923results about How to "Prevent sintering" patented technology

The invention discloses a catalyst for the complete methanation of synthesis gas from coal and a preparation method thereof. The catalyst is prepared by using NiO as an active component, one or two of rare earth metal oxides La2O3, CeO2 and Sm2O3 as a first assistant, one of alkali oxides CaO, BaO and SrO as a second assistant, and magnesium aluminate spinel formed by mixing Al2O3 with MgO as a carrier, and the obtained catalyst contains the ingredients in percent by mass as below: 20% to 70% of NiO, 15% to 50% of Al2O3, 6% to 30% of MgO, 5% to 20% of the rare earth metal oxide-type first assistant, 1% to 8% of the alkali oxide-type second assistant and 1% to 3% of graphite; the catalyst provided by the invention has the advantages of high catalytic activity, high mechanical strength, good thermal stability, strong carbon deposition resistance, strong resistance to toxicants in feed gas, excellent low temperature activity and low cost.

A perovskite thin-film photovoltaic cell, including: a transparent conductive substrate, an electron transport layer, a perovskite absorption layer, a hole transport layer, and a metal electrode in that order. The electron transport layer is a tin dioxide thin-film. The invention also provides a method for preparing the perovskite thin-film photovoltaic cell. The method includes: (1) cleaning the transparent conductive substrate and then drying the transparent conductive substrate using nitrogen gas; (2) coating a SnO₂ electron transport layer on the transparent conductive substrate; (3) coating a CH₃NH₃PbI_3-xCl_x or CH₃NH₃PbI₃ absorber on the electron transport layer; and (4) spin-coating a solution including hole transport material on the perovskite absorber layer and then evaporating the metal electrode.

The invention discloses a preparation method of a low-load-capacity and high-activity load type ruthenium catalyst using titanium dioxide as a carrier. According to the invention, the titanium dioxide is used as the carrier, an ageing solution is illuminated by using ultraviolet rays in a precipitation and deposition ageing process, thus interaction of a ruthenium precursor and the titanium dioxide is enhanced, the dispersion degree of the precursor is improved, and further the high-dispersion titanium dioxide loaded ruthenium catalyst is obtained. The preparation method has the advantages of simple equipment and process, high yield, and convenience for industrialized production; and the prepared ruthenium catalyst has the advantages of small ruthenium granularity and good reproducibility. The ruthenium catalyst is applied to a process for synthesizing methane by carbon dioxide through hydrogenation, and has high reactant transformation rate, high selectivity and good stability.

The present invention provides a metal oxide particle for a catalyst support comprising multiple species of metal oxides and capable of satisfactorily exerting the properties of the respective metal oxides, and also provide a production process therefor and an exhaust gas purifying catalyst obtained from this metal oxide particle. A metal oxide particle of the present invention comprises a core part 1 relatively rich in a first metal oxide and a surface layer 2 relatively rich in a second metal oxide, the core part and the surface layer each comprising a plurality of primary particles (1a, 2a), and the primary particle diameter of the second metal oxide being smaller than the primary particle diameter of the first metal oxide.

The invention discloses a method for low-temperature oxidative degradation of organic gas. The method comprises the steps that a nanotube limited-range active component catalyst is used as a catalyst, a reaction is carried out under the conditions that the temperature is 45-220 DEG C and the airspeed is 100-100000h<-1> for 0.5-1500h for a catalytic oxidation degradation reaction of organic gas, and the organic gas is oxidized into degradation reaction and water. According to the method, by means of the nanotube open-framework structure and micronanospace, the active component of the catalyst for treating organic gas is planted into the nanotube open-framework structure to prepare the nanotube limited-range active component catalyst with high activity and stability, the limited-range catalyst is used for oxidative degradation of organic gas and can rapidly oxidize the organic gas at a low temperature into carbon dioxide and water, the organic gas removal rate reaches up to 95% or more, the catalyst is high in activity and long in service life, and the problems that reaction temperature is high, catalyst activity and stability are low and the catalyst active component service life is short in the prior art are solved.

A method of producing an elemental material or an alloy thereof from a halide or mixtures of halides is provided. The halide or mixtures thereof are contacted with a reducing gas in the presence of reductant material, preferably in sufficient quantity to convert the halide to the elemental material or alloy and to maintain the temperature of the reactants at a temperature lower than the boiling point of the reductant material at atmospheric pressure or the sintering temperature of the produced elemental material or alloy.

A bearing structure is provided with a turbine side bearing metal (30a) and a compressor side bearing metal (30b) in which an outer peripheral surface is fitted to a bearing hole (16a) of a bearing housing (16) with a gap, and an inner peripheral surface rotatably supports a turbine shaft (12), and a bearing locking member (32) holding the turbine side bearing metal and the compressor side bearing metal so as to be movable in a radial direction of the turbine shaft and inhibit a movement in an axial direction and a rotating direction. The inner peripheral surface and/or the outer peripheral surface of the bearing metal (30b) (or 30b) is structured as a non-complete round bearing.

This invention provides a method for preparing spherical Al2O3 with high hydrothermal stability. Based on the mechanisms of Al2O3 sintering and phase change, the method introduces phosphate ions, which can react with OH groups on the pore walls to reduce the quantity of OH groups and change the surface acidity of Al2O3. The method can prevent the sintering and phase change of Al2O3 pore channels, thus can improve the hydrothermal stability of spherical Al2O3 carrier. The hydrothermal stability of modified spherical Al2O3 is much higher than that of unmodified spherical Al2O3. The specific surface area of modified spherical Al2O3 is 190-200 m2/g, the pore volume is 0.85-1.25 mL/g, the particle diameters are 0.5-5 mm, the packing density is 0.3-0.55 g/cm3, and the weight content of P2O5 is 0.5-5%. The spherical Al2O3 can be used as catalyst or catalyst carrier for petrochemicals and fine chemicals.

A catalyst composition is provided for use on a diesel particulate filter which facilitates the oxidation of soot from diesel engine exhaust and which generates low NO₂ emissions during regeneration of the filter. The catalyst composition includes a catalytic metal comprising a platinum group metal selected from Pt, Pd, Pt—Pd, or combinations thereof, an active metal oxide component containing Cu and La; and an oxide component selected from oxides of Co, Fe, or combinations thereof. The catalyst composition includes a support selected from alumina, silica, zirconia, or combinations thereof. The catalyst composition may be provided on a diesel particulate filter by impregnating the filter with an alumina, silica or zirconia sol solution modified with glycerol and/or saccharose, impregnating the filter with a stabilizing solution, and impregnating the filter with a solution containing the catalyst metal precursor(s), the active metal oxide precursor(s) and the Co or Fe oxide(s). The resulting catalyst coated diesel particulate filter provides effective soot oxidation, exhibits good thermal stability, has a high BET surface area, exhibits minimal backpressure, and produces low NO₂ emissions during filter regeneration.

A method for producing hydrogen by contacting water, steam or gas containing steam with iron or iron oxide, wherein the iron or iron oxide is added with at least one metal of Rh, Ir, Ru, Pd, Pt and Os and at least one metal of Ti, Zr, V, Nb, Cr, Mo, Al, Ga, Mg, Sc, Ni and Cu. The method provides a medium for producing hydrogen which is capable of producing hydrogen at relatively low temperature and at a great generation rate, is free from the decrease of activity, and is resistance to repeated oxidation and reduction, which leads to the decomposition of water and production of hydrogen with good efficiency.

The invention provides a catalyst for tail gas purification and a preparation method of the catalyst for tail gas purification. The catalyst for tail gas purification comprises an alumina supporter, cerium dioxide borne on alumina and a precious metal active component borne on the surface of the cerium dioxide. The alumina supporter and the cerium dioxide are prepared according to the sediment hydrothermal method. The precious metal active component is borne according to the hydrothermal in-situ reduction sediment method. According to the catalyst for tail gas purification, the interaction between the cerium dioxide and a precious metal species is strong, the cerium dioxide supporter can generate more oxygen vacancies, oxygen molecules are activated and converted into a reactive oxygen species, and therefore the activity of catalytic oxidation is improved. Interspersion and mutual contact are conducted between the alumina and the cerium dioxide, the mutual insulation function is achieved, sintering with the single cerium oxide serving as a supporter can be avoided, and the thermal stability of the alumina at a high temperature is remarkably improved.

The invention discloses a metal@BN core-shell structure nanometer catalyst for a synthesis gas methanation reaction, and a preparation method thereof. According to the present invention, the composition of the catalyst is 5-30wt.%Mx@(BN)y/SiO2, wherein metal M nanoparticles are loaded on a SiO2 support, the loading mass percentage is 5-30%, an ultrathin boron nitride (BN) layer is covered on the surface, the catalyst has a core-shell structure, and a molar ratio y/x of the BN to the metal nanoparticles is 0.1-10; with the application of the catalyst in the methane preparation reaction through the hydrogenation of the catalytic synthesis gas, the sintering and the loss of the metal nanoparticles can be prevented, and the catalyst deactivation caused by the carbon deposition on the catalyst active site surface can be prevented with the core-shell structure; and the catalyst has high low-temperature activity and high high-temperature stability.

The present invention provides an exhaust gas purifying catalyst and a process for producing a metal oxide particle comprising multiple species of metal oxides and capable of satisfactorily exerting the properties of respective metal oxides. A process of the present invention comprises providing a sol containing at least a population of first colloid particles and a population of second colloid particles differing in the isoelectric point with each other; adjusting the pH of the sol to be closer to the isoelectric point of the population of first colloid particles than to the isoelectric point of the population of second colloid particles, thereby aggregating the population of first colloid particles; adjusting the pH of the sol, thereby aggregating the population of second colloid particles onto the population of first colloid particles aggregated; and drying and firing the obtained aggregate.

The invention discloses an acetylene selective hydrogenation catalyst and a preparation method and application thereof. The catalyst comprises a carrier and active metal components supported on the carrier, wherein the main active metal component palladium is elemental palladium under the conditions of room temperature and air and is prepared by reducing a palladium precursor supported on the carrier through ionizing radiation. The catalyst can be directly used in hydrogenation reaction without reduction in advance by hydrogen; the active ingredients have uniform particle size; and the catalyst has higher activity and selectivity compared with catalysts prepared by the conventional methods.

A catalyst composition for facilitating the oxidation of soot from diesel engine exhaust is provided. The catalyst composition includes a catalytic metal selected from Pt, Pd, Pt—Pd, Ag, or combinations thereof, an active metal oxide component containing Cu and La, and a support selected from alumina, silica, zirconia, or combinations thereof. The platinum group metal loading of the composition is less than about 20 g/ft³. The catalyst composition may be provided on a diesel particulate filter by impregnating the filter with an alumina, silica or zirconia sol solution modified with glycerol and/or saccharose, impregnating the filter with a stabilizing solution, and impregnating the filter with a solution containing the active metal oxide precursor(s) and the catalytic metal precursor(s). The resulting catalyst coated diesel particulate filter provides effective soot oxidation, exhibits good thermal stability, has a high BET surface area, and exhibits minimal backpressure.