195 results about "Silicotungstic acid" patented technology

There is provided an aqueous dispersion for CMP with an excellent balance between chemical etching and mechanical polishing performance. The aqueous dispersion for CMP of the invention is characterized by comprising an abrasive, water and a heteropolyacid. Another aqueous dispersion for CMP according to the invention is characterized by comprising an abrasive, water, a heteropolyacid and an organic acid. Yet another aqueous dispersion for CMP according to the invention is characterized by comprising colloidal silica with a primary particle size of 5-100 nm, water and a heteropolyacid. Preferred for the heteropolyacid is at least one type selected from among silicomolybdic acid, phosphorotungstic acid, silicotungstic acid, phosphoromolybdic acid and silicotungstomolybdic acid. Preferred for the organic acid is at least one selected from among oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid, malic acid, tartaric acid and citric acid.

The invention discloses a preparation method of improved 4,4-dichlorodiphenylsulfone. The method comprises steps that: (1) Al2Cl3 is adopted as a catalyst; chlorobenzene, thionyl chloride are adopted as reaction materials; the materials are subject to a Friedel-Crafts reaction; a mother liquor obtained after the reaction is hydrolyzed; the hydrolyzed mother liquor is refluxed for 45 to 60min under a temperature of 95 to 100 DEG C; after refluxing, the mother liquor is cooled to below 20 DEG C, such that the liquor is divided into an organic phase and a water phase; the organic phase is processed through reduced-pressure distillation and centrifugal washing until the organic phase turns neutral, and the organic phase is preserved as a product M for later use, wherein a main component in the product M is 4,4-dichlorodiphenylsulfone; (2) the product M and an oxidizing agent of hydrogen peroxide are adopted as raw materials, and 1,2-dichloropropane is adopted as an organic solvent; an oxidizing reaction is carried out upon the main component 4,4-dichlorodiphenylsulfone in the product M under the effect of a composite catalyst, such that a 4,4-dichlorodiphenylsulfone crude product is synthesized, wherein the composite catalyst is phosphotungstic acid or silicotungstic acid loaded on active carbon. Therefore, the method provided by the invention has advantages of high yield and good product quality. With the method, wastewater can be circulated and reused.

The invention discloses a mesoporous WO[3-x] visible-light-driven photocatalyst with oxygen vacancy and a preparation method thereof. The method comprises the following steps: calcinating at a controlled temperature of 350-600 DEG C in air so as to obtain a mesoporous silica molecular sieve KIT-6 loaded with tungsten trioxide by taking mesoporous silica molecular sieve KIT-6 as a hard template and a silicotungstic acid or phosphotungstic acid hydrate as a tungsten trioxide precursor; then calcinating at a controlled temperature of 450-550 DEG C so as to obtain a mesoporous silica molecular sieve KIT-6 provided with oxygen vacancy and loaded with tungsten trioxide by utilizing H2 as a reducing agent; and finally, removing the mesoporous silica molecular sieve KIT-6 by use of a 10wt% HF aqueous solution, thereby obtaining the mesoporous WO[3-x] visible-light-driven photocatalyst with oxygen vacancy and relatively large specific surface area and pore diameter. The mesoporous WO[3-x] visible-light-driven photocatalyst with oxygen vacancy is capable of effectively utilizing lights to rapidly catalyze CO2 so as to generate methane, and is high in catalysis efficiency, simple in preparation process and needed equipment, environmentally friendly in preparation process and free from pollution.

There is provided an aqueous dispersion for CMP with an excellent balance between chemical etching and mechanical polishing performance. The aqueous dispersion for CMP of the invention is characterized by comprising an abrasive, water and a heteropolyacid. Another aqueous dispersion for CMP according to the invention is characterized by comprising an abrasive, water, a heteropolyacid and an organic acid. Yet another aqueous dispersion for CMP according to the invention is characterized by comprising colloidal silica with a primary particle size of 5-100 nm, water and a heteropolyacid. Preferred for the heteropolyacid is at least one type selected from among silicomolybdic acid, phosphorotungstic acid, silicotungstic acid, phosphoromolybdic acid and silicotungstomolybdic acid. Preferred for the organic acid is at least one selected from among oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid, malic acid, tartaric acid and citric acid.

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.

The invention discloses a fluorination catalyst, and a preparation method and a use thereof, and belongs to the field of chemical synthesis. The precursor of the catalyst is formed by blending 40-95mass% of a trivalent chromium compound with 5-60mass% of tungstate, wherein the trivalent chromium compound can be chromic oxide or chromium hydroxide, and the tungstate can be zinc tungstate, nickel tungstate, magnesium tungstate, aluminum tungstate, silicotungstic acid, ammonium tungstate, ammonium paratungstate or ammonium metatungstate. The fluorination catalyst has the advantages of high use temperature, high catalysis activity and long service life, and can be mainly used in reactions for preparing fluorinated alkenes through gas phase catalysis of fluorination of alkenyl halides at a high temperature.

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 relates to a metal-organic framework crystalline material with a nano-cage structure, in particular to a polyoxometalate (POM)-based metal-organic frameworks (POMOFs) crystalline material with a nano-cage structure and a preparation method and application thereof and aims to solve the problems in the prior art that a POMOFs crystalline material with a nano-cage structure is high in synthesis difficulty and poor in rhodamine B organic dye degradation effect. The POMOFs crystalline material has the chemical formula of Ag10(tta)4(H2O)4(SiW<IV>10W<V>2O40), the tetragonal system, and the space groups of I-4m2, alpha=90, beta=90, gamma=90 and Z=2. The preparation method comprises the following steps: dissolving silicotungstic acid, silver nitrate, tetrazole and a mineralizer in distilled water; regulating the pH value; carrying out a reaction for 3 days at 160 DEG C. The POMOFs crystalline material with the nano-cage structure can be obtained.

The present invention relates to a ZnO@ZIF-8 core-shell structure compound. The synthesis method of the compound comprises the following steps: adding zinc acetate and silicotungstic acid to a reactor; stirring the mixture for 0.5-1h at room temperature; reacting for three days at the temperature of 120 DEG C to obtain a white precipitate, namely ZnO; then adding the obtained ZnO and 2-methylimidazole to a reactor filled with a mixed solution of water and DMF; performing ultrasonic processing for 10min; and reacting for 24h at the temperature of 75 DEG C to obtain a white precipitate, namely a target product. The ZnO@ZIF-8 core-shell structure compound material can be used as a photocatalyst to efficiently degrade the organic dyestuff.

The present invention is process of synthesizing guaiacol, and relates to the application of catalyst in catalytically synthesizing guaiacol through the solid phase alkylation reaction between catechol and methanol. The catalyst has active component of ammonium metatungstate, sodium tungstate, ammonium molybdenum, ammonium biphosphate, ammonium phosphate, ammonium chromate or silicotungstic acid; and carrier of active carbon, SiO2, ZnO, Al2O3, TiO2, BaCO3 or CaO; and active component supporting amount of 2.1-30.2 wt%. The process of synthesizing guaiacol has catalytic reaction temperature of 533-573 K, the molar ratio between catechol and methanol of 1 / 7-1 / 2.5, and catalyst amount of 0.84-2.8 weight portions. During the process, the mixed solution of catechol and methanol is fed to the pre-heater in the flow rate of 0.3-2ml / hr, gasified and reacted catalytically at the temperature of 533-573 K.

The invention belongs to the photoelectric and chemical technical field of nano titanium dioxides, in particular to an in-situ preparation method for a silicon-tungsten and TiO2 codoped nanotube film. The invention comprises the following steps: a pretreated metal Ti piece serves as an anode, a graphite piece serves as a cathode, and an HF solution serves as an electrolyte; silicotungstic acid is added in the electrolyte; the anode of a DC stabilized voltage supply is subjected to oxidation; and heat treatment is performed in a pipe furnace, thereby, obtaining the silicon-tungsten and TiO2 codoped nanotube film; the visible light photocurrent of the electrode of the Si-W-TiO2 nanotube thin film electrode is proved to be about 2.6 times of that of the TiO2 nanotube thin film electrode through experiment; and the energy conversion efficiency of a dye sensitized solar cell assembled by the thin film electrode is higher than that of the dye sensitized solar cell made of pure TiO2 nanotube.

The invention discloses a hydrocracking catalyst and a preparation method thereof. In the catalyst, the acidic component is a silicotungstate, the hydrogenation metal component is nickel, and the carrier is silicon oxide. The catalyst is prepared by: adding a nickel salt and an alkali metal salt respectively into an aqueous solution containing organic acid I to obtain a solution A, adding a silicon source into a solution containing organic acid II to obtain a solution B, then mixing the solution A with the solution B, adding a silicotungstic acid aqueous solution, conducting stirring to evaporate the solution, and carrying out drying and roasting, thus obtaining the catalyst. The heteropolyacid used by the method is silicotungstic acid, and two organic acids are used cooperatively to reach a mutual promotion effect, so that the metal components and the acidic component are dispersed more evenly, the hydrogenation activity and the acid function are matched better, and also the catalyst can have larger specific surface area, pore size and pore volume. Thus, the catalyst has better catalytic performance. The catalyst prepared by the invention is especially suitable for a hydrocracking reaction of long chain alkane.

The invention discloses an energy-absorbing foam aluminum material for manufacturing a vehicle bumper. The material is characterized by being prepared by the following components in parts by weight: 100 parts of aluminum powder, 5 parts of tungstate, 5 parts of silicon carbide, 2 parts of iron ore powder, 1 part of silicotungstic acid, 0.5 part of magnesium oxide, and 0.5 part of modified foaming agent. The material is simple in preparation method, excellent in product effect, low in cost of the foaming agent and economical and effective, reduces traditional preparation steps, and reduces the production cost; and the porosity of foam aluminum is increased through dual functions of thickening and foaming of the foaming agent.

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 discloses a multi-acid-based microporous crystalline material and a preparation method thereof, and relates to the technical field of multi-acid-based microporous crystalline materials.The multi-acid-based microporous crystalline material has a chemical formula of Co2(bpy)(bpp)(bip)](H2O)3][SiW12O40]. The preparation method of the multi-acid-based microporous crystalline material comprises the following steps of 1, preparing reaction liquid with a pH value being 3 to 5; dissolving silicotungstic acid, metal cobalt salt and 3,5-bis(4-pyridyl)pyridine into distilled water to obtain reaction solution; then, regulating a pH value of the reaction liquid to be 3 to 5 to obtain the reaction liquid with the pH value being 3 to 5; 2, preparing the multi-acid-based microporous crystalline material with a three-dimensional metal-three-ligand nanometer pore passage structure; adding the reaction liquid with the pH value being 3 to 5 into a polytetrafluoroethylene reaction kettle; then, performing reaction at 160 DEG C for 4 days; lowering the temperature of the reaction liquid to room temperature; performing suction filtration on the reaction liquid to obtain reddish brown blocky polyhedron crystals. The multi-acid-based microporous crystalline material and the preparation method solve the problems of relatively fixed charges, coordination modes and steric configuration of single ligands of the conventional method for preparing a multi-acid-based microporous crystalline hybrid material.

The invention discloses a polysulfo-functionalized heteropolyacid ionic hybrid with multiple heteropolyacid negative ions as well as a preparation method and an application thereof. Two ionic hybrids with novel structures are built by taking aliphatic polyamine, 1,4-butanesultone, phosphotungstic acid and silicotungstic acid as starting materials and carrying out two steps of atomic economic reaction through quaternization and acidification. Positive ions of the ionic hybrid comprise four or three bissulfo-functionalized long-chain quaternary ammonium positive ions; negative ions matched with the positive ions comprise three Keggin configuration silicotungstic acid negative ions or two Keggin configuration phosphotungstic acid negative ions; the prepared ionic hybrid can be used for preparing cyclohexyl carboxylate. The ionic hybrid has high acid strength and high acid content; the ionic hybrid also shows high amphipathy, so the reaction between substrate cyclohexene and organic carboxylic acid is facilitated; the ionic hybrid has the characteristics of atom economy, mild reaction condition, no backflow water diversion, high separation probability of products and high purity.

The invention discloses a catalyst for preparing 1,3-propanediol through glycerine hydrogenolysis. According to the catalyst, alumina serves as a carrier, cobalt metal serves as an active ingredient, and adjuvants comprise silicotungstic acid, phosphotungstic acid, phosphomolybdic acid and the like, wherein the content of the active ingredient is 30% the mass of the carrier, and the content of the adjuvants is 5% the mass of the catalyst. The catalyst has the advantages of good catalytic activity, high 1,3-propanediol yield and the like, and can achieve high-selectivity glycerine-hydrogenolysis preparation of 1,3-propanediol at the reaction temperature of 150-300 DEG C and the hydrogen gas pressure of 1-10MPa. Raw materials for preparing the catalyst are rich and cheap, the process is simple, and the catalyst is reusable.

The invention relates to an ionic liquid-functionalized snowman-shaped anisotropic composite material and a preparation method and application thereof. The preparation method comprises the steps that Janus snowman-shaped composite particles are prepared and then modified with ionic liquid, and imidazolinyl-modified Janus snowman-shaped composite particles are prepared; chlorobutane is added to obtain Cl-based ionic liquid-functionalized Janus snowman-shaped composite particles, and anion exchange is performed on the Cl-based ionic liquid-functionalized Janus snowman-shaped composite particles and multiple inorganic salts such as KPF6 and silicotungstic acid or phosphomolybdic acid and the like to prepare the PF6-based or silicotungstic acid-based or phosphomolybdic acid-based ionic liquid-functionalized Janus snowman-shaped composite particles. According to the material, not only is the morphology partitioned, but also the surface chemical property is partitioned, the polystyrene side is oleophylic, the silicon dioxide side is adjustable, and when the silicon dioxide side uses hydrophilic anions, the characteristics obtained when a general Janus material is used for stabling Pickering emulsion are achieved.

The invention discloses a process for preparing acrylic aldehyde by using selective glycerol dehydration and a preparation method of a catalyst thereof. Heteropolyacid / a carrier is disclosed in the expression of the catalyst, wherein the heteropolyacid is one of silicotungstic acid, phosphotungstic acid and phosphomolybdic acid, and the carrier is one of activated aluminium oxide, kieselguhr, activated carbon, rutile type titanium dioxide and kaoline. The catalyst is prepared by using a constant-pore volume dipping method. When the catalyst is used in a fixed-bed miniature reaction device, the transformation rate of glycerol is 13.5%-80.6%, and the selectivity of the acrylic aldehyde is 49.0%-90.5%. When used for carrying out the process for preparing acrylic aldehyde by using glycerol dehydration, the catalyst has the advantages of high catalyst activity, high reaction speed, high selectivity for the acrylic aldehyde and the like, and the main byproduct is hydroxyl acetone.

The invention discloses a method for preparing bisphenol F. The method is characterized in that phenol and formaldehyde serving as raw materials and a solid acid catalyst serving as a catalyst are used to prepare the target product bisphenol F, wherein the solid acid catalyst is prepared from heteropoly acid modified clay, and the mass dosing ratio of the catalyst to formaldehyde is (0.01-0.6):1; and the heteropoly acid is one or more of phosphotungstic acid, phosphomolybdic acid, silicotungstic acid, silicomolybdic acid and the like, wherein the clay is one or more of bentonite, kaoline, montmorillonoid, metakaolin, diatomaceous earth and the like. The method has the prominent advantages that the yield of the product bisphenol F is up to 93 percent, the selection to bisphenol F is 96 percent, the catalyst is friendly to environment, the preparation process is simple, the production cycle is short, the catalyst activity and catalytic selection are high, separation and reclamation are easy, recycling is available, and industrialization is facilitated.

The invention relates to a urine detection reagent in the medical examination field, in particular to a detection reagent box for sulfydryl compounds in urine and a preparation method and application. The detection reagent box for sulfydryl compounds in urine comprises a detection reagent, a contrast reagent and a color developing reagent, wherein the detection reagent is an aqueous solution containing a mercurous ionic compound and trichloroacetic acid, the contrast reagent is an aqueous solution containing a mercury ionic compound, a mercurous ionic compound and trichloroacetic acid, and the color developing reagent is a buffering solution containing phosphotungstic acid, silicotungstic acid and a lithium ion compound. The detection reagent box for sulfydryl compounds in urine can be used for screening and auxiliary diagnosis of cervical cancer. Compared with the prior art, the technical scheme is simple in technology and high in stability, the false positive rate and the false negative rate are low according to the detection result, and the detection reagent box for sulfydryl compounds in urine is suitable for screening and auxiliary diagnosis of cervical cancer.

The invention discloses a full two-dimensional ternary compound g-C3N4 / MoS2 / SnS2 visible light response photo-catalyst and a preparation method. The preparation method comprises the following steps: dissolving sodium molybdate hydrate, thioacetamide and silicotungstic acid hydrate in deionized water to obtain a MoS2 nano-sheet; dissolving MoS2 in deionized water, and adding tin chloride hydrate and citric acid to obtain a MoS2 / SnS2 composite nano-sheet; heating urea and dissolving a powder and performing ultrasonic treatment, and performing peeling-off on the block to obtain a flaky g-C3N4; and compounding the MoS2 / SnS2 composite nano-sheet with the flaky g-C3N4 to obtain a nano-sheet of a ternary compound g-C3N4 / MoS2 / SnS2. The three units in the compound prepared by the method are in surface-surface contact and effectively compounded, and a staggered energy level structure is shown, so that absorption of visible light is increased, separation of electron-hole pairs is promoted, photo-catalytic efficiency is improved, and thereby the compound is expected to be widely used in the field of photo-catalytic degradation of organic matters, and has relatively good development prospects.

The invention relates to a method for producing glyoxylic acid by a glyoxal oxide water solution. The glyoxylic acid is produced through adopting heteropoly acid catalysts including nano TiO2 and nanoSiO2 cladded phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, silicomolybdic acid and the like, and cooperating two oxidants including air and nitric acid with the glyoxal oxide watersolution. According to the technical scheme, the method comprises three parts including preparation of the cladded heteropoly acid catalysts, production of the glyoxylic acid and post-treatment of areaction solution; quality indexes of a glyoxylic acid product are as follows: 50 percent to 51 percent of the glyoxylic acid, 0.4 percent to 0.7 percent of oxalic acid, 0.1 percent to 0.2 percent ofglyoxal, 0 to 0.01 percent of heavy metal, 0 to 0.1 percent of ignition residues, 82 percent to 87 percent of glyoxylic acid yield and 10 percent to 15 percent of oxalic acid yield. By adopting the method provided by the invention, the problems in the prior art that the corrosion on production requirement is serious, the consumption amount of the nitric acid is great and the glyoxylic acid selectivity is not good are solved.

The invention discloses a catalyst for selectively synthesizing 4-methyl-2,6-di-tert-butylphenol and application of the catalyst. The catalyst is prepared from a molecular sieve as a carrier modifiedby any one of ammonium phosphate, ammonium hydrogen phosphate and ammonium dihydrogen phosphate, and an active component A and an active component B carried by the carrier, wherein the molecular sieveis an Hbeta molecular sieve, H-mordenite, an HY molecular sieve, an USY (Ultra-Stable Y Zeolit) molecular sieve, an REY molecular sieve or a SAPO-5 (Silicoaluminophosphate) molecular sieve; the active component A is Co, Cu, Ni or Fe; the active component B is at least one of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, silicomolybdic acid and sodium tungstate; by the carrier,the carrying amount of the active component A is 2-5%, and the carrying amount of the active component B is 2-10%. The catalyst disclosed by the invention is applied to p-methylphenol and isobutene ortertiary butanol to produce 4-methyl-2,6-ditertiary butyl phenol, and has the advantages of low catalyst cost, high raw material conversion rate, good product selectivity, long catalyst service life,simple use process and the like.

This invention is dimethyl biphenyl methane synthetic catalyzing technique. It uses methylbenzene and formaldehyde as the raw materials, and under the function of solid acid catalyst to process condensation reaction. The weight ratio of methylbenzene and formaldehyde is 2 / 1-1 / 5, the reaction condition is: in the temperature of 100-200deg.C, the reaction time is 1-8 hours to get dim ethyl biphenyl methane. The catalysts comprises:HX molecular sieve, HY molecular sieve, HZSM-5 molecular sieve, H beta molecular sieve, mordenite, phosphatotungstic acid, molybdophosphoric acid, silicotungstic acid and loaded phosphatotungstic acid, molybdophosphoric acid, silicotungstic acid. This invention has simple reaction technique and little environmental pollution.

The invention relates to a preparation method of a silicotungstic acid / silicon dioxide polyvinyl alcohol proton exchange membrane, belonging to the field of battery electrolyte materials. The preparation method comprises the following steps of: firstly solving the polyvinyl alcohol in deionized water to prepare a macromolecular solution, adding silicon compounds and sodium tungstate to the prepared solution, heating and mixing to form a solution, pouring the solution on a polytetrafluoroethylene glass plate and drying to form a membrane, and then obtaining the required silicotungstic acid / silicon dioxide polyvinyl alcohol proton exchange membrane. The prepared proton exchange membrane has great proton conductivity and low methanol permeability and is convenient for the large-scale production.

The invention discloses an organic heteropoly hybrid catalyst for an esterification reaction. The organic components comprise polyvinyl pyrrolidone, methyl-pyrrolidone and caprolactam. The heteropoly acid is 12-phosphotungstic acid, 12-phosphomolybdic acid and 12-silicotungstic acid. The preparation method comprises the step that the organic components and the heteropoly acids are subjected to protonation to obtain the organic heteropoly hybrid catalyst. The invention has the advantages that the preparation process of the catalyst is simple and practicable; and the obtained catalyst is suitable for the esterification reaction of many kinds of carboxylic acids and alcohol, and has the characteristics of high catalytic activity and selectivity, convenient recycling, and stable reutilization performance, thereby being an environment-friendly novel solid acid catalyst.

A carried silicotungstic acid as catalyst used for preparing tetrahydrofuran from 1,4-butanediol through cyclizing and dewatering is prepared through dissolving silicotungstic acid in distilled water, isometrically immersing the carrier (kaolin or diatomite) in it, and calcining while stirring every 20-40 min.

The invention discloses low-temperature-resistant lubricating oil and a preparation method thereof. The lubricating oil is prepared from components in parts by weight as follows: base oil, nano tin powder, 1-phenyl cyclopentanecarboxylic acid, nano vanadium hydroxide, silicotungstic acid, calcium chloride, bis(cyclopentadiene)hafnium dichloride, sulfated castor oil, calcium gluconate, sodium dodecyl benzene sulfonate, a dandelion extracting solution, barium dinonyl naphthalene sulfonate, glycolic acid, ethoxy modified trisiloxane, lauryl alcohol phosphate acid ester, an antioxidant 1035 and glycerin, wherein the base oil is prepared from poly-alpha-olefin, castor oil and polyethylene glycol in the weight ratio being 5:2:4. The prepared lubricating oil has the lower pour point, smaller wear spots and the maximum non-seizure load, shows good low-temperature resistance, wear resistance and lubricating effect, is applicable to low-temperature complex environments and can effectively prolong the service life of use equipment.