20 results about "TETRAETHYLAMMONIUM HYDROXIDE" patented technology

The application relates to the technical field of Beta molecular sieve preparation, and discloses a method for rapidly preparing nano Beta molecular sieve by using a microwave synthesis method, which comprises the following steps: selecting appropriate silicon sources (such as silicon dioxide, white carbon black and the like) and aluminum sources (such as sodium metaaluminate, aluminum sulfate and the like), adding a template agent (such as tetraethylammonium hydroxide), an alkali source (such as sodium hydroxide) and deionized water, uniformly mixing and stirring according to a specific molar ratio to obtain an initial gel; then crystallizing the gel, and the crystallization can be carried out by using a conventional hydrothermal method or a microwave heating method; and after the crystallization is completed, the product is subjected to post-treatment such as filtering, washing, drying and high-temperature calcination, and finally, the Beta molecular sieve product is obtained. The method for rapidly preparing nano Beta molecular sieve by using the microwave synthesis method simplifies the synthesis steps, significantly shortens the crystallization time, improves the production efficiency, effectively controls the particle size of the nano Beta molecular sieve, and obtains the nano-level product with smaller particle size and more uniform distribution.

This invention relates to the field of catalysis, and discloses a method for preparing a naphthalene alkylation catalyst based on a hierarchical porous molecular sieve and its application. The preparation method includes: 1) treating a low silica-to-alumina ratio zeolite molecular sieve with a microporous structure by steam treatment or acid washing to obtain a dealuminized molecular sieve; 2) treating the dealuminized molecular sieve with a mixed aqueous solution of tetraethylammonium hydroxide and alkali to obtain a surface-rich silica-based hierarchical porous molecular sieve; 3) modifying the surface-rich silica-based hierarchical porous molecular sieve with ammonium ion exchange and calcining to obtain an alkylation catalyst, wherein the inner layer has a hierarchical porous structure with micropores and mesopores, and the outer layer is mainly mesoporous inert silica. The naphthalene alkylation catalyst prepared by this invention has a hierarchical porous structure with micropores and mesopores in the inner layer and an outer layer mainly mesoporous inert silica. This catalyst has the advantages of high selectivity, good mass transfer efficiency, and low deactivation.

The invention relates to the technical field of gemini surfactants, and belongs to a gemini surfactant for developing a negative photoresist. The invention further discloses a developing solution, the developing solution comprises the gemini surfactant for developing the negative photoresist, the weight part of the gemini surfactant is 2-10%, and the developing solution further comprises 5-15% by weight of an alkaline substance and the balance of water. The alkaline substance is one of potassium hydroxide, tetramethylammonium hydroxide and tetraethylammonium hydroxide, the concentration of the alkaline substance is 8%-12%, and the concentration of the surfactant is 4%-8%.

The invention belongs to the technical field of chemical catalysis, and provides a preparation method and application of a modified MCM-22 molecular sieve catalyst. Unroasted MCM-22 (P) is used as a raw material, organic alkali (such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide or tetrabutylammonium hydroxide) is adopted for modification treatment, and then ion exchange and roasting are performed to obtain the hydrogen type modified molecular sieve. Organic alkali has the synergistic effect of alkali treatment and structure guiding, and the crystal phase purity and framework integrity are maintained while controllable desilicication is achieved. The catalyst is used for alkylation removal reaction of thiophenic sulfur in styrene, the selectivity of mono-substituted alkylation products is remarkably improved, and side reaction of styrene polymerization is effectively inhibited. The preparation method is simple, the catalytic performance is excellent, and the catalyst has a good industrial application prospect.

The invention belongs to the technical field of zeolite molecular sieve preparation, and particularly discloses a preparation method and application of a Ni-EMT zeolite molecular sieve.The Ni-EMT zeolite molecular sieve is prepared by using a complex of nickel nitrate hexahydrate and ethylenediamine as a nickel source and a template agent and using relatively cheap tetrabutyl ammonium hydroxide and tetraethylammonium hydroxide as synergistic template agents. According to the present invention, the Ni-EMT zeolite molecular sieve is directly prepared by using the one-pot method, the prepared Ni-EMT zeolite molecular sieve has characteristics of high crystallinity, stable molecular sieve structure, large specific surface area and large pore, and compared with the traditional method, the use of the expensive and high-toxicity 18-crown ether-6 template agent is avoided, and the metal nickel is coated in the EMT molecular sieve in situ so as to achieve the purpose of the in-situ preparation of the Ni-EMT zeolite molecular sieve. According to the present invention, the nickel loading amount of the Ni-EMT zeolite molecular sieve prepared by the method can be adjusted, such that the Ni-EMT zeolite molecular sieve can be used for the catalytic reactions such as the preparation of cyclohexylbenzene through the hydroalkylation of benzene, and can be widely used in the actual industrial application.

The invention provides a crystal form E-enriched silicon-aluminum-germanium Beta molecular sieve as well as a preparation method and application thereof, and belongs to the technical field of molecular sieve material synthesis and catalytic application thereof. A framework of the molecular sieve contains silicon, germanium and aluminum elements at the same time, a powder X-ray diffraction pattern of the molecular sieve shows strongest diffraction peaks at 2theta = 9.78 + / -0.3 degrees and 22.14 + / -0.3 degrees, and the proportion of a crystal form E is not lower than 80%. The preparation method comprises the following steps: by taking tetraethylammonium hydroxide as a template agent, optimizing the molar ratio of Ge / Si / Al, optionally adding an ITQ-1 seed crystal, and carrying out hydrothermal crystallization and roasting, thereby obtaining the catalyst. The molecular sieve disclosed by the invention has a unique single-crystal hierarchical pore structure, effectively improves mass transfer limitation, shows catalytic activity, low-carbon olefin selectivity and stability which are far higher than those of a traditional ZSM-5 molecular sieve in hydrocarbon catalytic cracking, methanol-to-olefin and furfural / furfuryl alcohol etherification reactions, and has a wide industrial application prospect.

The application provides a preparation method of SAPO-34 / SAPO-5 composite molecular sieve, the SAPO-34 / SAPO-5 composite molecular sieve and application. The preparation method of the SAPO-34 / SAPO-5 composite molecular sieve provided by the application comprises S1: subjecting a first mixture comprising a silicon source, an aluminum source, a phosphorus source, a first structure directing agent and water to a first crystallization treatment to obtain a first crystallization product; S2: mixing a second structure directing agent with the first crystallization product and then subjecting to a second crystallization treatment; wherein the first structure directing agent is selected from tetraethylammonium hydroxide and / or morpholine, and the second structure directing agent is selected from tetraethylammonium hydroxide and / or morpholine. When the SAPO-34 / SAPO-5 composite molecular sieve prepared by the application is used in a methanol-to-olefin reaction, the selectivity of C4 olefin in the methanol-to-olefin reaction can be effectively improved, and the SAPO-34 / SAPO-5 composite molecular sieve has a good industrial application prospect.

The present disclosure relates to a kind of UZM-8 molecular sieve and its preparation method, catalyst and application containing UZM-8 molecular sieve, the method includes: the raw material mixture containing silicon aluminum source, first template agent, second template agent and water is carried out hydrothermal crystallization reaction and recovers product;Wherein, the first template agent is at least one selected from tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide, the second template agent is dimethyl diethyl ammonium hydroxide.Compared with the UZM-8 molecular sieve synthesized by traditional hydrothermal method, the UZM-8 molecular sieve with high crystallinity, high specific surface area and pore volume can be synthesized in the present disclosure, while the synthesis cost of molecular sieve is significantly reduced.

The application relates to the technical field of starch modification, and discloses a preparation method of hydroxypropyl modified starch, which comprises the following steps: obtaining acidified starch milk by acidifying treatment of starch, adjusting the pH of the acidified starch milk to 9-11 to obtain starch milk; uniformly mixing the starch milk, a catalyst and a propylene oxide solution, stirring the mixture at 35-45 DEG C to obtain a reactant; and obtaining the hydroxypropyl modified starch by alcohol precipitation, washing, filtration and drying of the reactant; wherein the catalyst comprises tetraethylammonium hydroxide, sodium carbonate and tetrabutylammonium bromide. The above technical scheme solves the problem of low substitution degree of the hydroxypropyl modified starch in the related art.

The invention relates to a fluorene-based polymer fluorescent probe and a preparation method and application thereof, the preparation method comprises the following steps: 1, dissolving diborate fluorene, dibromo fluorene, dibromo heteroaromatic ring and dibromo benzothiadiazole monomers in an organic solvent, and adding a catalyst and a tetraethylammonium hydroxide aqueous solution for reaction; and 2, after the reaction is finished, cooling to room temperature, precipitating in methanol, filtering, performing Soxhlet extraction, and drying to obtain the fluorene-based polymer fluorescent probe. The application method comprises the following steps: 1, dissolving the fluorene-based polymer fluorescent probe in toluene to prepare a toluene solution, adding the toluene solution into N, N-dimethylacetamide, and filtering to obtain a fluorescent probe solution; and 2, taking the fluorescent probe solution, adding the to-be-detected water sample in batches, carrying out fluorescence emission spectrum determination under excitation of a light source with the excitation wavelength of 340-390nm, drawing a fluorescence intensity change curve, and calculating the fluorescence emission spectrum intensity change value delta I before and after the to-be-detected water sample is added into the fluorescent probe solution according to the curve.

This invention relates to the field of molecular sieve technology, specifically to a SAPO-34 molecular sieve, its preparation method, and its applications. The preparation method includes: aging, pre-crystallization, and crystallization of a gel containing an aluminum source, tetraethylammonium hydroxide, a silicon source, a phosphorus source, and water; wherein the aging temperature is 40-80℃, and the aging time is 4-12 h; the pre-crystallization temperature is 90-130℃, and the pre-crystallization time is 2-24 h; and the crystallization temperature is 180-210℃, and the crystallization time is 24-50 h. The SAPO-34 molecular sieve prepared by this invention has a nanometer-sized particle size, uniform morphology, clean surface, high regularity, and the preparation operation is simple and environmentally friendly.

The invention discloses a zeolite catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalysts. The invention provides a preparation method of a zeolite catalyst. The preparation method comprises the following steps: carrying out heat treatment on aluminum-containing zeolite to remove a template agent in the aluminum-containing zeolite; the roasted zeolite is obtained. And carrying out acid treatment on the roasted zeolite to remove Al in the zeolite so as to obtain the dealuminated zeolite. The method comprises the following steps: by taking dealuminated zeolite as a silicon source and tetraethylammonium hydroxide as a template agent, adding a zinc source, and carrying out evaporation treatment to obtain a mixture; performing pre-crystallization treatment on the mixture, and adding a mineralizing agent to form gel; and carrying out crystallization treatment and roasting treatment on the gel to obtain the zeolite catalyst. When the prepared zeolite catalyst is used, thermodynamic limitation is broken through, high polylactic acid conversion rate and high methyl lactate yield are obtained at mild temperature and pressure, and the technical problems that a traditional polylactic acid methanol depolymerization catalyst is difficult to separate, poor in effect, complex to synthesize and toxic are solved.

The application discloses a kind of double-template method high crystallinity AlPO-18 molecular sieve and preparation method thereof.Step includes: phosphorus source, deionized water, aluminium source, tetraethylammonium hydroxide, tetraethylammonium chloride and seed crystal are sequentially added in hydrothermal reactor with stirring uniformity, and after aging certain time at room temperature, hydrothermal reactor is sealed, and placed in reactor high-temperature static crystallization;The hydrothermal crystallization product is washed, dried and calcined, and then high-crystallinity quadrilateral AlPO-18 molecular sieve is obtained.Compared with prior art, its significant features are simple operation, low water aluminum ratio, high crystallinity, high yield;And using double-template method, to a certain extent, reduce the amount of expensive template agent tetraethylammonium hydroxide, effectively reduce the cost, with the wide prospect of industrial production and application.

The application discloses a preparation method of nanoscale Ti-Co-beta molecular sieve, which comprises the following steps: taking tetraethyl orthosilicate or silica sol as a silicon source, titanium tetrachloride or titanium isopropoxide as a titanium source, cobalt chloride hexahydrate as a cobalt source, sodium hydroxide as an alkali source, tetraethylammonium hydroxide as a template agent, and sodium acetate or sodium benzoate as a mineralizer; after one-step hydrothermal treatment, drying and calcination, Na type Ti-Co-beta molecular sieve is obtained; and after ion exchange treatment, sodium ions are removed, and nanoscale Ti-Co-beta molecular sieve is obtained. The method has the advantages of no need of adding fluoride, simple operation, good repeatability, low cost, easy industrialization, and the like, and the prepared Ti-Co-beta molecular sieve has the advantages of nanoscale, good crystallinity, uniform distribution of Ti and Co in the zeolite framework of the beta molecular sieve, large specific surface area and rich metal active sites, and the like, and is suitable for a toluene hydroxylation reaction and has very good catalytic activity, high toluene conversion rate and phenol selectivity.

The invention provides a synthesis method and application of an H-shaped slice high-silicon mordenite molecular sieve, and belongs to the technical field of molecular sieve synthesis and application. The preparation method comprises the following steps: mixing tetraethylammonium hydroxide and long-chain pyrrolidinium salt as template agents with an alkali source, an aluminum source and a seed crystal to form silicon-aluminum sol, aging the silicon-aluminum sol, carrying out a crystallization synthesis reaction, and carrying out ammonium ion exchange, drying and roasting to obtain the H-type high-silicon slice mordenite molecular sieve (MOR). According to the synthesized H-shaped sheet high-silicon mordenite molecular sieve, the Al element is enriched in an eight-membered ring of an MOR zeolite molecular sieve skeleton structure, acid sites which are subjected to side reactions in HMOR can be effectively shielded, and the H-shaped sheet high-silicon mordenite molecular sieve has good catalytic activity and product selectivity when being applied to a reaction for synthesizing methyl acetate through carbonylation.

The application discloses a method for preparing SAPO-44 microporous molecular sieves by using palygorskite as raw material, and comprises the following steps: step A: adding palygorskite into an acid solution, uniformly mixing, placing in a hydrothermal reaction kettle for hydrothermal treatment, cooling, washing, drying, and obtaining a rod-shaped silicon source; step B: mixing an aluminum source, phosphoric acid and deionized water, uniformly stirring at room temperature, and obtaining solution a; step C: mixing the rod-shaped silicon source and tetraethylammonium hydroxide, uniformly stirring at room temperature, and obtaining solution b; step D: under the condition of stirring at room temperature, adding solution a into solution b drop by drop to form a sol-gel system; step E: transferring the sol-gel system obtained in step D into a homogeneous reactor for dynamic hydrothermal reaction; and step F: filtering, washing, drying and calcining the crystallization product to obtain high-purity and high-crystallinity SAPO-44 microporous molecular sieves. The application realizes effective utilization of silicon elements in palygorskite, reduces production cost, shortens a synthesis period, and makes the prepared SAPO-44 microporous molecular sieves high in purity and good in crystallinity, so that the application has a wide application prospect in industry.

This invention discloses an environmentally friendly and efficient 4H-SiC polishing slurry and its preparation method, belonging to the technical field of polishing compositions. The 4H-SiC polishing slurry of this invention comprises the following components: 1.5 wt.%~6 wt.% abrasive, 0.2 wt.%~0.4 wt.% photocatalyst, 2 wt.%~4 wt.% H2O2, an organic base pH adjuster to adjust the pH value of the 4H-SiC polishing slurry to 8~11, and the balance being water; wherein the organic base pH adjuster includes at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline hydroxide. The composition design of this invention is simple and easy to prepare. It has a high material removal rate for 4H-SiC, significantly reduces surface roughness after polishing, and is environmentally friendly and pollution-free, possessing the advantages of being environmentally friendly and efficient, and has broad application prospects in high-precision polishing of 4H-SiC.

The invention relates to the technical field of gemini surfactants, and belongs to a gemini surfactant for developing a positive photoresist. The invention also discloses a developing solution, the developing solution comprises the above gemini surfactant for developing the positive photoresist, the weight part of the gemini surfactant is 0.2-1.0%, the developing solution also comprises 0.5-2.5% by weight of an alkaline substance and the balance of water, and the alkaline substance is at least one of tetramethylammonium hydroxide and tetraethylammonium hydroxide.

This invention provides a low-temperature, high-activity rare-earth metal-modified nickel-based mesoporous catalyst, its preparation method, and its application. It relates to the field of CO2 methanation catalyst preparation technology. First, nickel nitrate hexahydrate, tetraethylammonium hydroxide, and triethylamine are synthesized into a 20wt% Ni / F-SiO2 precursor powder. Then, lanthanum nitrate hexahydrate and cerium nitrate hexahydrate are dissolved in deionized water. The lanthanum nitrate aqueous solution is added dropwise to the 20wt% Ni / F-SiO2 precursor powder for impregnation, followed by drying to obtain a single-modified powder. Next, a cerium nitrate aqueous solution is added dropwise to the single-modified powder for impregnation, followed by drying to obtain a double-modified powder. Finally, the double-modified powder is calcined to obtain a LaCe-Ni / F-SiO2 catalyst. Therefore, by using a gel-assisted impregnation method to synergistically introduce La and Ce as dual rare-earth promoters, the carbonate-related modification of La and Ce species optimizes the surface alkalinity of the catalyst and adjusts the surface chemical state of Ni. Simultaneously, the catalyst exhibits high catalytic activity at a relatively low reaction temperature.

The invention provides a synthesis method and application of an H-type high-silicon-wafer-shaped MOR zeolite molecular sieve, and belongs to the technical field of synthesis and application of molecular sieves. The method comprises the following steps: adding an aluminum source into a mixed solution containing an alkali source, tetraethylammonium hydroxide, long-chain bipiperidine onium salt and water to form slurry, adding a silicon source and a small-grain MOR zeolite molecular sieve seed crystal into the slurry, uniformly mixing to obtain silicon-aluminum sol, aging the silicon-aluminum sol, carrying out a crystallization synthesis reaction, carrying out ammonium ion exchange on the obtained crystallization product, and drying to obtain the small-grain MOR zeolite molecular sieve. And filtering, washing, drying and roasting to obtain the H-type high-silicon-wafer-shaped MOR zeolite molecular sieve. According to the molecular sieve synthesized by the invention, the Al element is enriched in an eight-membered ring of an MOR zeolite molecular sieve skeleton structure, the quantity of B acid in the eight-membered ring is increased, and the molecular sieve has a small-grain morphology feature structure, can effectively shield acid sites in side reaction in HMOR, is applied to a reaction for synthesizing methyl acetate by carbonylation of dimethyl ether, and has a good application prospect. The catalyst has the advantages of high catalytic activity, good product selectivity, simple preparation process and easy industrial amplification.