbon nano tube loaded cobalt-platinum alloy catalyst is generated in situ through pulse electro-deposition. The method has the advantages that the method can effectively control the grain size, composition and load of Co-Pt alloy nano grains, has low cost and no pollution, and is suitable for large-scale production and the like.

The invention belongs to the field of catalyst preparation, and particularly relates to a complex nano-catalyst for preparing synthesis gas by reforming methane and carbon dioxide, and a preparation method thereof. The complex nano-catalyst comprises an active ingredient, an accessory ingredient and a complex carrier, wherein the active ingredient is composed of cobalt oxide and nickel oxide; the accessory ingredient is composed of one or more of potassium oxide, magnesium oxide or lanthanum oxide; the complex carrier is composed of two of nano aluminium oxide, nano zirconium oxide or nano silicon oxide. The preparation method comprises the following steps: preparing a mixed solution; preparing the complex nano-catalyst. The complex nano-catalyst is small in particle diameter of the complex carrier, has high surface energy and surface defects, increases catalyst active sites, activates carbon dioxide to generate active oxygen, assists carbon elimination, reduces the yield of carbon, slightly improves stability of the complex nano-catalyst, and prolongs the use period of the complex nano-catalyst; the preparation method is simple, scientific and reasonable.

The invention discloses an enzyme-GO-MOFs nano composite catalyst and a preparation method thereof. The preparation method comprises the following steps: (1) adding a modifier into an enzyme liquid so as to obtain a modified enzyme solution, wherein the modifier is an N-vinyl amide polymer or pluronic F-127; the N-vinyl amide polymer is one or a mixture of more of polyvinylpyrrolidone, poly N-vinyl caprolactam and poly N-ethylene formamide; (2) mixing GO and a metallic salt solution, performing ultrasonic treatment, further adding an organic ligand solution into the mixed solution so as to obtain a GO-MOFs composite material synthesized stock solution, and performing ultrasonic treatment for another time; (3) adding a modified enzyme solution into the GO-MOFs composite material synthesized stock solution, and performing ultrasonic treatment so as to obtain a reaction liquid; (4) centrifuging the reaction liquid, collecting precipitate, washing the precipitate, and performing vacuum drying, thereby obtaining the enzyme-GO-MOFs nano composite catalyst. The preparation method disclosed by the invention is simple and feasible, and the nano composite material catalyst is gentle in synthesis condition and high in protein immobilization rate.

The present invention belongs to the technical field of electrochemistry, specifically relates to a graphene-platinum (RGO-Pt) nano-composite catalyst for a lithium air battery, and a preparation method thereof. The nano-composite catalyst material is prepared by a liquid phase pulsed laser ablation technology (LP-PLA). With adopting the membrane electrode prepared by the composite catalyst for the lithium air battery anode material, the lithium air battery has good charge-discharge cycle reversibility, the charge-discharge over voltage is significantly decreased, and the reversible specific capacity under the current density of 100 mA/g is more than 4000 mAh/g. The membrane anode material based on the graphene-platinum (RGO-Pt) nano-composite catalyst has characteristics of good chemical stability, high specific capacity, excellent cycle performance and simple preparation method, and is applicable for the lithium air battery.

The invention discloses a magnetic nano composite catalyst, in particular to a preparation method of a ferrocobalt oxide/graphene magnetic nano composite catalyst and an application of the magnetic nano composite catalyst in degrading organic wastewater. The catalyst acts on sulfate radicals with a strong oxidizing property generated by peroxysulfate and therefore efficiently removes organic matters from the wastewater. The catalyst serving as a solid phase catalyst has larger specific surface area, higher catalytic activity and a lower ion release rate, so that the catalyst can continuously and efficiently activate the sulfate radicals generated by peroxysulfate and effectively reduce cobalt ion leakage. The preparation method of the catalyst is simple; the catalyst has high catalytical performance, does not cause secondary pollution and is an environment-friendly material; since the catalyst is magnetic and can be recycled after reaction, the treatment cost of the organic wastewater is lowered; wide application prospects are provided for the treatment of the degradation-resistant organic wastewater.

The invention provides a comprehensive treatment pneumatic caisson method for indoor environment pollution, and is used for solving the problem that concentrations of indoor formaldehyde, indoor benzene, indoor ammonia and indoor TVOC (total volatile organic compound) exceed the national standard. The comprehensive treatment pneumatic caisson method comprises the step of: applying the following six treatment solutions in an occasion that the concentrations of the indoor formaldehyde, the indoor benzene, the indoor ammonia and the indoor TVOC (total volatile organic compound) exceed the national standard: a nanocomposite catalyst solution, 1%-50% of acetum, a formaldehyde treatment solution containing active amido, a VOC (volatile organic compound) stabilizing solution, a negative oxygen ion generator and a deodorant. According to the application of the comprehensive treatment pneumatic caisson method for the indoor environment pollution, provided by the invention, the concentrations of pollutants after treatment are obviously reduced; and various effects are obtained for reducing the concentrations of the pollutants including the indoor formaldehyde, the indoor benzene, the indoor TVOC, the indoor ammonia and the like caused by furniture, floor, doors and window, carpets, wallpaper, fabrics, paint, coatings, dyes, building materials and the like.

The invention relates to a nano-composite air electrode catalyst for a zinc-air battery and a preparation method of the nano-composite catalyst, belonging to the technical field of zinc-air batteries. The nano-composite catalyst is composed of manganese dioxide, nano-silver, a carbon nano tube and a carbon material in the mass ratio of (0-0.5) to (0-0.5) to 1 to (1.75-2.75), wherein the mass of manganese dioxide and the mass of nano-silver cannot be zero at the same time. Due to the addition of nanometer materials such as nano-silver and the carbon nano tube, the wettability of the nano-composite catalyst is improved, and the reduction reaction of oxygen in a three-phase boundary formed by electrolyte, catalyst material and oxygen is facilitated; meanwhile, the composite catalyst formed by manganese dioxide and nano-silver has oxygen reduction effect higher than that of a single catalyst. The nano-composite catalyst adopts the preparation technology comprising the steps of pretreatment, granulation, ultrasonic dispersion and ball-milling treatment, the operation is simple and efficient, and the application prospect is good.

A composition for treating dye wastewater and method of synthesizing said composition, is disclosed. The composition is a catalyst composition used for ultrasound irradiation process. The composition comprises a copper sulfide and cobalt ferrite (Cu₂S/CoFe₂O₄) nanocomposite material, and hydrogen peroxide (H₂O₂). Further, the present invention also discloses a method for treating dye wastewater using said nanocomposite catalyst composition. The composition according to the present invention, provides a novel, eco-friendly and economical method for the complete degradation of the organic dye pollutants from the industrial wastewater. Further, the sonocatalyst has enough stability, as its structure and degradation ability does not change even after multiple use. Further, the sonocatalyst could be easily separated and reused from a waste water, without any need for complex separation process.

The invention provides a nano-composite catalyst and a preparation method thereof, belongs to the technical field of catalyzing, and solves the problem that the conventional load nano-composite oxide catalyst is low in nano-composite degree, and poor in catalyzing performance. The nano-composite catalyst is obtained by the flowing steps based on the condition that a surface-active agent is not used: firstly, reducing composite oxide crystal lattices or first metal ions mixed in the crystal lattices so as to obtain nano-metal granules containing first metal; and then introducing second metal into the surface of the first metal by Galvanic substitution reaction so as to obtain the nano-composite catalyst. Compared with the conventional catalyst, the nano-composite catalyst has more efficient catalyzing performance when being used for catalytic reaction of VOC (volatile organic compound) removal, automobile tail gas purification, formaldehyde removal, methane combustion, hydrogenation, hydrogenolysis, ammonia synthesis, ammonia decomposition, hydrocarbon synthesis, hydroformylation and the like.

Provided are a three-dimensional carbon nanotube nano composite catalyst, and a preparation method and application thereof, which belong to the technical field of nano-material preparation. The nano composite catalyst contains carbon nanotube sponge and cadmium sulfide nano particles. The preparation method includes the step that the carbon nanotube sponge is dipped in an organic solution of the cadmium sulfide nano particles, so that the cadmium sulfide nano particles adhere on a surface and in apertures of the carbon nanotube sponge to form a three-dimensional carbon nanotube nano compositecatalyst. The invention also provides application of the catalyst to adsorption-photocatalysis degradation of dye molecules in water. On the one hand, the carbon nanotube sponge has large specific surface area, good adsorption property, and is easily operated and processed; on the other hand, the cadmium sulfide nano particles have high photocatalytic activity, and can catalyze degradation of dyemolecules in water under visible light. Therefore, the nano composite catalyst obtained in the invention has advantages of large adsorption quantity, high degradation efficiency, easy operation and processing, and capability of simultaneously degrading a plurality of pollutants in water, etc.

The invention discloses a wire mesh loaded 'metal-metal oxide' nano composite catalyst, and an application thereof in catalytic alcoholic preparation of aldehyde ketone. The catalyst is prepared by using a wire mesh subjected to surface pretreatment to load a 'metal-metal oxide' nano composite. The wire mesh loaded 'metal-metal oxide' nano composite catalyst is simple and convenient in preparation, easy to amplify, low in preparation cost, good in heat conductivity, high in low-temperature activity, high in selectivity and good in stability; and moreover, the wire mesh loaded 'metal-metal oxide' nano composite catalyst is applied to a reaction for preparing aldehyde ketone by catalyzing selective oxidation of alcohol, so that the efficiency is high, the reaction is environment-friendly, and the production cost is low.

The present invention discloses a preparation method of a charcoal-supported palladium-silver nanometer composite catalyst for direct methanol fuel cells. The method comprises: in the presence of polyvinylpyrrolidone, adding a NaOH aqueous solution to adjust the pH value of the reaction system, and using NaBH4 as a reducing agent to prepare the charcoal-supported palladium-silver nanometer composite catalyst. According to the present invention, the morphology of the palladium-silver nanoparticles in the charcoal-supported palladium-silver nanometer composite catalyst is characterized through TEM, and the methanol electrochemical oxidation activity of the charcoal-supported palladium-silver nanometer composite catalyst is evaluated by using the cyclic voltammetry method.

The invention provides a preparation method of a transition metal hexacyanoferrate/titanium dioxide nanocomposite catalyst. According to the preparation method, by taking transition metal chloride or transition metal nitrate, potassium ferrocyanide and titanium dioxide as raw materials, through an in-situ chemical solution method, in-situ growth of transition metal hexacyanoferrate (MHCF) is carried out on the surfaces of titanium dioxide nanoparticles to obtain the MHCF/TiO2 nanocomposite catalyst. The invention also provides a method for degradation of organic pollutants by light-fenton concerted reaction of the MHCF/TiO2 nanocomposite catalyst. According to the method, in dark reaction in the absence of light, the organic pollutants can be degraded by the MHCF in the form of fenton reaction, while under ultraviolet irradiation, the titanium dioxide (photocatalyst) can generate electron-hole pairs, electrons can accelerate reduction of ferric iron oxidized by H2O2 in the MHCF, meanwhile, the MHCF receiving the electrons of the titanium dioxide can also inhibit compounding of photoelectron holes, and then accelerate the generating efficiency of hydroxyl radicals during fenton reaction and a photocatalytic process, and the synergistic effect of the MHCF and the electrons has very high degradation efficiency for various different organic pollutants.

The nanometer composite catalyst disclosed by the present invention is a compound which comprises nano-titanium, nano-silicon and a metal element selected from groups IA, IIA, IIIA, IVA, IIB, IIIB, IVB and VIII elements. A synthetic method provided by the present invention comprises the following steps: a) carrying out an esterification or a ester exchange reaction, then adding aromatic dibasic acids or aromatic dibasic ester and aliphatic diol to a reaction vessel according to a certain ratio, and simultaneous adding catalysts for the esterification; b) carrying out a pre polycondensation at a certain reaction temperature under a certain reaction pressure, followed by a polycondensation at a certain reaction temperature under a certain reaction pressure.