7629results about "Molecular sieve catalysts" patented technology

A composition of matter is provided comprising hierarchically ordered crystalline microporous material having well-defined long-range mesoporous ordering of lamellar symmetry. The composition possesses mesopores having walls of crystalline microporous material and a mass of mesostructure between mesopores of crystalline microporous material. Long-range ordering is defined by presence of secondary peaks in an X-ray diffraction (XRD) pattern and / or lamellar symmetry observable by microscopy.

The invention relates to a preparation method of silica gel microspheres used as a catalyst carrier, which comprises the following steps of: adjusting the speed of converting acidified water glass into gel by means of controlling material temperature and material concentration, multiple times of acidification and the like, so that the acidified water glass is atomized to form liquid drops, and then the liquid drops are quickly converted into the gel; and carrying out aging, acid washing, water washing, supercritical carbon dioxide drying, roasting in an atmosphere furnace and the like to prepare the silica gel microspheres with high specific surface area and large pore volume. Compared with the prior art, the specific surface area of the obtained silica gel can reach 250-450 m < 2 > / g, the pore volume can reach 1.5-3.0 cm < 3 > / g, and the silica gel has good strength and fluidity.

The invention relates to an SSZ-39 molecular sieve and preparation and application thereof.The preparation method comprises the following steps that 1, after water, an alkali source and a template agent are mixed, mesoporous Y zeolite and a silicon source are added, the mixture is stirred to be uniform, and the mixture is aged to be in a white gel shape; (2) transferring the obtained white gel into a reaction kettle, carrying out crystallization treatment, and filtering, washing, drying and calcining a crystallized product to obtain a Na-SSZ-39 molecular sieve; (3) carrying out ammonium ion exchange on the Na-SSZ-39 molecular sieve, filtering, washing, drying and calcining to obtain an H-SSZ-39 molecular sieve; and (4) carrying out copper ion exchange on the H-SSZ-39 molecular sieve, filtering, washing, drying and calcining to obtain the Cu-SSZ-39 catalyst. Aluminum used in the method is provided by mesoporous Y zeolite, the pure-phase SSZ-39 molecular sieve can be synthesized in a wide gel range, the crystallization time is shortened to 24 h, and after copper ion exchange, the pure-phase SSZ-39 molecular sieve shows high denitration activity in the selective catalytic reduction reaction of nitrogen oxide ammonia.

The invention discloses a preparation method of an adsorption and reduction bifunctional catalyst for denitration of tail gas of a diesel vehicle. The preparation method comprises the following steps: uniformly loading a Pd component and a Cu component on the surface of a molecular sieve to prepare a corresponding Pd-based molecular sieve and a corresponding Cu-based molecular sieve; and then coupling the Pd-based molecular sieve and the Cu-based molecular sieve according to a certain proportion by using a solid-phase grinding means to obtain the adsorption and reduction dual-functional Pd-Cu / SSZ-13 catalyst. The adsorption and reduction bifunctional Pd-Cu / SSZ-13 catalyst prepared by the method not only has excellent SCR activity at the temperature of 200 DEG C or above, but also has good PNA capacity at the temperature of 200 DEG C or below, can realize high-efficiency denitration of diesel vehicle tail gas in a full-temperature section, and can be widely applied to a diesel vehicle tail gas after-treatment system.

The invention discloses a method for synthesizing tetrahydrofuran from furfural in one step and a preparation method of a catalyst for the tetrahydrofuran. The catalyst is a bimetallic catalyst, bimetallic is M1 and M2, M1 is Pd, and M2 is selected from one of Pt, Rh, Ru, Ni, Cu, Co, Mn and Ce; the catalyst comprises an active component and a carrier, the bimetallic is the active component, and the carrier is selected from at least one of activated carbon, silicon dioxide, aluminum oxide, magnesium oxide, an S-1 molecular sieve, a ZSM-5 molecular sieve, a Beta molecular sieve, an MOR molecular sieve and a Y molecular sieve; based on the total weight of the catalyst, the loading capacity of M1 is 0.5-3.5%, and the loading capacity of M2 is 0.5-3.5%. The catalyst provided by the invention can be used in a reaction for preparing tetrahydrofuran through furfural hydrogenation, and can improve the conversion rate of furfural and the selectivity of tetrahydrofuran.

Disclosed in the present invention is a method for co-producing 3,3,3-trifluoropropene and 2,3,3,3-tetrafluoropropene. The method comprises: introducing 1,1,1,3-tetrachloropropane, 1,1,1,2,3-pentachloropropane, and hydrogen fluoride into a first reactor, and reacting under the action of a first catalyst to obtain a first reactor reaction product; performing rectification on the first reactor reaction product to obtain a 3,3,3-trifluoropropene product and a tower kettle product, mixing the tower kettle product with hydrogen fluoride, and then introducing the mixture into a second reactor, and reacting under the action of a second catalyst to obtain a second reactor reaction product; and separating the second reactor reaction product from hydrogen chloride, water washing, alkaline washing, and drying to obtain a 2,3,3,3-tetrafluoropropene product. The present invention has the advantages of simple process, high efficiency, flexible operation, low investment, and low energy consumption.

A light hydrocarbon aromatization catalyst capable of increasing the yield of light alkane comprises a hydrogen type Silicalite-1 (at) ZSM-5 core-shell molecular sieve, an active metal and / or a binder, the hydrogen type Silicalite-1 (at) ZSM-5 core-shell molecular sieve takes a Silicalite-1 molecular sieve as a core layer and a ZSM-5 molecular sieve as a shell layer, and the particle size of the hydrogen type Silicalite-1 (at) ZSM-5 core-shell molecular sieve is 90-140 nm. The catalyst is applied to light hydrocarbon aromatization reaction, has higher low-carbon alkane yield and lower dry gas yield, and is good in stability, long in one-way reaction period and low in carbon deposit amount.

An article for joule heating is described, including a three-dimensional substrate on and / or in which a pyrolyzate of a phenolic resin or polymer forms an electrically conductive carbon network. Such articles may be incorporated in structured materials applications, which may include support, sorbent, and or catalyst components. Also described are methods of fabricating such articles and structured materials, and apparatus comprising same, and methods of use of such articles and structured materials and apparatus for conducting material transformation processes requiring input of heat for their performance, such as CO2 adsorption, methane pyrolysis for hydrogen and carbon production, hydrogen-assisted conversion of CO2 to hydrocarbons, including catalytic conversion of CO2 to olefins, catalytic conversion of CO2 to propane (liquefied petroleum gas), and catalytic conversion of CO2 to renewable natural gas, reverse water gas shift reaction, steam ethane cracking, propane cracking, steam methane reforming, and dry methane reforming.

The invention discloses a supported nickel catalyst for preparing 1, 3-propylene glycol through hydrogenation of 3-hydroxypropionaldehyde as well as a preparation method and application of the supported nickel catalyst, and relates to the technical field of catalysts. The modified long-chain multi-carbon inducer is used, and a special long-chain molecular structure and a branched chain group of the inducer can effectively and selectively adsorb and occupy a micropore impregnation site; the preparation method has the beneficial effects that more active component nickel species are obviously promoted to be dispersed in main reaction confinement spaces such as mesopores and macropores and interact with the carrier to form effective active sites, and active component steeping liquor is inhibited from entering micropore channels due to capillary action; the active site failure caused by agglomeration of nickel species in micropores in the subsequent drying and roasting process of the catalyst precursor is avoided, the efficient and directional reaction is ensured, the generation of by-products is greatly reduced, the pressure is relieved for the subsequent product rectification separation, and the final product purity is improved. The catalyst provided by the invention can still keep an excellent catalytic effect when the air speed of a 3-hydroxypropionaldehyde solution is increased to 6.5 h <-1 >.

The invention relates to the technical field of molecular sieves, in particular to a catalyst hydrogen type H-ZSM-5 molecular sieve for cyclohexanol preparation through cyclohexene hydration as well as a preparation method and application of the catalyst hydrogen type H-ZSM-5 molecular sieve. The molecular sieve is based on organic amine as a template agent, a ZSM-5 molecular sieve is prepared through boron isomorphous substitution, sodium ion is exchanged into protons through acid exchange, meanwhile, boron is removed, the hydrogen type H-ZSM-5 molecular sieve with the acid property is prepared, and the hydrogen type H-ZSM-5 molecular sieve serves as a catalyst to be used for a reaction for preparing cyclohexanol through cyclohexene hydration. The method comprises the following steps: adding a boron-containing reagent into synthetic gel for preparing a ZSM-5 molecular sieve for preparing cyclohexanol by hydrating cyclohexene, synthesizing the ZSM-5 molecular sieve by adopting a hydrothermal crystallization method, removing an organic template agent through programmed roasting, exchanging boron and sodium in an acid exchange process, and filtering and washing to obtain the hydrogen-type H-ZSM-5 molecular sieve. The obtained hydrogen type H-ZSM-5 molecular sieve is used as a catalyst for a reaction of preparing cyclohexanol by cyclohexene hydration, so that the yield of cyclohexanol reaches about 11.5%.

The present application relates to a phosphorus-aluminum sol, a preparation method therefor, and a use thereof as a binder in a hydrocarbon oil conversion catalyst. The present application also relates to a hydrocarbon oil conversion catalyst, a preparation method therefor, and a hydrocarbon oil catalytic conversion method using the catalyst. The phosphorus-aluminum sol provided by the present application has an appropriate colloidal particle size, a high degree of polymerization, high stability, and good adhesion, when used in a catalyst containing a molecular sieve, such as an FCC catalyst, the phosphorus-aluminum sol can reduce the blockage of molecular sieve pores, and when synergizing with other matrix materials in the catalyst, the phosphorus-aluminum sol can improve hydrothermal stability, catalytic performance and mechanical strength of the catalyst.

The invention discloses a Pt-loaded hierarchical pore HY molecular sieve double-effect catalyst and a preparation method and application thereof.The preparation method comprises the steps that firstly, an acid solution and an HY molecular sieve are mixed, heated and stirred, and the hierarchical pore HY molecular sieve is obtained; then, Pt salt is loaded on the hierarchical pore HY molecular sieve through an impregnation method, and the hierarchical pore HY molecular sieve is dried, calcined and then reduced. The concentration of the acid solution is not higher than 0.1 mol / L; the catalyst is used for hydrocracking of polyethylene or polypropylene. According to the Pt-loaded hierarchical pore HY molecular sieve double-effect catalyst disclosed by the invention, Pt atoms have excellent C-H bond activation capability, meanwhile, the hierarchical pore HY molecular sieve carrier has an open connection mesoporous structure and an acid site, and the mesoporous structure constructed by acid pickling and dealumination is beneficial to diffusion of a reaction intermediate and improvement of the yield of a liquid product; more orifice acid can be exposed by surface erosion, so that the initial cracking of reaction raw materials is facilitated, and the catalytic performance is improved.

The invention relates to an acrylonitrile catalyst and a preparation method and application thereof, and belongs to the field of chemical engineering, and the preparation method comprises the following steps: (1) mixing solutions of molybdenum and bismuth compounds according to a Mo / Bi molar ratio of 0.5-1.5 to prepare bismuth molybdate containing an alpha phase and / or a gamma phase; (2) synthesizing a pentasil type molecular sieve with a Si / V molar ratio of 50-150 by using a silicon source, organic amine and a vanadium compound; (3) mixing the silica sol and the molybdenum compound solution according to the molar ratio of Si to Mo of 0.5-1, and then sequentially adding the solution of nickel, tungsten and thallium compounds, phosphoric acid, a molecular sieve and bismuth molybdate, so that the weight ratio of Mo to Bi to Ni to W to Tl to V to P in the catalyst is (37-38): (4-6): (3-5): (2-3): (0.2-0.3): (0.1-0.3): (0.7-0.8) according to the percentage weight of oxides; (4) adding SiO2 powder, wherein SiO2 in the catalyst accounts for 45 wt%-55 wt%; and (5) after pulping and homogenizing, carrying out spray molding at an outlet temperature of 150-180 DEG C, and roasting for 1-6 hours in an air atmosphere at 550-680 DEG C. The catalyst has good activity, selectivity and stability and is wear-resistant.

The invention relates to the technical field of ZSM-5 molecular sieve preparation, and provides a high-crystallinity aluminum-rich ZSM-5 molecular sieve as well as a preparation method and application thereof. According to the preparation method of the high-crystallinity aluminum-rich ZSM-5 molecular sieve provided by the invention, after the second aluminum source is added, secondary crystallization is carried out, so that the skeleton composition control of the ZSM-5 molecular sieve is realized, the technical bottleneck that the high-crystallinity aluminum-rich ZSM-5 molecular sieve is difficult to directly synthesize is solved, the lower limit of a Si / Al specific phase region of an artificial in-situ synthesized molecular sieve is broken through, and the preparation method is simple and convenient. The method effectively controls crystal parameters, improves production efficiency and realizes precise construction of the high-crystallinity aluminum-rich ZSM-5 molecular sieve, so that the microporous crystallinity of the molecular sieve is enhanced, the acid distribution of the molecular sieve is optimized, the metastable state surface active acid center distribution of the molecular sieve is greatly enriched, and the molecular sieve has good aromatic hydrocarbon conversion performance.

The present invention provides a method for preparing a multi-level porous composite molecular sieve, comprising the following steps: S1) mixing a binder, a carrier, a mesoporous directing agent and water, and spraying to obtain microspheres; S2) mixing the microspheres with a silicon source, an aluminum source and a mesoporous directing agent after calcination, and calcining and activating again; S3) mixing the microspheres obtained in step S2) with a template agent and water for synthesizing a ZSM-5 molecular sieve, and calcining the solid product obtained after crystallization to obtain a multi-level porous composite molecular sieve. The present application also provides a multi-level porous composite molecular sieve and its application. The composite molecular sieve provided in the present application can be applied to fields such as heavy oil catalytic cracking, effectively improving the diffusion of catalyst acid sites and substrate molecules and product molecules in the reaction, improving the reaction conversion rate and inhibiting coke formation.

The invention provides a high-stability in-situ crystallization catalyst as well as a preparation method and application thereof, and belongs to the technical field of oil refining catalysts. The preparation method comprises the following steps: firstly preparing kaolin microspheres, then roasting the kaolin microspheres into high soil balls and partial soil balls, and mixing the high soil balls and partial soil balls with a silicon source, sodium hydroxide, a seed crystal and a silicon-aluminum activator for in-situ crystallization, so that not only is the activation degree of silicon dioxide in kaolin promoted, but also the timely insertion of active silicon species into a NaY zeolite skeleton in the crystallization process is accelerated, and the activity of the NaY zeolite is improved. The high-stability in-situ crystallization catalyst is prepared by carrying out ammonium salt and rare earth exchange, roasting and phosphorus or boron modification treatment on the crystallized microspheres, and has the characteristics of strong heavy oil conversion and metal pollution resistance and high total liquid yield when being used for catalyzing heavy oil cracking.

The invention discloses a pure silicon Beta molecular sieve packaging metal catalyst and a preparation method and application thereof, and the preparation method comprises the following steps: dissolving a silicon source, a template agent, a ligand, a metal salt and a mineralizer in water, carrying out a crystallization reaction at 120-200 DEG C, and carrying out calcination treatment and reduction treatment on the crystallized solid to obtain the pure silicon Beta molecular sieve packaging metal catalyst. The pure silicon Beta molecular sieve packaged metal catalyst is obtained. The pure silicon twelve-membered ring macroporous Beta molecular sieve encapsulated metal catalyst is prepared through a ligand protection in-situ hydrothermal synthesis strategy, so that the size of a metal nanocluster can be reduced, the high-temperature thermal stability of the metal nanocluster is improved, the adsorption and diffusion processes of guest molecules can be regulated and controlled, and the stability of the metal nanocluster is improved. Furthermore, the catalyst shows excellent catalytic performance when being used for catalyzing a propane dehydrogenation reaction and a methyl cyclohexane dehydrogenation reaction, and efficient and stable propane and methyl cyclohexane dehydrogenation performance is achieved.

The invention discloses a catalyst for synthesizing low-carbon olefin through CO2 hydrogenation reaction as well as preparation and application of the catalyst. The catalyst comprises an active component A and a core-shell structure B (at) C, wherein the active component A is a metal oxide with catalytic activity for synthesizing low-carbon olefin through a CO2 hydrogenation reaction; in the core-shell structure B (at) C, B is an SAPO molecular sieve, and C is selected from one or more of B2O3, SiO2, Al2O3, TiO2, ZrO2, kaolin and montmorillonite. The catalyst is used for synthesizing low-carbon olefin through CO2 hydrogenation, and can obviously improve the CO2 conversion efficiency and reduce the CO selectivity.

Methods for upgrading heavy aromatic waste streams, such as polystyrene, to chemical feedstocks are disclosed. The process involves feeding waste streams to a first pyrolysis zone followed by hydrogenation. The hydrogenation effluent is processed to recover ethylene, propylene, benzene, ethylbenzene, or their precursors. Optionally, the effluents are separated into light and heavy streams. The light stream from the first pyrolysis effluent is sent to hydrogenation, while the heavy stream is either removed, recycled to the first pyrolysis zone, or fed to a second pyrolysis zone. The light stream from the hydrogenation effluent is processed to recover the same chemicals, and the heavy stream is similarly managed. If present, the second pyrolysis effluent is separated into light and heavy streams, with the light stream processed to recover chemicals and the heavy stream managed as before.

The invention discloses a preparation method and application of a mesoporous confinement nickel-based methane dry reforming catalyst, and belongs to the field of nano-catalyst preparation.According to the method, on the basis of a traditional impregnation method, a small amount of ethylene glycol is added to serve as a surface active agent, high-temperature-resistant SBA-15 with ordered mesoporous channels serves as a carrier, metal nitrate serves as a precursor, and the mesoporous confinement nickel-based methane dry reforming catalyst is prepared through a hydrothermal method; in the high-speed stirring evaporation process, along with evaporation of water, the surface tension of the mixed liquid is gradually reduced, and meanwhile, the viscosity of the solution is increased, so that the metal nitrate precursor can be conveyed into an SBA-15 pore channel and is anchored in the pore channel under the action of high viscosity. And the methane dry reforming catalyst with high activity and high stability is obtained through drying, calcining and hydrogen reduction. The catalyst has the advantages of simple preparation process, low cost, high catalytic efficiency, high stability and the like.

The invention discloses a metal particle Ni supported catalyst based on fly ash. The preparation method comprises the following steps: firstly, carrying out alkali fusion on fly ash to prepare powder; dissolving the powder and Ni (NO3) 2.6 H2O in a mixed solution of distilled water and absolute ethyl alcohol, adding polyethylene glycol, and performing ultrasonic stirring to obtain uniform dispersion liquid; and finally, continuously performing ultrasonic stirring on the dispersion liquid, performing hydrothermal reaction, cooling, performing centrifugal separation, drying, calcining, cooling and grinding to obtain the catalyst. The coal ash derivative zeolite is adopted as a carrier of the catalyst, Ni is loaded on the carrier to improve the specific surface and effective active sites of the carrier, the effective catalytic specific surface area of the catalyst is effectively improved, and the catalytic activity is improved, so that a stable and safe catalyst material for preparing methane through CO2 hydrogenation with high activity and selectivity is obtained; the space time yield of methane is high.

The invention discloses a nickel-samarium bimetallic synergistic / MCM-41 molecular sieve catalyst as well as a preparation method and application thereof. The catalyst comprises a carrier and active components loaded on the carrier, the carrier is an MCM-41 molecular sieve, and the active components are nickel and samarium. Compared with other nickel-based catalysts, the catalyst disclosed by the invention has the advantages that through the synergistic effect of nickel and samarium bimetals, the interaction between the active component and the carrier is enhanced, the dispersion degree of the active metal is improved, and the anti-sintering capability of the active metal is enhanced; and the surface of the catalyst has high oxygen vacancy concentration, so that the activation of CO2 is promoted, the number of active oxygen species on the surface of the catalyst is increased, and the removal of deposited carbon is promoted. Therefore, the catalyst has good sintering resistance and carbon deposition resistance and high catalytic stability, and meets the use requirements of industrial catalysts.

The invention provides a VOCs catalyst as well as a preparation method and application thereof, and belongs to the field of atmosphere prevention and control. The invention provides a VOCs (Volatile Organic Compounds) catalyst. The VOCs catalyst comprises a modified ZSM-5 zeolite molecular sieve and active metal and / or oxide of the active metal loaded on the modified ZSM-5 zeolite molecular sieve, the preparation method of the modified ZSM-5 zeolite molecular sieve comprises the following steps: mixing a ZSM-5 zeolite molecular sieve and an organic alkali solution, and carrying out a hydrothermal reaction to obtain an organic alkali-loaded ZSM-5 zeolite molecular sieve; and roasting the ZSM-5 zeolite molecular sieve loaded with the organic alkali, and removing the organic alkali to obtain the modified ZSM-5 zeolite molecular sieve, the organic alkali solution is a tetrapropylammonium hydroxide solution.

The application provides a method for grading diesel deep hydrodesulfurization catalysts, which comprises the following steps: loading catalysts containing AlPO4-5 phosphorus aluminum molecular sieves and catalysts containing ETS-10 titanium silicon molecular sieves in the upper and lower parts of a fixed bed hydrogenation reactor respectively according to a loading mass ratio of 1:3-3:1, so that diesel is subjected to hydrodesulfurization reaction through catalysts containing AlPO4-5 phosphorus aluminum molecular sieves first and then through catalysts containing ETS-10 titanium silicon molecular sieves; the carrier of the catalysts containing AlPO4-5 phosphorus aluminum molecular sieves comprises AlPO4-5 phosphorus aluminum molecular sieves and aluminum oxide powder, the carrier of the catalysts containing ETS-10 titanium silicon molecular sieves comprises ETS-10 titanium silicon molecular sieves and aluminum oxide powder, and the active components of the two kinds of catalysts respectively comprise a combination of two or three of nickel oxide, molybdenum oxide and cobalt oxide. The sulfur content of the hydrogenated diesel obtained through the method can be as low as 10 μg / g or below.

The invention discloses a preparation method of a mesoporous Zn-ZSM-5 molecular sieve for preparing aromatic hydrocarbon from methanol, and belongs to the technical field of synthesis of inorganic materials. Aiming at the problems that a conventional mesoporous Zn / ZSM-5 molecular sieve catalyst Zn blocks orifices, the mesoporous structure is disordered, the molecular sieve solid yield is low, a molecular sieve framework is seriously damaged and the like, the preparation method comprises the following steps: uniformly mixing zinc gluconate with an aluminum source, a silicon source and a template agent, putting the mixture into a closed reaction container, carrying out hydrothermal crystallization, and sequentially washing, drying and roasting to obtain the mesoporous Zn / ZSM-5 molecular sieve catalyst. The sodium type molecular sieve is obtained; the preparation method comprises the following steps: carrying out multiple ion exchange on a sodium type molecular sieve by using an ammonium chloride solution, and sequentially carrying out suction filtration, washing, drying and roasting to obtain the mesoporous Zn-ZSM-5 molecular sieve. According to the preparation method of the methanol-to-aromatic hydrocarbon Zn / ZSM-5 molecular sieve provided by the invention, the obtained molecular sieve is used in the methanol-to-aromatic hydrocarbon process, and has the characteristics of high carbon deposition resistance, high aromatic hydrocarbon selectivity, low Zn wastage rate and the like.

The invention discloses a Fe-Beta molecular sieve for N2O catalytic decomposition and a preparation method of the Fe-Beta molecular sieve. According to the method, chitosan and metal Fe < 3 + > ions are complexed to form a chitosan Fe < 3 + > complex, and then the complex, a silicon source, an aluminum source and a template agent are used as raw materials to prepare the Fe-Beta molecular sieve in one step through a hydrothermal method. Hydroxyl, amino and other groups rich in a chitosan molecular chain can effectively complex metal Fe < 3 + > ions to form a stable chitosan Fe < 3 + > complex, and the stable chitosan Fe < 3 + > complex is used as a Fe source to realize uniform dispersion of Fe species in the molecular sieve and effectively reduce formation of FexOy clusters and Fe2O3 nanoparticles, so that the N2O decomposition catalytic performance of the Fe-Beta molecular sieve is improved. Inorganic alkali metal ions are not introduced, so that a large amount of ammonia-nitrogen wastewater generated in a subsequent tedious ammonium exchange process can be avoided, the synthesis period is effectively shortened, and energy consumption, material consumption and environmental pollution are reduced.

The invention provides a Pt-Sn bimetallic catalyst and a preparation method and application thereof.The preparation method comprises the steps that 1, a Y molecular sieve is placed in a mixed solution of KOH and methyl alcohol, centrifugation and washing are conducted till the Y molecular sieve is neutral after stirring, drying and roasting are conducted, and a non-acid KY molecular sieve is obtained; the silica-alumina ratio of the Y molecular sieve is 3-100; 2) taking the non-acidic KY molecular sieve as a carrier, and loading Sn by adopting an atomic layer deposition technology to obtain a Sn-modified non-acidic KY molecular sieve; and 3) loading Pt by using the Sn-modified non-acidic KY molecular sieve as a carrier and adopting an atomic layer deposition technology to obtain the Pt-Sn bimetallic catalyst. According to the preparation method provided by the invention, spatial distribution of Pt and Sn is accurately regulated and controlled by combining an atomic layer deposition technology, so that the electronic state of Pt species is adjusted, alkane is promoted to be dehydrogenated into an olefin intermediate, and the aromatization catalytic activity and the aromatic hydrocarbon selectivity of alkane are improved.

The invention provides a preparation method and application of a catalyst for methane normal hexane co-aromatization, a simple in-situ hydrothermal synthesis method is adopted, platinum and nickel are dispersed in a ZSM-5 molecular sieve, and a metal packaging type NiPt-coated ZSM-5 catalyst is synthesized. When the catalyst is applied to methane and normal hexane co-aromatization reaction, the catalyst shows relatively high methane conversion rate and aromatic hydrocarbon selectivity. The molecular sieve packaging mode not only can improve the dispersity of the active component so as to improve the capability of activating methane, but also can improve the high-temperature stability of the active component and prolong the service life of the catalyst, and can effectively solve the problems of high reaction temperature and poor catalyst stability in the existing methane aromatization technology. And the method has a good practical application prospect.

The invention discloses a method for performing tar steam reforming by coupling low-temperature plasma with a nickel-loaded hydrogen type molecular sieve composite catalyst. The method comprises the following steps: preparing the nickel-loaded hydrogen type molecular sieve composite catalyst; the mass of Ni in the nickel-loaded hydrogen type molecular sieve composite catalyst accounts for 5-30% of the mass of the catalyst; introducing tar and water vapor into a dielectric barrier discharge plasma reactor filled with the nickel-loaded hydrogen type molecular sieve composite catalyst; starting the dielectric barrier discharge plasma reactor, and carrying out a tar steam reforming reaction; wherein the temperature of the tar steam reforming reaction is 150-525 DEG C, and the power of the tar steam reforming reaction is 30-90 W. The catalyst disclosed by the invention is coupled with a low-temperature plasma technology, so that good tar reforming performance, target product selectivity and system stability are realized.

The invention discloses a monatomic catalyst capable of retaining surface defects of a catalyst as well as a preparation method and application of the monatomic catalyst, and belongs to the field of catalysis. The monatomic catalyst comprises an active metal component, a doping element and a carrier, the carrier is a semiconductor material rich in surface defects. The preparation method adopts a light-induced migration-conversion strategy. The monatomic catalyst which is obtained by the preparation method and retains the surface defects of the semiconductor material is applied to the fields of photocatalysis, thermocatalysis and electrocatalysis, and shows excellent performance.