24results about How to "Maintain catalytic activity" patented technology

The invention relates to a metal additive modified Pt-loaded CeO2 catalyst, preparation and application thereof in CO oxidation, and belongs to the technical field of industrial catalysis. The preparation process of the catalyst mainly comprises the following steps: respectively dissolving cerium salt, platinum salt and auxiliary metal salt in deionized water to prepare corresponding precursor solutions; then, mixing the three solutions, and dropwise adding ammonia water under a stirring condition until yellow precipitates are generated; and finally, drying and washing the precipitate, and calcining the solid powder in a proper atmosphere to obtain the assistant metal modified Pt / CeO2 catalyst. La, Pr, Nd or Sm auxiliary metal is introduced into the Pt / CeO2 catalyst, so that the CO catalytic oxidation performance of the catalyst can be improved, and the poisoning resistance of the catalyst in an SO2-containing environment can be enhanced. The method has important significance in the actual industrial application, especially in the catalytic oxidation process under the condition of treating complex flue gas.

The invention discloses a multilayer nanostructure metal hydride and a preparation method thereof.The preparation method comprises the steps that transition metal ion salt and a carbon material are added into a polar solvent to be mixed, heating and stirring are conducted to obtain solid powder, and the solid powder is subjected to a hydrogen thermal reduction reaction to obtain a functionalized carbon material; a metal hydride raw material and a functionalized carbon material are added into an organic solvent, ultrasonic treatment and mixing are carried out, a mixed solution is obtained, and the metal hydride raw material is a mixture of an alkyl metal Mg compound or an alkyl metal Li compound and a borane compound; and in a hydrogen atmosphere, carrying out solvothermal reaction on the mixed solution, and then centrifuging, washing, filtering and drying to obtain the multilayer nanostructure metal hydride. The multilayer nano-structure metal hydride prepared by the preparation method has relatively high hydrogen absorption and hydrogen storage capacity.

The invention discloses a T7 RNA (Ribonucleic Acid) polymerase mutant, and the T7 RNA polymerase mutant comprises any one or more of the following amino acid mutation sites: W797L, P657K, Y846R, M306K, N601E, P476E, S606V, K642G, P742G, I117L, Q786L, S430P, L446F or T375K, and the T7 RNA polymerase mutant has RNA polymerase activity. The invention also discloses an application of the T7 RNA polymerase mutant in in-vitro transcription, non-coding RNA synthesis, RNA drug synthesis, in-vivo protein expression or cell-free protein expression.

The invention discloses a low-density flame-retardant organic silicon foam composition, a silicon rubber foam material and a preparation method of the low-density flame-retardant organic silicon foam composition and the silicon rubber foam material, and the foam composition comprises the following components in parts by weight: (A) 100 parts of organopolysiloxane; (B) 5-100 parts of a reinforcing filler; (C) 20-100 parts of a composite flame-retardant filler; (D) 1-10 parts of a structuring control agent; (E) 1-10 parts of a foaming agent; (F) 1-10 parts of an auxiliary foaming agent; (G) 1-10 parts of hydrogen-containing siloxane; (H) 0.01-3 parts of a platinum group metal compound catalyst; (I) 0.01-1 part of an inhibitor; according to the organic silicon foam composition, the component (F) and the component (E) are introduced, so that the foaming speed and the curing speed can be better matched, the organic silicon foam composition has a relatively high foaming ratio after being cured, the density of a material can be remarkably reduced, and meanwhile, foam pores of foam are uniform and fine in size.

The present application relates to a kind of catalyst for hydrogen chloride oxidation preparation chlorine and its preparation method and application.The preparation method includes: after carrier substrate, metal tantalum powder, binder solution are mixed, extrusion forming is obtained green body, the green body is prepared composite carrier by calcination, the mass fraction of metal tantalum powder in the composite carrier is 5%-30%;Inorganic salt containing catalytically active element is made into solution and is placed in the composite carrier, and after drying, pre-product is obtained, and the pre-product is prepared catalyst by calcination.The preparation method described in the present application prepares high thermal conductivity composite carrier, not only effectively improves the heat conduction efficiency of catalyst, guarantees the effective activity of catalyst, but also guarantees the stability of composite carrier, thereby effectively prolongs the life of catalyst.

The invention provides a fuel cell ORR catalyst and a preparation method and application thereof. The fuel cell ORR catalyst comprises a nitrogen-doped porous carbon core, a nitrogen-doped porous carbon coating layer arranged on the surface of the nitrogen-doped porous carbon core, and doped metal simple substances distributed in pore channels of the nitrogen-doped porous carbon core and the nitrogen-doped porous carbon coating layer, the ratio of micropores in the nitrogen-doped porous carbon core is gt; the total proportion of mesopores and macropores in the nitrogen-doped porous carbon core; the ratio of micropores in the nitrogen-doped porous carbon coating layer is lt; the total ratio of mesopores to macropores in the nitrogen-doped porous carbon coating layer is 1: 1. The nitrogen-doped porous carbon structure monatomic catalyst with multiple micropores inside and multiple mesopores / macropores outside is obtained through gradient pore channel design in space in combination with a CVD coating technology, and dissolution and loss of metal elementary substances are greatly inhibited while the catalytic activity of the catalyst is guaranteed, so that the service life of the catalyst is prolonged.

The invention relates to the technical field of organic liquid hydrogen storage, in particular to dehydrogenation equipment and method in the organic liquid hydrogen storage process, the dehydrogenation equipment comprises a hydrogen storage organic liquid dehydrogenation tank, the middle of the hydrogen storage organic liquid dehydrogenation tank is fixedly connected with a catalyst replacement track, and the inner side of the inner wall of the catalyst replacement track is sleeved with an annular chain; a plurality of dehydrogenation catalyst beds are fixedly connected to the outer side of the annular chain, material ports are formed in the two sides of the top of the outer wall of the catalyst replacement rail correspondingly, and a connecting pipeline and a dehydrogenation catalyst regeneration device are fixedly connected to the upper portions of the material ports. The hydrogen storage organic liquid dehydrogenation device has the advantages that the catalyst replacement track with the dehydrogenation catalyst bed is arranged in the middle of the hydrogen storage organic liquid dehydrogenation tank, so that the dehydrogenation catalyst bed carrying a dehydrogenation catalyst can move on the catalyst integrated track, and the dehydrogenation catalyst in the hydrogen storage organic liquid dehydrogenation tank is replaced; the dehydrogenation equipment can replace the dehydrogenation catalyst while dehydrogenation treatment is carried out.

The application provides a method for preparing two-dimensional titanium dioxide microwires by using a high-viscosity system and application. The method comprises the following steps: providing a high-viscosity system, wherein the high-viscosity system is an aqueous solution of guar gum hydroxypropyltrimethyl ammonium chloride; and performing high-speed shearing treatment on the high-viscosity system; adding liquid tetrabutyl titanate into the high-viscosity system, stirring, centrifugal drying, and obtaining the two-dimensional titanium dioxide microwires. The preparation method is simple, reaction conditions are normal temperature and normal pressure, the method is easy to control, mass production is realized, and the prepared two-dimensional titanium dioxide microwires have good catalytic activity.

The invention provides special phenyl silicone oil for cosmetics and a preparation method of the special phenyl silicone oil, and belongs to the technical field of material chemistry. The preparation method comprises the following steps: carrying out prepolymerization and ring-opening copolymerization reaction on raw materials including trimethyl triphenyl cyclotrisiloxane, diphenyl double-end socket and a solid catalyst to obtain a copolymer; carrying out reduced pressure distillation on the copolymer to obtain special phenyl silicone oil; the solid catalyst is obtained by the following steps: preparing a magnetic core material containing an anionic polymer; carrying out coating treatment on the magnetic core material by adopting an organic matter containing a cationic polymer to obtain magnetic particles; preparing a silicon dioxide porous carrier by adopting a raw material comprising magnetic particles; ammonium dihydrogen phosphate is loaded on a silicon dioxide porous carrier, and an acidic solid catalyst is obtained. According to the method, the catalyst which is good in catalytic effect and convenient to recycle and recycle is adopted, so that the environment-friendly degree of phenyl silicone oil production is improved, and the production cost is reduced.

The invention provides environment-friendly vinyl silicone oil and a preparation method thereof, and belongs to the technical field of material chemistry. The preparation method of the environment-friendly vinyl silicone oil comprises the following steps: feeding cyclic polysiloxane and an end-capping reagent into a reaction device, and heating and dehydrating under inert gas protection and vacuum conditions; adding a solid catalyst into the reaction device, and heating for reaction; adjusting substances in the reaction device to be neutral, and performing reduced pressure distillation to remove low-boiling-point substances to obtain vinyl silicone oil; the solid catalyst is prepared by the following steps: preparing a magnetic core material; coating the surface of the magnetic core material to obtain magnetic particles; preparing a porous carrier from a raw material comprising magnetic particles; and loading the catalyst on a porous carrier to obtain the solid catalyst. According to the method, the catalyst which is good in catalytic effect and convenient to recycle and recycle is adopted, so that the environment-friendly degree of vinyl silicone oil production is improved, and the production cost is reduced.

The application belongs to the field of petroleum refining catalysis technology, and discloses a ZSM-5 additive for increasing propylene production and a preparation and use method thereof. In the method, waste filtrate prepared by using SAPO-34 molecular sieve is used to improve the stability of the molecular sieve under a high-temperature water-containing atmosphere, prevent the molecular sieve channels from being blocked by excessive phosphorus elements, reduce environmental pollution caused by the waste filtrate, improve the specific surface area of the ZSM-5 additive and the stability of the product, realize the dual effects of the stabilization of the molecular sieve by the phosphorus elements and the protection of the organic ammonium channels, complement the low-molecular-weight ammonium polyacrylate, white carbon black and phosphorus aluminum binder, construct a hierarchical pore structure (micropore-mesopore-macropore hierarchical pore), and then obtain the additive with a specific surface area of 150-170 m 2 / g, an addition amount of only 10 wt% can achieve a propylene production effect better than that of 20 wt% of a commercially available additive, the catalyst procurement cost of a refinery is greatly reduced, and the slurry oil yield is reduced and the heavy oil cracking capacity is improved.

The invention discloses a CuFeS2 and FeS2 composite Fenton-like catalyst as well as a preparation method and application of the CuFeS2 and FeS2 composite Fenton-like catalyst. According to the preparation method disclosed by the invention, the natural pyrite does not need a further forming process and has good adsorbability on copper ions, and a Cu element is embedded into a pyrite crystal lattice through a citrate dipping-anaerobic calcining process, so that the CuFeS2-FeS2 composite Fenton-like catalyst with a heterostructure is formed. The catalyst disclosed by the invention can activate peroxymonosulfate and hydrogen peroxide to generate active oxygen species, so that different types of organic pollutants such as sodium dodecyl benzene sulfonate, tetracycline hydrochloride, rhodamine B and the like which are common in water, such as surfactants, antibiotics, dyes and the like can be quickly degraded and mineralized. The granular catalyst with good catalytic performance is prepared from the pyrite with huge reserves in nature as a raw material through a simple dipping-calcining process, and the method has the advantages of high feasibility, low cost, easiness in industrial preparation and the like.

The application discloses a kind of photocatalytic nanocomposite and its preparation method and application, belong to nanocomposite technical field, first synthesis CuInS2 quantum dot powder, a layer of carbon is covered on the surface of CuInS2 quantum dot powder, then amino is introduced by silane coupling agent modification, then modified carbon composite CuInS2 quantum dot powder is loaded on tubular carbon nitride powder formed.The tubular structure of tubular carbon nitride powder is conducive to CuInS2 quantum dot dispersion on its surface or inside, so that the active site of CuInS2 quantum dot powder is fully exposed, the band gap energy of CuInS2 quantum dot powder is about 1.53eV, when being irradiated, electron and hole pair can be generated, can promote the separation of photoinduced electron and hole to improve the activity of catalyst, and the dense carbon layer on CuInS2 quantum dot powder can form physical barrier to prevent peroxide from directly contacting with sulfur ion.

The invention relates to the technical field of chemical catalysts, in particular to a catalyst for preparing 2-tert-butylhydroquinone and a preparation method and application thereof.The catalyst comprises a hierarchical pore H beta molecular sieve, active metal is loaded in a framework of the hierarchical pore H beta molecular sieve, and the active metal is one or more of La, Ce and Zn. The catalyst adopts the hierarchical pore H beta molecular sieve as a skeleton, so that the diffusion limitation of the traditional microporous molecular sieve can be effectively broken through, and the occurrence of side reactions is reduced while the intrinsic rate of the reaction is greatly improved. La, Ce and Zn active metals are introduced into a hierarchical pore H beta molecular sieve framework to form a high-activity catalytic center synergistic system, and the reaction process is enhanced. Compared with the traditional liquid acid catalyst and ion exchange resin, the catalyst has the characteristics of simple process, easiness in recovery, no pollution, good high-temperature stability, high catalytic activity, good selectivity and low cost, and solves the core problems of low activity, heavy pollution and high cost of the traditional catalyst.

The invention discloses a preparation method of a Pt-K bimetallic molecular sieve catalyst. Specifically, tetrapropylammonium hydroxide, deionized water and tetraethyl orthosilicate are mixed at 25-30 DEG C, stirred for reaction to obtain a hydrogel, platinum nitrate, potassium nitrate and ethylenediamine solution are added into the deionized water, mixed to obtain a Pt-K precursor solution, slowly dripped into the hydrogel under ice-water bath ultrasonic conditions, the mixture is hydrothermally reacted at 150-180 DEG C for 24-72 hours, the reaction product is separated into a solid and a liquid, the solid is alternately washed with ethanol and deionized water with a volume concentration of 45-55% until the pH value of the washing solution is less than 8, and dried and roasted to obtain the catalyst. The preparation method of the catalyst is simple in process, high in catalytic activity and stable in catalytic performance, and the noble metal is stably applied in the chemical chain CH4 reforming coupled CO2 reduction reaction by in-situ synthesis and adding a co-catalyst, and the catalyst has good catalytic activity and stability.

A method for recovering organic tin in a vinyl ether compound transesterification kettle liquid, comprising the following steps: 1) taking the vinyl ether compound transesterification kettle liquid, cooling to-10-40 DEG C, standing, until crystals are precipitated in the transesterification kettle liquid, filtering, or, cooling to-10-40 DEG C, adding 0.1-5% of organic tin powder in mass fraction to the transesterification kettle liquid, stirring and mixing uniformly, then standing, until crystals are precipitated in the transesterification kettle liquid, filtering; 2) adding a basic solution with a concentration of 5-8 wt% to the crystals obtained by filtering, in a mass ratio of 1:0.5-10, and heating to 25-60 DEG C, until flocculent substances appear on the surface of the basic solution, and filtering the lower aqueous phase; 3) washing the crystals obtained by filtering with water, then washing with an organic solvent, drying, to obtain organic tin. The process condition is mild and the operation is convenient, the recovered organic tin can be used repeatedly, the production cost of enterprises is reduced, and environmental pollution is avoided.

The invention relates to the technical field of composite catalysts, in particular to a preparation method of a conductive perovskite-molecular sieve composite catalyst for electrocatalytic purification of organic waste gas, which comprises the following steps: S1, directly mixing a rare earth salt, a transition metal salt, an alkaline earth salt, a complexing reagent and a small amount of deionized water according to a certain proportion, and stirring for a period of time to form sticky slurry, obtaining a mixture; and S2, directly putting the mixture in the step S1 into a muffle furnace for calcining, heating to a certain temperature at a certain heating rate, and maintaining for a period of time to obtain the conductive perovskite, and S3, ultrasonically dispersing a molecular sieve in a 70% ethanol solution, adding the conductive perovskite obtained in the step S2, stirring for a period of time, and drying to obtain the conductive perovskite-molecular sieve composite catalyst. The composite catalyst prepared by the preparation method disclosed by the invention has relatively high structural stability, relatively strong catalytic activity and relatively low operation temperature, and can promote efficient low-temperature degradation of VOCs (Volatile Organic Compounds).

The invention discloses a preparation method and application of an epsilon-caprolactone catalyst prepared by cyclohexanone B-V oxidation, and belongs to the technical field of catalysts. Heteropolyacid is introduced in the preparation process of the TS-1 molecular sieve, the heteropolyacid intervenes in the crystallization process of the TS-1 molecular sieve through an in-situ bonding method, one Si-O bond of tetra-coordinated Si in the TS-1 molecular sieve is opened, and the Si-O bond and a central atom in the heteropolyacid form a new chemical bond, so that the TS-1 molecular sieve is prepared. The effect that heteropolyacid uniformly and firmly grows on the pore channels and the surface of the TS-1 molecular sieve is achieved. According to the catalyst synthesized by the scheme, the original MFI topological structure of the TS-1 molecular sieve can be maintained, the large specific surface area of the catalyst is effectively ensured, the contact area of a catalytic system is increased, and the problem that heteropoly acid is difficult to separate in the catalytic system can be solved.

The invention discloses an anti-static wafer PVCWafer protective film and a preparation method thereof, and belongs to the technical field of PVC thin films, hydroxyl on a polyborosiloxane molecular chain and silicon hydroxyl on the surface of modified nickel composite hollow carbon fiber are condensed, polyborosiloxane / hollow carbon fiber is used as rigid filler and can be uniformly dispersed in a polyvinyl chloride matrix, and the reason is that the rigid filler can be uniformly dispersed in the polyvinyl chloride matrix, so that the anti-static wafer PVCWafer protective film is prepared. Polyborosiloxane molecules contain a large number of silicon-oxygen bonds and boron-oxygen bonds, the groups have high polarity, compatibility with polyvinyl chloride can be improved, organosiloxane chain segments of polyborosiloxane have certain flexibility, the organosiloxane chain segments can serve as flexible buffer layers, rigidity difference between polyborosiloxane / hollow carbon fibers and polyvinyl chloride is relieved, and therefore the service life of the hollow carbon fibers is prolonged. The interface stress concentration is reduced, and the compatibility of the two is further improved.

The application discloses a general method for cross-coupling of nickel-catalyzed aryl halide and amine, and belongs to the field of green chemical industry. In a nitrogen-containing solvent, only a cheap and commercially available nickel salt and a base are added, and no additional ligand is designed, so that aryl halide and amine can be efficiently coupled to prepare aryl amine compounds. In the method, the nitrogen-containing solvent simultaneously serves as a metal ligand, the substrate has wide universality, has good compatibility with various functional groups, and the yield of the product separation can reach 99% at most. The process has good scalability, and has been stably produced on a hundred gram scale; the solvent and the ligand can be efficiently recycled and reused for multiple times through simple physical or chemical means. The route has the advantages of easy availability of raw materials, simple operation, high atomic economy, and compliance with the principles of green chemistry and sustainable synthesis.

This application relates to the field of catalytic conversion technology of organohalides, specifically disclosing a catalytic disproportionation reaction method for chlorofluorocarbons. The method includes the following steps: using two or more chlorofluorocarbons with different chlorine / fluorine atom numbers as raw materials, and reacting them in a closed reactor in the presence of aluminum chlorofluoride and / or amorphous aluminum fluoride catalyst at a temperature of 50-400℃ and a pressure of 0.1-5MPa for 1-24 hours, causing directional transfer and recombination of chlorine and fluorine atoms between the raw material molecules to generate a target product with a chlorine / fluorine atom number between that of the raw materials; wherein the aluminum chlorofluoride has the chemical formula AlCl₂. x F 3‑x 0 < x < 3; the chemical formula of the amorphous aluminum fluoride is AlF3·nH2O, where n is 0 or a positive integer. The target product is generated with high selectivity by promoting the exchange of chlorine / fluorine atoms between different CFC molecules through aluminum chlorofluoride and / or amorphous aluminum fluoride catalysts.

The invention relates to the field of oxygen reduction electrocatalysts, and discloses a hollow carbon nanotube catalyst, a preparation method thereof, a battery and an electric device. According to the preparation method, the reaction time is taken as a variable through a pipe diameter regulation strategy, zinc oxide nano materials with different pipe diameters are prepared by a water bath synthesis method which is easy to reproduce and are used as templates and are attached with ZIF-8, the prepared small-pipe-diameter zinc oxide nanotube is more easily and completely carbonized, zinc ions are volatilized, a hollow carbon nano structure is obtained, a layered network structure is presented, the porosity is high, and the preparation method is simple and convenient. The flux and the purity are high. According to the preparation method, the reaction conditions are defined, the step of removing impurities through acid pickling is reduced, then the product collection amount is increased, and the catalytic activity of the carbon-based catalyst is guaranteed while the material pyrolysis temperature is reduced.

This invention discloses a method for preparing a platinum-manganese composite monolithic metal substrate catalyst, comprising the following steps: A. Surface treatment of the metal substrate; B. Preparation of a manganese-containing precursor solution; C. Immersion of the surface-treated metal substrate in the manganese-containing precursor solution to obtain a metal substrate with a thin active layer of manganese oxide; D. Immersion of the metal substrate with the manganese oxide active layer first in a platinum ethylenediaminetetraacetic acid complex solution, and then in a sodium borohydride solution I to obtain a metal substrate with platinum seed crystals deposited on its surface; E. Preparation of a platinum-containing precursor solution; F. Immersion of the metal substrate with platinum seed crystals deposited on its surface in the platinum-containing precursor solution, adding sodium borohydride solution II dropwise during the immersion process to obtain the platinum-manganese composite monolithic metal substrate catalyst. The catalyst prepared by the method of this invention exhibits high decomposition catalytic activity, long service life, and high cost-effectiveness.

This invention discloses a rhodium-silicon catalyst, its preparation method, and its application. The catalyst is a Rh / SiO2 catalyst, comprising a support, a silicon dioxide support, and an active component. The Rh species exist in one or more forms, namely Rh clusters or Rh nanoparticles formed by the aggregation of Rh clusters. Based on the total mass of the Rh / SiO2 catalyst, the loading of Rh species is 0.2-2.0 wt%; the average particle size of the Rh species is 0.7-2.0 nm. This invention uses a water-in-oil reverse microemulsion method to prepare the Rh / SiO2 catalyst in one step. By adjusting the loading of Rh, the average particle size of the Rh species can be controlled. When the Rh species in the catalyst of this invention exist in the form of Rh clusters with a particle size of 1.0 nm, its application in the heterogeneous catalytic hydroformylation of formaldehyde exhibits advantages such as high reactivity, high selectivity for ethanolaldehyde, high stability, and easy separation and recovery.