117 results about "Keggin structure" patented technology

The invention discloses a method for preparing phosphotungstic heteropoly acid with a Keggin structure. The method comprises the following steps of: (1) contacting a tungstate solution and an inorganic acid solution; (2) transferring the solution to a high-pressure reaction kettle, and activating at high temperature under high pressure to obtain an active intermediate; (3) contacting the obtained substance and phosphoric acid to obtain a phosphotungstic acid solution; and (4) adding an inorganic salt precipitator into the phosphotungstic acid solution, precipitating phosphotungstic acid by salting-out and crystallization, filtering, purifying and drying to obtain the Keggin phosphotungstic heteropoly acid. By the method, a process flow is simple, the yield of the heteropoly acid is high, and the preparation cost is reduced obviously; high-concentration strong acid in the conventional method is not used in the preparation process, so that the corrosivity to equipment is reduced greatly; and an inflammable low-boiling point organic extractant is not used, and the safety of preparation is improved greatly.

The invention is a silicotungstic and phosphotungstic heteropoly acid load catalyst used for esterification reaction, which comprises the following components: Keggin structure silicotungstic acid H3SiW12O40.xH2O and phosphotungstic H3PW12O40.xH20, the content occupies 10 to 50 quality per centage of the amount of the catalyst; the carrier is H Beta zeolite. The invention adopts soaking method to prepare the solid silicotungstic and phosphotungstic heteropoly acid catalyst load on the H Beta zeolite, which can be used for catalyzing the esterification reaction of etic acid, isobutanol, isobutanol and ethanol, but also can be used for catalyzing esterification reaction of lactic acid and isobutanol to synthesis n-butyl acetate, isobutyl acetate, ethyl acetate and N-Butyl Lactate. The invention has the advantages of good stability, high activity and good selectivity, but also can used as inhomogeneous catalyst which is easy to be separated with reaction product and can use the prepared and formed catalyst powder in the continuous operating fixed bed reactor. The invention is used in the techinics of esterification reaction catalyzing rectifying.

The present invention relates to a composite catalyst for preparing sec-butyl acetate by direct esterification of ethyl ester and butylene, which takes heteropoly acid as the catalyst active component and porous carrier as the dispersant; the weight proportion of the heteropoly acid and the porous carrier is 0.01:1 to 10:1. The heteropoly acid is one with Keggin structure, which consists of phosphotungstic acid, silicotungstic acid, germanium tungstic acid, arsenowolframic acid, phosphomolybdate, germanomolybdate or arsenicomolybdate. The porous carrier comprises porous SiO2, Al2O3, SBA-15, MCM-41, white carbon black, porous SiC, corallite, andalusite, cordierite, meerschaum, Attapulgite or kaolin. The composite catalyst of the present invention solves the problem that the catalysis efficiency is low if the heteropoly acid is separated out from the reaction system.

This invention describes a process for preparing high-purity nanoscale polyalumina sols. This invention uses active aluminum hydroxide and industrial hydrochloric acid as raw materials, and adopts a two-stage reverse stripping process to produce a solution of polyaluminum chloride with an alkalinity higher than 50%, which is then increased to 70% or higher using high-purity calcium aluminate as the alkalizer. The process ensures complete stripping of the aluminum hydroxide raw material at normal atmosphere and a low temperature, thus obtaining a high-purity product. In addition, in the produced polyaluminum chloride sols the total content of nanoscale Al13 and Al30 having Keggin structure is higher than 70%, the alkalinity is 70-85% and the aluminum concentration is 10-19% (measured as Al2O3). The product is widely used as raw material for modern fine chemical binders, gluing agent for neutral paper manufacturing, intermediate or additive for modern pharmaceutical technology, coupling agent and catalyst for chemical production and flocculant for water treatment, and has potential applications in such emerging fields as inorganic nanocomposites and inorganic membrane materials.

The ester hydrolyzing method includes hydrolyzing ester in water to produce C1-C10 fatty acid or aromatic acid and C1-C4 fatty alcohol under the presence of ammonium salt of heteropoly acid as catalyst. The ammonium salt of heteropoly acid is obtained through the reaction between heteropoly acid in Keggin structure and inorganic ammonium salt or organic amine, the heteropoly acid is selected from phosphotungstic acid, silicotungstic acid, silicomolybdic acid and phosphomolybdic acid; the inorganic ammonium salt is selected from ammonium carbonate, ammonium nitrate, ammonium sulfate, ammonium phosphate and diammonium hydrochloride; and the organic amine is selected from fatty amine, alicyclic amine and arylamine. The said ester hydrolyzing method can obtain high conversion rate in relatively lower water/ester ratio and relatively short time, and the catalyst is cheap and easy to separate from the product.

The invention provides a preparation method of high-purity heteropolyacid with Keggin structure, which comprises the steps that an acid precipitant is added into heteropolyacid and/or the water solution of heteropolyacid salt so as to cause the heteropolyacid to precipitate out, and then the heteropolyacid is filtered and dried to obtain the high-purity heteropolyacid with the Keggin structure. The acid precipitant is mineral acid, more specifically, is selected from the mixture of hydrochloric acid and sulphuric acid or nitric acid, or hydrochloric acid, sulphuric acid and nitric acid with any volume ratio. The molar concentration of the acid precipitant in the reaction system is 0.1-8 mol/L. Compared with the prior art, the preparation method of the invention has simple process and high purity of products, does not use a great quantity of inflammable organic extractants when in production, and is applicable to being used as an acid catalyst.

The invention relates to the chemical field, in particular to a deep hydrodesulfurization solid-acid catalyst of gasoline and a preparation method thereof. Keggin-structure polyoxometallate (POM) is carried on a nano-sized ZSM-5 molecular sieve, and nickel nitrate is added to improve the catalytic performance of the catalyst. The invention is applicable to the modification of gasolines such as FCC gasoline, DCC gasoline, thermal cracking gasoline, coker gasoline and the like. The sulphur content in the gasoline treated by the catalyst is greatly reduced, and the catalyst has good low-temperature aromatization performance and is an ideal desulfurating, olefin-reducing and low-temperature aromatization catalyst.

A preparation of alkyl glycoside which uses solid supported heteropoly acid as catalyst, which pertains to field of preparation of alkyl glucoside. The invention use heteropoly acid solid supported by active carbon as catalyst, execute glycosidation with butanol and glucose, alcohol exchange with C8-C12 alcohol to prepare C8-C12 alkyl glucoside; solid support phosphotungstic acid or silicotungstic acid with a Keggin structure on active carbon to form strong acid catalyst; glycosidation of anhydrous glucose and butanol is carried out in presence of heteropoly acid to obtain n-butyrate glycoside, then alcohol exchange with C8-C12 long chain aliphatic alcohol, after extraction separation and vacuum distillation, C8-C12 alkyl glycoside is obtained. Advantages of the invention is that catalyst is high in activity and selectivity, and is reusable. The Preparation is simple, neutralization, albefaction and decolouration are eliminated. The obtained product is achroic or approximately achroic, transparent, no objectionable odor, and storage-stable.

The invention relates to a preparation method of a silicotungstic heteropoly acid loaded catalyst, and aims to mainly solve the problem of poor activity of silicotungstic heteropoly acid loaded catalysts in the prior art. The method of the invention includes the following steps of: a) steeping a molded SiO2 carrier in an alkaline solution with a concentration of 0.001-5 mol/L for 8-48 hours at a temperature of 10-100DEG C, and conducting filtration, washing, as well as drying for standby use; b) dissolving a Keggin structured silicotungstic heteropoly acid H3SiW12O40.x H2O in water or an organic solvent; c) mixing the SiO2 carrier treated by step a) with the silicotungstic heteropoly acid solution obtained in step b); and d) carrying out dynamic steeping on the liquid-solid mixture obtained in step c), then performing drying and roasting in an inert atmosphere, thus obtaining the silicotungstic heteropoly acid loaded catalyst. The technical scheme adopted by the method of the invention well solves the problem, and can be used in the industrial production of silicotungstic heteropoly acid loaded catalysts.

The invention relates to a polyoxometallate catalyst for preparing biodiesel. The catalyst is a polyoxometallate compound which has a Keggin structure or a Dawson structure. Biodiesel is catalytically prepared by the catalyst. The catalyst has high catalytic activity and repeatability and wide raw material applicability. The whole preparation process is free of waste water, so that the catalyst is green and environmental-friendly.

The invention provides a catalyst for constructing a heteropoly acid compound with a Keggin structure, peroxide and a titanium-silicon molecular sieve. The catalyst is characterized by being prepared from the following components in parts by mass: 1-40 parts of the heteropoly acid compound with the Keggin structure, 1-20 parts of peroxide and 98-40 parts of the titanium-silicon molecular sieve. A preparation method of the catalyst comprises the following steps: after preparing titanium silicon zeolite with an MIF (Migratory Inhibitory Factor) structure, introducing the heteropoly acid compound with the Keggin structure and the peroxide into the components; and washing, drying and roasting. The catalyst provided by the invention has high oxidation desulfurization catalytic activity, and the content of organic sulfur can be reduced to be lower than 10microg/g from 200microg/g; the catalyst has good recyclability; and the catalyst is an ideal oxidation desulfurization catalyst with excellent performance. The preparation method of the catalyst is simple, is easy to operate and is low in preparation cost.

The invention relates to the field of inorganic non-metallic material preparation, and particularly discloses polyoxometallate and a compound, a preparation method and application thereof. The molecular formula of polyoxometallate is (NH4)3PW11O39Sn, polyoxometallate has a Keggin structure, and the grain size is 10nm to 30nm. A catalyst, which is applied in the degradation of organic pollutant acid scarlet 3R, not only has excellent catalytic activity under visible light, but also has the advantages of simple separation and recyclability, and is an environment-friendly catalyst.

The invention discloses an immobilized cesium phosphotungstate catalyst. Cesium phosphotungstate is introduced in the synthesis process of a metal-organic skeletal material UiO-66 to make the mass ratio of the active component cesium phosphotungstate to the metal-organic skeletal material UiO-66 in the metal organic skeletal immobilized cesium phosphotungstate catalyst reach 0.2-0.65 and the specific surface area of the immobilized catalyst reach 794-1045m<2>/g. A preparation method adopting one-step in situ synthesis can effectively prevent loss of the active site cesium phosphotungstate, so the physical and chemical stability of the catalyst is improved; the Keggin structure, the strong acidity and the oxidation reduction property of cesium phosphotungstate are well kept, so the catalyst has wide application range; adsorption and diffusion of reaction substances on the catalyst are facilitated, so the catalysis efficiency of the catalyst is increased; and the preparation method has the advantages of simplicity, easy operation, easy filtration and separation of the catalyst from products, no corrosion, and no pollution to environment.

The invention relates to a method for preparing rare ginsenoside CK from protopanaxadiol ginsenoside through fermentation of microbacterium oxydans, in particular to a method for preparing 20-O-beta-D-glucopyranose-20-protopanaxadiol ginsenoside from protopanaxadiol ginsenoside Rb1, Rd and the like converted by utilizing fermentation of microbiological strains in a fully-automatic fermentation tank, belongs to the technical field of medicine, and comprises the steps: (1) fermentation cultivation of bacterial strains; conversion of raw materials Rb1, Rd and the like by utilizing fermented microorganisms and taking heteropolyacid HxYW12O40.nH2O with a Keggin structure as a catalyst, wherein Y is selected from P, Si, Fe or Zn, x is 3 or 4, and n is a positive integer ranging from 0 to 30; (3) preparative chromatographic separation and purification of conversion products, so as to finally obtain a compound with the chemical name being 20-O-beta-D-glucopyranose-20-protopanaxadiol ginsenoside.

The invention relates to a preparation method for organic-photic compound millimicron film material with remarkable photo-discoloration performance, its characteristic is that it combines the discoloration molecule self-assembly technology with sol gel course. The following technical steps are included: a. Heteropoly compound keggin structure of tungstosilicic acid, phosphotungstic acid, phosphomolybdic acid are saluted in absolute ethyl alcohol to form solution with a certain density; b. some methyl methacrylate is soluted in the mixture solution of toluene and chloroform then add some vinyltriethoxy silane into it, then it is heated to be 70deg.C in nitrogen and add benzoyl peroxide, stir it greatly until the reaction is complete; c. in the reaction course the heteropoly compound solution is added into; d, the copolymer generated is mixed with metallic alkoxide, benzoyl peroxide in aqueous thermostat and be added with alcohol, abtaining transparent sol solution; e. coat the transparent sol on substrate to be dried for 24 hours, finally the millimicron compound film is acquired.

The invention provides a process method for preparing ethyl tert-butyl ether. The process method comprises the following steps of: taking isobutene and ethanol as raw materials, and using a heteropoly acid/aluminum-based complex oxide catalyst, wherein the heteropoly acid/aluminum-based complex oxide catalyst takes a complex oxide as a carrier and takes heteropoly acid as an active component, the complex oxide is one or more of aluminum-based complex oxides in MgO-Al2O3, TiO2-Al2O3 and ZrO2-Al2O3, and the heteropoly acid is one or more of phosphotungstic acid, silicotungstic acid, arsenotungstic acid, germanotungtic acid, phosphomolybdic acid, silicomolybdic acid, arsenomolybdic acid, germanomolybdic acid and the like. According to the process method provided by the invention, the catalyst adopting the aluminum-based complex oxide to load the heteropoly acid is adopted, so that the shortcomings of inactivation of the catalyst and reduced conversion rate, which are caused by easiness in damaging the Keggin structure of the heteropoly acid of the heteropoly acid catalyst, easiness in loss of acid amount and difficulty in separation, can be overcome.

The invention provides an immobilized heteropoly acid ionic liquid catalyst for liquid phase Beckmann rearrangement reaction and a preparation method thereof. A carrier is graphene oxide (GO) powder prepared by a modified Hummers chemical method. The method comprises the following steps: firstly performing condensation reaction between GO and a silane coupling agent, then performing alkylation reaction with imidazole, successively sulfonating with alkyl sultone and finally performing disproportionated reaction through Keggin structure heteropolyacid. The immobilized heteropoly acid ionic liquid catalyst provided by the invention firstly utilizes GO as the carrier, and heteropoly acid ionic liquid with a sulfonic acid group is immobilized on the surface of the catalyst through a chemical grafting method. The preparation method provided by the invention has the benefits that raw materials are easy to obtain, the catalyst is simple to prepare, a solvent can be recycled after the catalyst is used, and almost no pollution is caused to the environment. The synthesized catalyst is applied to the liquid phase Beckmann rearrangement reaction; the catalyst is convenient for separation and recovery operation, and long in service life, so that the use cost is greatly reduced; therefore, the catalyst becomes a green chemical novel catalytic material with an application prospect.

The invention discloses a polyacid catalyst for catalyzing oriented conversion of lignocellulose and a preparation method thereof. The polyacid catalyst is a polyacid compound with a Keggin structure and can be adopted for catalyzing the lignocellulose to prepare glucose, xylose and oxalaldehyde. The catalyst disclosed by the invention is high in catalytic activity and repeatability and wide in material applicability, and in the whole preparation process, no waste water is generated, and the green and environment-friendly effects are achieved.

The present invention relates to one kind of polyoxometallate catalyst for preparing biodiesel oil, and the polyoxometallate is compound in Keggin structure or Dawson structure. The polyoxometallate catalyst is used in preparing biodiesel oil and has high catalytic activity, high repeatability and wide material adaptability. The preparation process is green and produces no waste water.

The process of synthesizing mesoporous TiO2 with phosphotungstic acid as template agent relates to process of synthesizing mesoporous molecular sieve and realizing material doping modification with solid acid template agent and belongs to the field of inorganic porous material synthesizing technology. The mesoporous TiO2 is synthesized through dissolving tetrabutyl titanate in anhydrous alcohol and adding water solution of phosphotungstic acid via stirring; taking the mixture, rotation evaporating and washing; vacuum drying and roasting at 500deg.C for 3 hr. The present invention utilizes the Keggin structure of phosphotungstic acid to form hydrogen bond between the water molecule and phosphotungstic acid molecule and to serve as template agent so as to synthesize the mesoporous material and modify TiO2 simultaneously. The mesoporous TiO2 has great specific surface area, homogeneous pore size, ordered structure and excellent stability.

The invention discloses a novel absorbing material and a preparation method of the novel absorbing material and relates to an absorbing material obtained by modifying clay mineral through a pillar. One purpose of the invention is to provide an absorbing material applied to water treatment; the absorbing material comprises pillar clay obtained by modifying a clay mineral suspension liquid containing a smectite structure through a pillaring agent pillar; the pillaring agent is aluminum 30 reinforced polycation; the clay mineral comprises one or two out of montmorillonite and bentonite; the pillaring agent is preferably selected from the aluminum 30 reinforced polycation containing double keggin structure. The other purpose of the invention is to provide a preparation method for preparing the absorbing material by modifying the clay mineral through an aluminum 30 reinforced polycation pillar.