30 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 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.

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 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 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 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 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.

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.

The application belongs to the technical field of catalyst forming, and particularly relates to a method for secondary forming of titanium silicalite TS-1 waste powder, which comprises the following steps: S1, grinding titanium silicalite TS-1 waste powder to 60 mesh or less, adding a pore forming agent and mixing, and then adding TS-1 mother liquor and kneading to obtain a cohesive block; S2, extruding the cohesive block into a wet base strip to obtain a wet base strip-shaped catalyst; S3, drying the wet base strip-shaped catalyst to obtain a dry base strip-shaped catalyst; and S4, calcining the dry base strip-shaped catalyst to obtain an extruded strip-shaped catalyst. The TS-1 catalyst prepared by the application is used for various oxidation reactions such as olefin epoxidation, aromatic hydroxylation, ketone ammoxidation, alkane selective oxidation, oxidative desulfurization and alcohol oxidation, realizes secondary utilization of the waste powder and the TS-1 mother liquor, reduces the catalyst preparation cost, reduces environmental pollution, and the mechanical strength of the secondary extruded strip-shaped TS-1 catalyst is 1.5 times that of the prior art.

The invention discloses a preparation method and application of a surface-hydrophobized bismuth molybdate catalyst, and belongs to the technical field of olefin epoxidation. According to the method, a one-pot hydrothermal method is adopted, in the synthesis process of bismuth molybdate, organic acid and organic amine are synchronously added to serve as composite hydrophobic modifiers, and a stable hydrophobic layer is constructed on the surface of the bismuth molybdate under the premise that the crystal structure of the bismuth molybdate is kept unchanged through the synergistic coordination and hydrogen bond assembly effect between the organic acid and the organic amine. The water contact angle of the hydrophobic bismuth molybdate catalyst can be adjusted between 45 degrees and 105 degrees. The method is simple in process, and complicated post-treatment steps are avoided. The prepared catalyst is used in an olefin epoxidation process, can significantly improve the mass transfer efficiency among oil-water-solid phases, and shows high epoxidation conversion rate and selectivity to olefin under mild conditions.

The invention discloses a titanium silicalite molecular sieve and a rolling ball forming preparation method thereof. The method comprises the following steps: S1, crystallizing the titanium silicalite molecular sieve to be subjected to rolling ball forming, and performing spray drying and roasting on slurry to obtain molecular sieve powder for rolling balls; s2, the molecular sieve powder prepared in the step S1, a binding agent, water and a lubricating agent are subjected to ball rolling primary forming, and primary formed wet balls are obtained; s3, mixing the primarily-formed wet pellets prepared in the step S2 with the molecular sieve powder prepared in the step S1, a binder, water and a lubricant, and carrying out ball rolling secondary forming to obtain secondarily-formed wet pellets; and S4, drying and roasting the secondary formed wet pellets prepared in the step S3 to obtain the final titanium silicalite molecular sieve subjected to ball forming. The step-by-step forming is combined with the use of the lubricant, the uniformity and size control of the ball are optimized, cracking or deformation is avoided, and the ball prepared by the method is high in strength and uniform in particle size, and has good application in olefin epoxidation.

The application of binaphthyl Salen cobalt molecular catalyst modified BiVO4 photoanode belongs to the field of photoelectrocatalysis technology and organic synthesis cross. BiOI film is deposited on FTO conductive glass by electrochemical deposition method, and then is converted into BiVO4 photoanode substrate by calcination; 3-hydroxy substituted binaphthyl Salen cobalt molecular catalyst CoL is synthesized; CoL is loaded on the surface of BiVO4 by cyclic voltammetry electrodeposition to obtain a hybrid photoanode. The photoanode is applied to the photoelectrocatalytic olefin epoxidation reaction, water is used as oxygen source, and acetone-water is used as electrolyte. The strong interface coupling between the catalyst and BiVO4 is strengthened by the electrodeposition of the molecular catalyst strategy, and the interface charge transport efficiency, reaction conversion rate and selectivity are improved. The conversion rate of styrene reaches 99%, the selectivity of epoxide reaches more than 90%, and the stability is excellent. The application provides a new way for green and efficient synthesis of epoxide, and has wide application prospect.

This invention discloses a fully crystalline Ti-MWW molecular sieve catalyst, its preparation method, and its applications. The UV-Raman spectrum of the fully crystalline Ti-MWW molecular sieve catalyst is at 343±4 cm⁻¹. ‑1 484±4cm ‑1 699±4cm ‑1 and 1097±4cm ‑1 A spectral peak appears at 699±4cm. ‑1 The intensity of the spectral peak is 343±4 cm⁻¹. ‑1 The peak intensity is 0.5 to 10 times that of the spectral peak, 1097 ± 4 cm⁻¹ ‑1 The intensity of the spectral peak is 343±4 cm⁻¹. ‑1 The spectral peak intensity is 0.5 to 10 times that of the standard. The Ti-MWW molecular sieve catalyst, when used in olefin epoxidation reactions, exhibits high olefin conversion, high epoxide selectivity, and good catalytic stability.

According to the preparation method of the titanium silicalite molecular sieve, free radicals in a solution are excited through a generated cavitation effect, so that the influence of non-framework titanium on olefin epoxidation in the synthesis process of the molecular sieve is weakened, the size of the molecular sieve is reduced, and Ti element distribution is improved; the use of a solvent and a surfactant in the preparation process of the titanium silicalite molecular sieve can be directly avoided, so that the environment is further protected, and the synthesis time of the titanium silicalite molecular sieve can be effectively shortened by adopting a continuous synthesis operation flow; and non-framework titanium in the titanium silicalite molecular sieve can be eliminated, so that the olefin epoxidation performance of the molecular sieve is effectively improved.

The application discloses a kind of micro mesoporous composite titanium-containing silicate molecular sieve and its preparation method and application, its characteristics are that the micro mesoporous composite molecular sieve contains titanium, silicon, boron, oxygen and other framework elements, its composition is expressed as B x Ti y SiO z , micro mesoporous molecular sieve is used with double imidazole group polycarbon chain quaternary ammonium salt as organic template agent, is obtained under high temperature and high pressure by hydrothermal treatment, the molecular sieve is used for catalyzing olefin epoxidation reaction and aldehyde ketone compound ammoxidation reaction respectively corresponding epoxide and oxime compound with high product yield.The application compared with prior art has mesostructure and open pore structure with mesopore, in olefin epoxidation and aldehyde ketone ammoxidation reaction, show the characteristics of mild reaction condition, high activity and less byproduct, meet the requirement of green production "atomic economy" of oxygen (nitrogen) chemical, fit the concept of "green chemistry", further widen the research and application field of selection catalytic reaction.

The application discloses a titanium-silicon catalyst for catalyzing an olefin epoxidation reaction and a preparation method thereof, and the preparation method comprises the following steps: mixing Ti-Beta molecular sieve, water, tetrapropylammonium hydroxide, n-butyl titanate and modified porous carbon, and then performing a crystallization reaction; collecting insoluble substances and performing calcination treatment, so as to obtain the titanium-silicon catalyst for catalyzing the olefin epoxidation reaction. In the application, the structure directing agent tetrapropylammonium hydroxide and the n-butyl titanate are introduced on the basis of the Ti-Beta molecular sieve, and the modified porous carbon is further introduced when the n-butyl titanate is treated. The carbon component is removed in high-temperature calcination, the metal component is combined with the molecular sieve in situ, the pore size of the composite structure is more abundant, and the Ti active center is more easily exposed. The titanium-silicon catalyst constructed in the application has good catalytic activity and selectivity for the olefin epoxidation reaction, and has good regeneration.

The invention belongs to the technical field of catalysts, and discloses an alpha-alumina carrier, a preparation method thereof, a silver catalyst for olefin epoxidation and an olefin epoxidation method. The preparation method comprises the following steps: (1) mixing alumina trihydrate, pseudo-boehmite, modified carbon nanotubes, an optional alkaline earth metal compound and an optional fluoride-containing compound to obtain a mixture; and (2) kneading the mixture and the binder aqueous solution, and then carrying out compression molding, drying and roasting to obtain the alpha-alumina carrier. The modified carbon nanotubes are added in the preparation process of the carrier, so that the specific surface area, the pore size, the water absorption rate and the permeability of the carrier can be optimized at the same time. The carrier disclosed by the invention can be used for olefin epoxidation reaction, in particular to a carrier of a catalyst for preparing ethylene oxide by ethylene epoxidation.

This invention discloses an olefin epoxidized titanium silicate catalyst, its preparation method, and its applications. The UV-Raman spectrum of the olefin epoxidized titanium silicate catalyst of this invention is at 364±6 cm⁻¹. ‑1 500±6cm ‑1 and 1102±6cm ‑1 A spectral peak appears at 1102±6 cm⁻¹. ‑1 The intensity of the spectral peak is 364±6 cm⁻¹. ‑1 The peak intensity is 1 to 10 times that of the catalyst in this invention. The catalyst used in the olefin epoxidation reaction exhibits high olefin conversion, high epoxide selectivity, and good catalytic stability.

The present application relates to the field of catalysis, discloses a catalyst, a preparation method thereof and a method for hydrofining of recovered solvent of olefin epoxidation reaction, the catalyst comprises a carrier and an active component supported on the carrier, the active component is Ni and Cu; wherein, the molar ratio of Ni and Cu in the catalyst is 0.5-5:1. The recovered solvent of olefin epoxidation reaction is hydrofined by using the catalyst, and acetaldehyde, hydrogen peroxide in the recovered solvent can be basically removed, and part of dimethoxyethane can be removed, so that the purpose of refining the recovered solvent is achieved. And more than 15% of steam energy consumption can be saved per year. In addition, the circulation and accumulation of dimethoxyethane in the solvent system of the device is avoided, the amount of fresh methanol supplemented for replacing dimethoxyethane is greatly reduced, and more than 50% of the original methanol consumption can be saved per year.

The application discloses an epoxidation catalyst and a liquid-phase preparation method. Titanium is grafted into the skeleton of a carrier SiO2 by adopting a liquid-phase static grafting method. The introduction of rare earth elements improves the stability of the carrier structure and active components, strengthens the directional grafting of titanium and the distribution of active sites, improves the activity and stability of the catalyst in olefin epoxidation, and avoids the corrosion of equipment and the poisoning of copper-based catalysts in the POSM process in the whole process without introducing chlorine elements.