43 results about "Alkene epoxidation" patented technology

This invention belongs to the field of catalyst technology and discloses a catalyst for olefin epoxidation, its preparation method, and its application. The preparation method includes: (1) preparing a mixture containing a silver compound precursor, an organic amine, water, and optional auxiliary agents to obtain a silver-containing mixture; (2) fully contacting the silver-containing mixture with an alumina support, and leaching off excess mixture from the surface of the support to obtain a support carrying the silver-containing mixture; (3) irradiating the support carrying the silver-containing mixture with microwaves to obtain the catalyst. The olefin epoxidation catalyst prepared by the method of this invention avoids local overheating during the preparation process, improves the dispersion of active centers, and thus has excellent catalytic performance.

The invention discloses a TS-1 molecular sieve catalyst, a preparation method and application of the TS-1 molecular sieve catalyst in preparation of an epoxy compound through epoxidation of hydrogen peroxide and alkene, the preparation method comprises the following steps: mixing a template agent with water, and then adding a silicon source to obtain a first solution; mixing a titanium source, soluble vanadium salt and isopropanol to obtain a second solution; stirring and mixing the first solution and the second solution, then adding octadecylamine polyoxyethylene ether biquaternary ammonium salt to obtain a reaction system, and then performing crystallization, separation and heat treatment to obtain the TS-1 molecular sieve catalyst. Through doping of vanadium heteroatoms and adjustment of octadecylamine polyoxyethylene ether biquaternary ammonium salt on a crystallization process, a hierarchical pore system is successfully constructed while high-activity titanium species are retained, and collaborative optimization of a pore structure and active sites is realized. The TS-1 molecular sieve catalyst obtained through optimization shows significantly enhanced catalytic activity and selectivity in an olefin epoxidation reaction system.

The invention relates to the technical field of heterogeneous catalysts, and particularly discloses a catalyst for catalyzing long-chain alpha-olefin epoxidation reaction and a preparation method and application thereof.The catalyst is a supported metal catalyst and comprises an active component, an auxiliary and a molecular sieve carrier, the active component is Sn element, the auxiliary is one or more of Zn, Zr and Ga, and the molecular sieve carrier is a molecular sieve carrier. The molecular sieve carrier is a dealumination Beta molecular sieve with a * BEA topological structure; the mass content of the active component accounts for 10-20wt% of the molecular sieve carrier; according to the present invention, the Sn element is adopted as the active component, the auxiliary agent and the molecular sieve carrier are combined to form the new long carbon chain alpha-olefin epoxidation catalytic system, and the heterogeneous catalyst can catalyze the long chain alpha-olefin to prepare the high carbon epoxide, and has advantages of high catalytic activity, high target product selectivity and the like.

The invention belongs to the technical field of chemical synthesis, and discloses a method for synthesizing fatty diol from straight-chain fatty olefin through a one-pot method under catalysis of titanium silicalite molecular sieve loaded sulfate. Through metal sulfate modification, acid sites on the surface of the titanium silicalite molecular sieve are increased, so that the catalytic epoxidation function of tetra-coordinated titanium and the catalytic hydrolysis function of the acid sites have a synergistic effect, and olefin epoxidation-epoxide hydrolysis reactions are connected in series. According to the process, olefin can be almost completely converted, and the problem of raw material recovery does not need to be considered. The bifunctional catalyst is used for preparing 1, 2-pentanediol from 1-pentene through a one-pot method, the conversion rate of 1-pentene is larger than 98%, the yield of 1, 2-pentanediol is larger than 77%, intermediate separation and additional acid and alkali are not needed in the whole process, the equipment corrosion risk is reduced, the problems of environmental pollution and complex process of a traditional process are solved, and the catalyst can be recycled and reused for multiple times.

The present application relates to the technical field of catalyst, in particular to a preparation method of TS-1 molecular sieve for olefin epoxidation; the main preparation method is as follows: tetraethyl orthosilicate is added dropwise into an aqueous solution containing tetrapropylammonium hydroxide; after the solution is clarified, a solution containing tetrabutyl titanate and isopropanol is added dropwise; after hydrolysis is completed, guanidine acetate is added; the precursor solution is obtained after stirring at a certain temperature for a period of time; the obtained solution is loaded into a kettle, and the crystallization product is obtained after hydrothermal crystallization; finally, the sheet-shaped TS-1 molecular sieve is obtained through centrifugation, drying and calcination; the present application has low cost, simple operation, short synthesis period, small size in the b-axis direction, improved diffusion mass transfer rate, and good catalytic activity in 1-hexene epoxidation, cyclohexene epoxidation, propylene epoxidation, chloropropylene epoxidation and phenol hydroxylation reaction.

The invention belongs to the technical field of preparation of epoxy compounds, and relates to an olefin epoxidation method. According to the method, reaction raw materials containing olefin and hydrogen peroxide are subjected to a reaction on a fixed bed reactor using a forming catalyst formed by compounding a titanium silicalite molecular sieve and an organic matter carbonized product. The catalyst is obtained by extrusion molding, drying and carbonization of a mixture containing a titanium silicalite molecular sieve, a benzene ring-containing polymer and a dispersing agent, the obtained catalyst has high mechanical strength and is suitable for olefin epoxidation fixed bed reaction. The method provided by the invention can effectively inhibit formation of byproducts, and realizes efficient utilization of hydrogen peroxide and efficient proceeding of olefin epoxidation reaction.

The invention relates to a preparation method of an oxygen-vacancy-rich double-phase tungsten oxide WO3H2O / WO2.72 and application of the oxygen-vacancy-rich double-phase tungsten oxide WO3H2O / WO2.72 in olefin epoxidation reaction. The preparation method of the oxygen-vacancy-rich double-phase tungsten oxide WO3H2O / WO2.72 comprises the following steps that WCl6 and absolute ethyl alcohol are placed in a container according to the molar ratio of 0.003-0.005: 1, stirred to be dissolved and then transferred into a self-pressure reaction kettle; the preparation method comprises the following steps: adding WO3H2O and WO2.72 into a reaction kettle, reacting for 7-11 hours at 120-160 DEG C under dynamic stirring at 40-100 r / min, cooling, centrifuging or carrying out suction filtration, washing the obtained product with pure water and absolute ethyl alcohol for 3-4 times in sequence, and drying for 3-10 hours at 40-80 DEG C to obtain the dark blue double-phase tungsten oxide WO3H2O / WO2.72 with a flower-like nano hierarchical structure, WO3H2O and WO2.72 coexist in two phases, the content of W < 5 + > reaches 9-15%, the content of oxygen vacancy reaches 15-25%, and the specific surface area is 35-90 m < 2 > / g. The preparation method disclosed by the invention is simple, the process is easy to control, the repeatability is good, the prepared double-phase tungsten oxide WO3H2O / WO2.72 has a good catalytic effect in olefin epoxidation reaction, the cyclooctene conversion rate of the reaction at 60 DEG C for 6 hours is greater than 96%, and the selectivity of epoxy cyclooctane is greater than 99%.

The preparation method comprises the following steps: mixing a Ti-Beta molecular sieve, water, tetrapropylammonium hydroxide, tetrabutyl titanate and modified porous carbon, then carrying out a crystallization reaction, collecting insoluble substances, and carrying out calcination treatment, the titanium-silicon catalyst for catalyzing the olefin epoxidation reaction is obtained. According to the invention, a structure-directing agent tetrapropylammonium hydroxide is introduced on the basis of the Ti-Beta molecular sieve, modified porous carbon is also introduced when tetrapropylammonium hydroxide and tetrabutyl titanate are used for treatment, carbon components of the modified porous carbon are removed during high-temperature calcination, and metal components are combined with the molecular sieve in situ, so that pore diameters in a composite structure are richer, and a Ti active center is easier to expose. The titanium-silicon catalyst constructed by the invention has good catalytic activity and selectivity on olefin epoxidation reaction, and also has good reproducibility.

A composition of matter useful for catalyzing an alkene epoxidation reaction using molecular oxygen (O2) as an oxidant. including a plurality of structures comprising nanostructures or microstructures each comprising a coinage metal: and a plurality of single oxophilic metal atoms. The oxophilic metal is characterized by an oxide formation enthalpy being more exothermic than that of the coinage metal. In one or more examples. the oxophilic atom comprises nickel and the coinage metal comprises silver, and a concentration of the nickel increases selectivity to greater than 85% for the epoxidation reaction CH2═CH2+½O2→(CH2)2O over combustion of ethylene forming carbon dioxide. and for an ethylene conversion of greater than 5%.

The invention discloses a Ti-MWW molecular sieve catalyst, a preparation method and application of the Ti-MWW molecular sieve catalyst in preparation of an epoxy compound through direct epoxidation of hydrogen peroxide and olefin, and mainly relates to the technical field of molecular sieve catalysts. Compared with the prior art, the Ti-MWW molecular sieve catalyst prepared by the invention can simultaneously improve the selectivity of epoxy compounds and the conversion rate of hydrogen peroxide, can be applied to direct epoxidation reaction of hydrogen peroxide and alkene, optimizes the solvent, crystallization step and organic amine in preparation, and can better guide crystal growth in the forming process of the molecular sieve; a pore structure and an acid environment which are more beneficial to olefin epoxidation reaction are formed, the catalytic activity and selectivity to target reaction are finally enhanced, and the selectivity of epoxy compounds and the hydrogen peroxide conversion rate are improved.

The application discloses a titanium-silicon catalyst for olefin epoxidation reaction, and a preparation method and application of the catalyst. The catalyst can control the mesoporous molecular sieve material and the Ti-rich outer surface of the molecular sieve, and the active substance for olefin epoxidation reaction can be as close to the active center as possible and has small diffusion resistance and high catalytic efficiency.

The invention belongs to the field of catalysts, and relates to a method for activating a silver catalyst as well as the catalyst and application thereof. Comprising the following steps: (1) fully contacting an alpha-alumina carrier with a silver-containing impregnation liquid, and leaching to remove redundant impregnation liquid to obtain a silver catalyst precursor; and (2) the silver catalyst precursor obtained in the step (1) is subjected to infrared radiation activation treatment, and the conditions of the infrared radiation activation treatment are as follows: the air velocity is 0-5000h <-1 >, the irradiation temperature is 100-500 DEG C, and the irradiation time is 1-50min. The activation method disclosed by the invention is advanced in process, safe, environment-friendly and simple to operate, the active components and the cocatalyst of the silver catalyst are uniformly distributed, and the prepared catalyst shows more excellent activity and selectivity in olefin epoxidation reaction.

This invention relates to a cobalt-supported pachytite catalyst, its preparation method, and its application in olefin epoxidation. The method includes the following steps: pre-treated pachytite is acidified with an organic acid to obtain acidified pachytite; the acidified pachytite and a cobalt source are added to water, and a hydrothermal reaction is carried out under stirring conditions; after the reaction, post-treatment is performed, and the pachytite-supported cobalt catalyst is collected. This invention uses organic acid to treat pachytite, which helps increase the interlayer spacing of the pachytite, thereby enabling the loading of metallic cobalt and providing a favorable catalytic environment for promoting the styrene epoxidation reaction. The catalyst obtained by this invention can be recycled for olefin epoxidation, significantly increasing the conversion and selectivity of olefins and effectively reducing byproducts. Under the action of this catalyst, oxygen from the air or directly introduced oxygen can be used as the oxidant, effectively reducing costs, avoiding pollution, and preventing the introduction of other impurities, which is beneficial for product separation and results in high purity.

The application belongs to the technical field of epoxy compound preparation, and particularly relates to a titanium-silicon molecular sieve TS-1, a preparation method thereof and an olefin epoxidation method. The preparation method comprises the following steps: S1, hydrolysis dispersion: hydrolysis and dispersion of a mixture of a silicon source, a titanium source, a structure directing agent, a monosaccharide compound and water to obtain a mixed system I; S2, water-silicon ratio regulation: adding the mixed system I into a concentration kettle, reducing the water-silicon ratio of the mixed system I through distillation dehydration to obtain a mixed system II; S3, crystallization reaction: transferring the mixed system II into a closed crystallization kettle to crystallize under self-generated pressure, and finally filtering, drying and calcining to obtain the titanium-silicon molecular sieve TS-1. The monosaccharide compound introduced in the mixed system I contains rich hydroxyl groups, which can form hydrogen bond action with the silicon / titanium hydroxyl groups in the molecular sieve precursor, thereby affecting the growth process of the molecular sieve crystal grains, and on this basis, the nucleation process of the molecular sieve can be strengthened by regulating the water-silicon ratio.

The invention discloses an inorganic-organic composite metal silicate catalyst as well as a preparation method and application thereof, and is characterized in that the composition of the catalyst is xMOn / 2. Y R.1.0 SiO2, M is one or more than two metals of aluminum, iron, titanium and tin; n is the valence state of the metal M; x is the molar ratio of metal M to Si; r is cyclic organic amine with the ring number of 5-7; y is the molar ratio of the cyclic organic amine to Si; the catalyst is obtained by taking a zeolite molecular sieve as a raw material and carrying out hydrothermal reaction on the zeolite molecular sieve and a cyclic organic amine aqueous solution under high-temperature and high-pressure conditions; the catalyst is used for catalyzing a deacetalization-Kirschner condensation bifunctional cascade reaction of benzaldehyde dimethyl acetal and malononitrile and an epoxidation catalytic reaction of olefin to synthesize corresponding epoxide. Compared with the prior art, the preparation method disclosed by the invention is simple and convenient, and has the characteristics of mild reaction conditions, high target product yield and few byproducts in a deacetalization-Kirschner condensation acid-base bifunctional catalytic reaction and an olefin epoxidation catalytic reaction, and has a good application prospect.

The invention belongs to the field of silver catalysts, and relates to a silver impregnation liquid for olefin epoxidation, a preparation method of the silver catalyst for olefin epoxidation, the silver catalyst prepared by the method, and applications of the silver impregnation liquid and the silver catalyst in olefin epoxidation. The silver impregnation liquid comprises the following components: 1) a silver amine complex; 2) steeping liquor stabilizer; 3) water; 4) an optional auxiliary agent; wherein the steeping liquor stabilizer is a small molecular organic matter which has electron withdrawing capability and contains carboxyl, ester group or anhydride functional group, and the content of the steeping liquor stabilizer is 0.01-20wt% on the basis of the total weight of the steeping liquor. The stability of the silver impregnation liquid is improved, suspended zero-valent silver nanoparticles in the impregnation liquid can be greatly reduced, the size distribution condition of activated catalyst silver particles is improved, and then the selectivity and stability of the catalyst are improved.

The present invention relates to the field of olefin epoxidation reaction solvent post-treatment, and discloses an olefin epoxidation reaction solvent recycling method, which comprises: carrying out an epoxidation reaction on 3-chloropropene and an oxidizing agent in the presence of a solvent methanol to obtain an epoxidation reaction product, and carrying out extraction separation to obtain a raffinate phase; the raffinate phase is subjected to first rectification, the mass flow of methanol in tower top discharge accounts for 10% or below of the mass flow of methanol in the raffinate phase, and the mass fraction of 3-chloropropene in tower bottom discharge is smaller than 0.1%; carrying out second rectification on the material discharged from the bottom of the first rectification tower, wherein the pH value of the material discharged from the bottom of the second rectification tower is 5-8; carrying out third rectification on the material discharged from the bottom of the second rectification tower, discharging wastewater from the bottom of the tower, and returning at least part of the wastewater to the extraction; the pH value of the wastewater is 5-8; the second rectification and the third rectification are carried out in the presence of an alkaline aqueous solution. According to the method, the corrosion to equipment can be reduced, the cost is reduced, and the risk of safety accidents is reduced.

A polyacid-based supramolecular complex catalyst for catalyzing olefin epoxidation at normal temperature, a preparation method and application thereof, and a molecular formula thereof is as follows: {[Co(cmbpy)(H2O)4](beta-Mo8O 26 ) 0.5}·H2O, wherein, cmbpy is deprotonated 1-(carboxymethyl)-(4,4'-bipyridine). A cobalt sulfate, 1-(carboxymethyl)-4,4'-bipyridinium hydrochloride and (NH4)6Mo7O 24 ·4H2O are added into an ethanol solution, stirred for 2 hours, the pH value is adjusted to 5.84 by using an inorganic base, transferred to a reaction kettle with a polytetrafluoroethylene liner, sealed, heated to 85 DEG C, reacted under hydrothermal conditions for 4 days, naturally cooled to room temperature after the reaction is completed, washed and separated to obtain the polyacid-based supramolecular complex catalyst. The advantage is that the synthesis method is simple, the synthesis time is short, the synthesis yield is high, and the catalyst can be used for selective oxidation of cyclooctene.

The utility model discloses a regeneration device for an olefin epoxidation inactivated titanium silicalite molecular sieve catalyst, which comprises a methanol rectifying tower, a methanol reboiler, a methanol cooler, a catalyst acidification kettle, a methanol reflux pump, a methanol feeding pump, a fresh methanol storage tank, a bag filter and an acid liquor storage tank, the methanol reboiler is connected with the methanol rectifying tower, the methanol cooler is connected with the catalyst acidification kettle through a pipeline, the catalyst acidification kettle is connected with the methanol reflux pump through a pipeline, the methanol reflux pump is connected with the methanol rectifying tower through a pipeline, and the fresh methanol storage tank is connected with the methanol feeding pump through a pipeline. The methanol feeding pump is respectively connected with the catalyst acidification kettle and the methanol rectifying tower through pipelines, the catalyst acidification kettle is connected with the bag filter through a pipeline, the bag filter is connected with the fresh methanol storage tank through a pipeline, and a tower kettle of the methanol rectifying tower is connected with the acid liquor storage tank through a pipeline. The device is simple to operate, good in regeneration activity and high in economic benefit.

The present invention discloses a Ti-MWW molecular sieve catalyst, a preparation method, and its application in the direct epoxidation of hydrogen peroxide with olefins to prepare epoxy compounds, primarily relating to the field of molecular sieve catalyst technology. Compared with the prior art, the Ti-MWW molecular sieve catalyst prepared by the present invention can simultaneously improve epoxy compound selectivity and hydrogen peroxide conversion rate, and can be applied in the direct epoxidation reaction of hydrogen peroxide with olefins. The present invention optimizes the solvent, crystallization step, and organic amine during the preparation process to better guide crystal growth during the molecular sieve formation process, forming a pore structure and acidic environment that is more conducive to the epoxidation reaction of olefins, ultimately enhancing the catalytic activity and selectivity for the target reaction, and improving the selectivity of epoxy compounds and the hydrogen peroxide conversion rate.

The present disclosure relates to a Ti-MWW molecular sieve catalyst, its preparation method, and its application. The X-ray photoelectron energy spectrum of the catalyst contains peaks at 458.9±0.2 eV and 464.8±0.2 eV, preferably 458.9±0.2 eV, 460.3±0.2 eV, 464.8±0.2 eV, and 465.9±0.2 eV. When used in olefin epoxidation, the Ti-MWW molecular sieve catalyst exhibits advantages such as high olefin conversion, high epoxide selectivity, and good catalytic stability.

The invention relates to the field of epichlorohydrin production, and discloses a titanium silicalite molecular sieve catalyst, a preparation method and application thereof, and a method for preparing epichlorohydrin through epoxidation reaction of 3-chloropropene. The catalyst comprises a titanium silicalite molecular sieve and aluminum oxide, based on the total mass of the catalyst, the content of the titanium silicalite molecular sieve is 70-95 wt%, and the content of the aluminum oxide is 5-30 wt%; wherein the side pressure crushing strength of the catalyst is 60 to 120 N / cm. The catalyst provided by the invention has high strength and high catalytic performance, and is suitable for olefin epoxidation reaction.

The application belongs to the technical field of catalysts, and discloses an olefin epoxidation catalyst, a preparation method and application thereof, the preparation method comprising the following steps: (1) preparing a silver-containing solution, wherein the silver-containing solution comprises a silver compound precursor, an organic amine, water and an optional additive; (2) fully contacting the silver-containing solution with an alumina carrier, and draining the excess solution on the surface of the carrier to obtain a carrier loaded with the silver-containing solution; (3) treating the carrier loaded with the silver-containing solution in infrared radiation to obtain the catalyst. The olefin epoxidation catalyst prepared by the method has a significantly reduced silver content gradient inside and outside the catalyst, greatly improved activity center dispersity, reduced agglomeration and blockage of nanoparticles, and excellent catalytic performance.

This invention discloses a method for preparing epoxides through the epoxidation of olefins. The method includes contacting H₂O₂ with an olefin in a solvent in the presence of a hierarchical porous titanium-silicon molecular sieve catalyst, wherein the bulk density of the hierarchical porous titanium-silicon molecular sieve is 3.0–4.0 g / mL. This method, used in the epoxidation reaction of olefins involving H₂O₂, exhibits high activity, good stability, and good selectivity.

The present invention discloses a heterogeneous catalyst for catalyzing the epoxidation reaction of long-chain α-olefins and a preparation method thereof. The catalyst comprises an active component and a carrier, wherein the active component is CuO nanoparticles and the carrier is a CuO nanoparticle with a specific surface area of ​​100 m 2 / g~300m 2 / g porous Al2O3, wherein the carrier is one or more of α-Al2O3, β-Al2O3, and γ-Al2O3. The heterogeneous catalyst provided by the present invention can catalyze the epoxidation reaction of long-chain α-olefins with oxygen to produce high-carbon epoxides. The catalyst of the present invention has good catalytic activity, target product selectivity, and economic advantages, and the reaction conditions of the corresponding catalytic system are mild, making it very suitable for industrial applications.

The present application relates to an epoxidation catalyst, a preparation method and use thereof, the epoxidation catalyst comprising a carrier and an epoxidation active catalytic layer supported on the carrier; the epoxidation active catalytic layer comprises a transition metal layer; the carrier comprises a support material and a magnetic heat-conductive layer coated outside the support material; the magnetic heat-conductive layer contains a magnetic material and a heat-conductive ceramic material; the magnetic material comprises a magnetic particle inner core and a porous oxide shell coated outside the magnetic particle inner core. The preparation method of the epoxidation catalyst provided by the present application is simple, the single-batch production capacity is large, the preparation efficiency is relatively high, and the obtained epoxidation catalyst has good catalytic effect for olefin epoxidation reaction.

The present invention discloses an alumina-based catalyst, and its preparation method includes: (1) preparing an aluminum oxide matrix; (2) preparing a primary coated product; (3) preparing an iridium oxide-loaded product; (4) treating the iridium oxide-loaded product with an ethanol solution of γ-aminopropyltriethoxysilane and copper Meso-tetra(4-carboxyphenyl)porphyrin to obtain the alumina-based catalyst. The catalyst prepared by the method of the present invention has a good catalytic effect on the epoxidation reaction of olefins, greatly improves the conversion rate of olefins, makes the reaction more complete, and has a relatively high selectivity for the target product alkylene oxide and relatively few reaction by-products.

The embodiment of the invention discloses a preparation method of epoxidized olefin based on organic electrochemical synthesis, and is characterized in that the method comprises the following steps: adding an electrolyte containing corresponding anions into a closed pressurized electrolytic tank according to a reaction path selected by an epoxidation reaction of olefin; and performing an epoxidation reaction of olefin in the closed pressurized electrolytic tank under electro-catalysis so as to perform an epoxidation reaction with target selectivity and obtain epoxidized olefin with target yield. According to the embodiment of the invention, the epoxidation reaction under the electro-catalysis of the olefin is carried out in the closed pressurized environment, the loss caused by the volatilization of the olefin and the solvent is effectively reduced, the yield is improved, and the corresponding anions are added into the electrolytic tank for carrying out the epoxidation reaction according to the selected oxidation path of the olefin epoxidation; therefore, optimization of selectivity and yield of the epoxidation reaction of olefin is realized.

This invention provides a hierarchical porous TS-1 molecular sieve, its preparation method, and its applications, belonging to the field of catalysts. The method for preparing the hierarchical porous TS-1 molecular sieve involves directly adding a silanizing agent to a crystallization system to produce a hierarchical porous TS-1 molecular sieve with uniform particle size distribution and high crystallinity. This molecular sieve also features a large specific surface area and large pore volume, and exhibits high selective oxidation activity in macromolecular oxidation reactions. Specifically, this invention uses the synthesized hierarchical porous TS-1 molecular sieve to catalyze the epoxidation reaction of C4-C6 olefins. Results show that the olefin conversion rate is not less than 20%, and the effective utilization rate of hydrogen peroxide is not less than 80%, effectively solving the problems of hindered feedstock diffusion and easy pore blockage in C4-C6 olefin oxidation reactions, thereby improving its catalytic activity and stability.