1876 results about "Side reaction" patented technology

The invention discloses a modified carbon-coated sodium manganese ferric phosphate pyrophosphate / sodium ferric phosphate pyrophosphate positive electrode material as well as a preparation method and application thereof, and relates to the technical field of new energy materials. The preparation method comprises the following steps: preparing MnFe-MOF from a manganese source, a first iron source and a first organic ligand under a hydrothermal reaction; a second iron source, the MnFe-MOF and a second organic ligand are subjected to a hydrothermal reaction, and MnFe-MOF / Fe-MOF is obtained; uniformly mixing with a sodium source and a phosphorus source, and sintering to obtain a positive electrode material; and carrying out high-temperature gas-phase etching treatment to obtain the fluorine-doped carbon-coated modified sodium manganese ferric phosphate pyrophosphate / sodium ferric phosphate pyrophosphate positive electrode material. The material disclosed by the invention has a coating modified structure, so that an interface side reaction caused by direct contact between sodium ferromanganese phosphate and an electrolyte can be effectively avoided, a manganese dissolution phenomenon is reduced, and the structural stability of the material is improved; and meanwhile, the material has high conductivity, excellent structural stability, excellent long cycle life and excellent rate capability.

The present application relates to the technical field of polyimides and relates to a preparation method for a high-performance polyimide and an application thereof, aiming to solve the problems in the prior art such as numerous side reactions and severe impact on transparency caused by an excessively high imidization reaction temperature during the use of a high-temperature thermal imidization method for the preparation of polyimides. The preparation method comprises: (1) preparing a polyamic acid solution; (2) adding a chemical catalyst and a polyamic acid solution to partially complete an imidization reaction; (3) adding an end group auxiliary agent, performing coating with the solution, heating, and maintaining the heat to complete the imidization reaction; and (4) carrying out high-temperature treatment to obtain a high-performance polyimide. The present application can significantly reduce numerous side reactions present in a traditional imidization reaction, eliminate an adverse effect of high-temperature imidization on the optical performance, greatly improve the mechanical properties, heat resistance, optical performance, etc. of a material, and also achieve both high heat resistance and high transparency.

The invention discloses a reaction device based on dichlorobenzonitrile synthesis and a use method thereof, and relates to the field of reaction devices.According to the technical scheme, the reaction device comprises a reaction tank and a cover located at the top end of the reaction tank, a heating interlayer is arranged on the reaction tank, and a spiral conveying pipe surrounding a reaction cavity in the middle of the reaction tank is arranged in the heating interlayer; the heating medium is conveyed through the spiral conveying pipe, and the gap between the heating interlayer and the spiral conveying pipe is filled with the heat preservation material, so that the heating medium is conveyed around the reaction cavity in the heating interlayer through the spiral conveying pipe, and the spirally distributed conveying pipe can enable the heating medium to uniformly act on the outer wall of the reaction cavity; heat loss is reduced through the heat preservation material between the heating interlayer and the spiral conveying pipe, accurate control and uniform distribution of the reaction temperature are achieved, side reactions caused by local overheating are avoided, and therefore generation of polychlorinated impurities is reduced, and the purity of the dichlorobenzonitrile product is improved.

The invention relates to the technical field of aerogel, in particular to flexible flame-retardant aerogel and a preparation method thereof.The flexible flame-retardant aerogel is prepared from modified graphene, modified polyvinyl alcohol, silver nanowires, phytic acid and epoxy resin E-51; the furan group is introduced into the aerogel through the modified graphene, the furan group and the maleimide group are subjected to a D-A reaction, an adhesive is prevented from being used when the aerogel is bonded with a screen backboard, the D-A reaction is reversible, and lossless reworking can be realized. PVA and epoxy resin E-51 are added together, so that the heat resistance and mechanical strength of the material are improved. PVA is grafted with a large-steric-hindrance amine group, weak interaction with a furan group is generated, side reaction with an epoxy group of epoxy resin E-51 is avoided, and when aerogel is bonded to an OLED screen backboard, the protective layer is reversibly released, so that D-A reaction can be smoothly carried out. The hydrophobic treatment of the modified graphene and the modified grafting of the polyethylene to the mPEG can effectively improve the agglomeration of the modified graphene and ensure the uniform dispersion of the modified graphene.

The invention discloses an omariglitazone intermediate as well as a synthesis method and application thereof, and belongs to the technical field of pharmaceutical chemistry synthesis. The invention provides a synthesis method of an omarigliflozin intermediate and application of the intermediate in synthesis of omarigliflozin. The key of the synthesis method provided by the invention lies in the deprotection process of polycyclic indole amide, nitrile groups are not hydrolyzed, indole carboxylic acid is generated with high selectivity, molecular lactamization is avoided in the condensation process with polycyclic imine B, and expensive amidation reagents such as HATU are not needed in the process, so that the synthesis method is simple and easy to implement. And the purpose of preparing omariglitazone with low cost and high yield is achieved. The synthesis method has the advantages of easily available raw materials, mild reaction conditions, small side reaction influence, simplicity and convenience in operation and high yield, improves the yield, is easy to purify, and is suitable for industrial production of omariglitazone.

The invention provides a bio-based 1, 4-butanediol composition as well as a preparation method and application thereof, and the bio-based 1, 4-butanediol composition comprises bio-based 1, 4-butanediol, 4-hydroxybutyric acid-(4-hydroxyl) butyl ester and bis (4-hydroxyl) dibutyl ether. The total mass content of 4-hydroxybutyric acid-(4-hydroxyl) butyl ester and bis (4-hydroxyl) dibutyl ether in the bio-based 1, 4-butanediol composition is 51 to 220 ppm. The bio-based 1, 4-butanediol composition has low hygroscopicity, and can maintain low water content after long-term storage; meanwhile, when the bio-based 1, 4-butanediol composition is used for polyester synthesis, the esterification time can be shortened, the reaction efficiency can be improved, side reactions can be reduced, and a polyester product with better damp-heat resistance stability can be obtained.

The invention relates to the field of fine chemical engineering, and discloses a green process for preparing chloramine T by a continuous flow reactor. The method comprises the following steps: respectively pumping p-toluenesulfonamide, a sodium hydroxide solution and a sodium hypochlorite solution into a micro-channel mixer for instantaneous mixing, and carrying out chlorination reaction in a multi-stage temperature control tubular reaction unit; the concentration of free chlorine is detected on line at an outlet, and the flow rate of a chlorine source is dynamically adjusted through a PID algorithm, so that closed-loop control is realized; the reaction liquid is directly crystallized and separated to obtain the product without alkali wash. The system comprises a base solution and chlorine source conveying subsystem, a micro-channel mixer, a multi-stage reaction unit, an online monitoring module, a central controller and a crystallization unit. The side reaction is inhibited from the source, so that the free chlorine is less than or equal to 0.5 mg / L, the alkali washing step is omitted, the COD (Chemical Oxygen Demand) of the wastewater is reduced by more than 80%, the product purity is more than or equal to 99.5%, and the productivity is improved by 3 times.

The invention provides a CoCe-SNC catalyst and a preparation method and application thereof, and belongs to the technical field of hydrogen fuel cell / metal air cell cathode catalysts. The preparation method comprises the following steps: mixing and grinding a metal organic framework ZIF-8 and KSCN, carrying out first pyrolysis, compounding the obtained nitrogen and sulfur-containing co-doped carbon with two metal complexes Co-PM and Ce-PM, and carrying out second pyrolysis to obtain the CoCe-SNC diatomic catalyst. According to the invention, the two-dimensional lamellar structure carbon material and the asymmetric coordination diatomic metal are compounded, so that the catalytic performance of the whole catalyst is improved, and meanwhile, the yield of hydrogen peroxide generated by side reaction is reduced. The catalyst is applied to a hydrogen fuel cell / metal air cell, and the defects that in the prior art, a noble metal catalyst is high in cost, and a non-noble metal catalyst is low in catalytic activity, high in hydrogen peroxide yield, poor in catalyst stability and the like are overcome.

The invention relates to the technical field of chemical production, in particular to a method for efficiently synthesizing epichlorohydrin. The method provided by the invention comprises the following steps: adding a mixed solution of chloropropene and methanol and part of hydrogen peroxide into a reactor; then injecting residual hydrogen peroxide through a middle-section feeding hole of the reactor; constant-temperature circulating water is adopted to control a front-section temperature control area of the reactor to be at a first temperature, a middle-section temperature control area of the reactor to be at a second temperature and a rear-section temperature control area of the reactor to be at a third temperature, and the third temperature, the first temperature and the second temperature are gradually increased in sequence. The method provided by the invention can effectively solve the problems of side reaction increase, too fast catalyst deactivation and the like caused by local overheating of the fixed bed reactor, and significantly improves product selectivity and production efficiency.

The invention relates to the technical field of fine chemical engineering and flame retardant preparation, and discloses a preparation method of bromo-triazine capable of improving thermal stability, and the preparation method comprises the following steps: mixing phenol, water and dichloromethane, controlling the temperature, and carrying out oxidative bromination reaction to prepare an organic phase containing tribromophenol; then, under the action of an organic amine catalyst, carrying out condensation reaction on the organic phase, liquid caustic soda and cyanuric chloride; after the reaction, washing with water to remove impurities; and in the presence of process water, firstly controlling the temperature at 38-42 DEG C for azeotropic desolvation, then raising the temperature to 85-95 DEG C for high-temperature crystallization and crystal growing, and finally cooling, filtering and drying to obtain the bromo-triazine product. By utilizing the high selectivity of the organic amine catalyst and a two-stage azeotropic crystallization process, the side reaction is effectively reduced, the solvent wrapped in the crystal is eliminated, the prepared product is high in main content and extremely low in volatile component, the temperature can reach 370 DEG C or above when the thermal weight loss is 2%, and the thermal stability is remarkably improved.

The invention relates to the technical field of new material application, and discloses a magnetic bead material for enriching a sulfydryl peptide fragment and a preparation method thereof.The magnetic bead material prepared from micron carboxyl magnetic beads, dodecane dicarboxylic acid dihydrazide and SPSP has a long chemical reaction connecting arm, so that a reaction group has the better freedom degree, the reaction with sulfydryl is better facilitated, and the magnetic bead material can be used for enriching the sulfydryl peptide fragment. The enrichment efficiency is relatively high. When the magnetic bead material is prepared, micron carboxyl magnetic beads and dodecane dicarboxylic acid dihydrazide are based on hydrazine group and carboxyl condensation, the condensation reaction is more selective and more stable, the reaction is carried out under a milder condition, the reaction product is stable, and the reaction efficiency is higher at a lower reaction temperature. Dodecane dicarboxylic acid dihydrazide and SPSP are based on a reaction of N-succinimide and hydrazine, N-succinimide has high specificity to amino-containing molecules, side reactions are reduced, the reaction is generally carried out at room temperature, strong acid and alkali conditions are not needed, and protection of other sensitive groups is facilitated.

The invention provides an all-silicon molecular sieve confined Pt-based bimetallic catalyst and application thereof in preparation of propylene through propane dehydrogenation. The preparation method comprises the following steps: mixing a silicon source, a template agent, a Pt precursor, an auxiliary element Cu precursor and the like by adopting an in-situ synthesis method, synthesizing under a hydrothermal condition, washing, drying, roasting and reducing to obtain the Pt-based bimetallic molecular sieve catalyst. According to the present invention, the pure silicon molecular sieve Silicalite-1 (S-1) is adopted as the carrier, such that the good carrier characteristics of high thermal stability, low acidity, rich pore structure and the like are provided, and the silicon hydroxyl group (Si-OH) in the S-1 pore channel can further provide the metal species anchoring effect so as to easily disperse and limit the active site; and the Cu auxiliary agent improves the metallicity of Pt. The synergy of the two significantly improves the performance of propylene preparation by direct dehydrogenation of propane. The synthesized PtCu-coated S-1 catalyst is low in Pt loading capacity, Pt and Cu are highly dispersed, side reactions such as deep dehydrogenation of propylene can be inhibited, and good stability is achieved.

The invention discloses a methylal production raw material mixer and a working method thereof. The methylal production raw material mixer comprises a kettle body, the outer wall of the kettle body is fixedly sleeved with a bottom sleeve, a plurality of supporting legs are arranged on the outer side wall face of the bottom sleeve, and a discharging valve is arranged at the lower end of the kettle body; the invention relates to the technical field of methylal production technologies, and has the beneficial effects that liquid formaldehyde is intermittently dropwise added through linkage control of a rotating plug and a lifting plug when the liquid formaldehyde is added, and the liquid formaldehyde is dropwise added dispersedly through a plurality of droppers, so that local reaction overheating caused by concentrated addition is avoided, side reactions are reduced, and the production efficiency is improved. The dropper penetrates through the heating cavity of the kettle cover with the special-shaped cavity, and the liquid formaldehyde is preheated before being dropwise added, so that the temperature of a mixed solution is prevented from being suddenly reduced by a low-temperature raw material, and the catalytic activity is ensured; the cylindrical cavity surface of the special-shaped cavity kettle cover extends into the kettle body, and heat is directly supplemented to the central area of a reaction system on the basis of outer layer heating, so that the temperature gradient is eliminated.

The invention discloses an internal-acid and external-alkali type organic-inorganic hybrid molecular sieve catalyst as well as a preparation method and application thereof, and belongs to the technical field of heterogeneous catalytic materials and chemical processes. According to the catalyst, a hydrogen type Beta molecular sieve is used as an acidic inner core, polyvinylpyrrolidone (PVP) is used as an organic shell, and a unique inner-acid outer-alkali structure is formed. The preparation method comprises the following steps: hydrothermally synthesizing a hydrogen type Beta molecular sieve with a specific silica-alumina ratio, and then coating PVP through surface adsorption. The catalyst is used for catalyzing the condensation of methylal and trioxymethylene under mild conditions (40-70 DEG C and normal pressure) to prepare polyoxymethylene dimethyl ethers (DMMn). The PVP shell covers acidic sites on the outer surface of the molecular sieve to form an external neutral / weak base and internal strong acid microenvironment, so that the secondary side reaction of the product is effectively inhibited, the trioxymethylene conversion rate of more than 98% and the DMMn selectivity of more than 96% can be obtained in the reaction at 50 DEG C and normal pressure, the product distribution can be regulated and controlled, and the traditional Anderson-Schulz-Flory distribution limitation is broken through. The catalyst disclosed by the invention has the advantages of high activity, high selectivity, mild conditions and easiness in separation, and has a good industrial application prospect.

The invention provides a perfluoroethanone microcapsule and a preparation method thereof, and belongs to the technical field of fire extinguishing materials, the perfluoroethanone microcapsule comprises a core and a shell layer; the core comprises perfluorohexanone and fumed silica; the shell layer comprises isophorone diisocyanate, diethylenetriamine and a chlorine-containing monomer, and the isophorone diisocyanate, the diethylenetriamine and the chlorine-containing monomer are subjected to an interfacial polymerization reaction to form a polyurea-polyurethane hybrid network; the mass ratio of the shell to the core of the microcapsule is 1: (5-20); the anhydrous microcapsule core is constructed through an oil-in-oil type anhydrous interfacial polymerization system, so that the hydrolysis side reaction is fundamentally avoided, the microcapsule has higher stable encapsulation efficiency, and the reliability and long-term effectiveness of the product in the storage and use processes are ensured.

The invention belongs to the technical field of chemical synthesis, and particularly relates to a method for preparing 5-methylfurfural by using 2-methylfuran. The special solid acid catalyst is used for replacing traditional phosphorus oxychloride, hydrogen chloride and phosphorus-containing wastewater are eliminated from the source, and the sulfolane is used for replacing DMF (Dimethyl Formamide), so that solvent residues in the product are reduced. The solid catalyst SO4 < 2-> is modified to form a strong Bronsted acid site (-SO3H) which cooperates with Ce < 3 + > / Ce < 4 + > redox to inhibit carbon deposition, selectively activate 2-methylfuran alpha-C and inhibit side reactions, so that the selectivity and yield of a target product are improved. Na2CO3 neutralization is replaced by electrochemical neutralization, salt slag solid waste is eliminated, and environmental pollution is reduced. After the organic phase is dried and dewatered through a molecular sieve, most of the solvent is removed through rotary evaporation, and the residual crude product is subjected to centrifugal molecular distillation, so that unreacted raw materials and trace impurities are effectively removed, and the product purity is remarkably improved.

The invention discloses a catalyst for preparing trichlorosilane and a catalytic preparation method of trichlorosilane. The catalyst is prepared from the following components in percentage by mass: weighed copper nitrate, zinc nitrate, aluminum nitrate, lanthanum nitrate and the balance of a carrier, the preparation method comprises the following specific steps: S1, filling a catalyst; S2, purifying raw material gas; S3, reacting; and S4, separating and purifying a product, namely discharging a reacted gas product from an outlet of a reactor, and condensing through a condenser. In the prepared catalyst, the activity and selectivity of the catalyst are remarkably improved through the synergistic effect of the copper-zinc-aluminum composite oxide and the rare earth element lanthanum, the electronic structure and the surface acid-base property of the catalyst can be adjusted through doping of lanthanum, the reaction of silicon powder and hydrogen chloride is promoted, meanwhile, side reactions are inhibited, and the service life of the catalyst is prolonged. And the yield of trichlorosilane is improved.

The invention discloses an electrolyte for water system energy storage and a preparation method and application thereof, and belongs to the technical field of electrochemical energy storage, the electrolyte for water system energy storage comprises a mixed salt and a mixed solvent, the mixed salt comprises a metal salt and an organic salt; the mixed solvent comprises water and an aprotic organic solvent; the organic salt is trifluoromethanesulfonate containing imidazole cations. Through the ion-solvent synergistic effect, an anion-rich and water-poor double-electrode-layer structure is formed on an electrode interface, dendritic crystal growth and side reaction are remarkably inhibited, and meanwhile high ionic conductivity is kept. The aqueous battery prepared from the electrolyte has good cycling stability and excellent practical performance under the conditions of low N / P ratio and low current density.

The synthesis process comprises the following steps: (1) introducing inert gas into a reactor, adding a solvent, a Lewis acid catalyst and diphenyl ether, then dropwise adding an acyl chloride monomer solution, and synthesizing an intermediate M with a short-chain small molecular structure; (2) continuously dropwise adding an acyl chloride monomer solution into the reactor for reaction, and then adding an end-capping reagent for reaction; and (3) quenching, washing and drying the reaction product in the step (2) to obtain the product. Under the condition that only the Lewis acid is used as the catalyst, the one-pot method is adopted for synthesizing PEKK in two steps, side reactions can be reduced, meanwhile, the dosage of the catalyst is reduced, the production cost is reduced, the post-treatment process is simplified, and the obtained polyether ketone ketone is high in molecular weight and good in heat resistance and mechanical performance.

The application discloses a catalyst for preparing polyoxymethylene dimethyl ethers by directly oxidizing methanol, a preparation method and application thereof, and belongs to the field of catalyst preparation and application. The metal oxide and the acidic molecular sieve are effectively coupled to prepare a bifunctional composite catalyst with a core-shell structure, the composition and proportion of the metal oxide and the acidic molecular sieve are regulated, and high-selectivity synthesis of polyoxymethylene dimethyl ethers by directly oxidizing methanol is realized. The unique core-shell structure can effectively regulate the distance and distribution between the two types of active sites, significantly promote the gradual chain growth of methanol oxidation, and obviously inhibit the occurrence of side reactions such as methanol dehydration to dimethyl ether and deep methanol oxidation, so that the high-selectivity synthesis of polyoxymethylene dimethyl ethers by directly oxidizing methanol is realized. The catalyst preparation process is simple and easy to operate, and the one-step oxidation of methanol to prepare polyoxymethylene dimethyl ethers has the advantages of short flow, good atom economy and green process.

The invention discloses lithium sulfide, a two-step double decomposition preparation method and application of the lithium sulfide in an all-solid-state battery, and belongs to the technical field of solid-state batteries. According to the preparation method, a two-step decomposition synthesis technology is adopted, lithium carbonate and ammonium thiocyanate are used as raw materials, the raw materials are uniformly mixed and then placed in a high-temperature reactor, a step heating sintering procedure is completed in an inert gas atmosphere, and the purpose of fully decomposing and converting the raw materials is achieved by accurately controlling the temperature and the time; after a product is obtained through reaction, the high-purity lithium sulfide material is obtained after the product is cooled to the room temperature. The method for preparing the lithium sulfide is low in raw material cost, simple in reactant formula and free of side reaction in the reaction process, and the finally generated product is few in impurity, high in purity and good in crystallinity.

According to the heteroatom-doped carbon nanohorn catalyst and the preparation method and application thereof, doping elements are accurately introduced into a carbon nanohorn framework in the preparation process of the catalyst, a stable heterostructure is formed, two-dimensional adsorption and activation of O2 molecules on the surface of an electrode are effectively enhanced, a two-electron reduction path is remarkably promoted, and the heteroatom-doped carbon nanohorn catalyst is prepared. The four-electron reduction side reaction is inhibited, the H2O2 selectivity and the oxygen reduction reaction (ORR) activity are enhanced, and the H2O2 yield and the Faraday efficiency are remarkably improved. Meanwhile, the heteroatom-doped carbon nanohorn catalyst has high electrochemical stability in a chloride ion-containing system, shows excellent stability and corrosion resistance under a natural seawater condition, and is suitable for long-time continuous operation.

The invention relates to the technical field of organic synthetic chemistry, in particular to a preparation method of ethyl 2-n-butyl acetoacetate, which comprises the following specific steps: S1, preparation of a composite solid base catalyst, S2, synthesis of ethyl 2-n-butyl acetoacetate, S3, post-treatment of a reaction solution, and S4, separation and purification of a product. The preparation method has the following beneficial effects that the magnesium-aluminum composite oxide is used as a carrier, and the composite solid base catalyst loaded with potassium and lanthanum has relatively high catalytic activity and selectivity; the magnesium-aluminum composite oxide carrier has a relatively large specific surface area and rich alkaline sites, so that a good catalytic environment is provided for the reaction; as a main active component, potassium ions can effectively activate alpha-active methylene of ethyl acetoacetate and promote formation of negative ion intermediates; the introduction of lanthanum ions can adjust the electronic structure of the catalyst, enhance the stability of the active center and inhibit the occurrence of side reactions.

The application discloses an improved electrolytic synthesis method of 3,6-dichloropicolinic acid, which comprises the following steps: adopting a diaphragm electrolytic cell, taking an aqueous solution containing 3,4,5,6-tetrachloropicolinic acid and a certain flow of CO2 gas as a cathode liquid, taking an aqueous solution of alkali metal hydroxide as an anode liquid, taking silver as a cathode, and taking a nickel-based material as an anode to carry out an electrolytic reaction, and obtaining 3,6-dichloropicolinic acid after the electrolytic reaction is completed. In the electrolytic process, the anode is separated from the cathode, so that corrosion is avoided; meanwhile, the CO2 gas is introduced to effectively control the occurrence of a hydroxylation side reaction, the molar yield of a hydroxyl byproduct is reduced from 20% to 35% to 2% to 8%, the molar yield of 3,6-dichloropicolinic acid is increased from 45% to 50% to above 80%, and the highest can reach 92.2%.

The invention discloses a catalyst for preparing cyclohexanone by cyclohexanol dehydrogenation coupled phenol hydrogenation, the catalyst has a composite metal hydrotalcite structure, the metal components comprise ruthenium, magnesium and aluminum, the metal components are uniformly dispersed in hydrotalcite, and the ruthenium, the magnesium and the aluminum respectively account for 1-5wt%, 10-30wt% and 1-10wt% of the total mass of the catalyst. The acid-base property, the specific surface area and the pore structure of the catalyst are optimized by adjusting the ratio of magnesium to aluminum, so that the dispersion of ruthenium is improved, the interaction between ruthenium and a hydrotalcite carrier is increased, and the synergistic effect of all the element components enables active centers in cyclohexanol dehydrogenation, hydrogen transfer and phenol hydrogenation processes to be efficiently combined together, so that the catalytic activity of the catalyst is improved. Rich alkaline sites are generated in the catalyst, the dehydration side reaction of cyclohexanol can be effectively inhibited, meanwhile, the selectivity of cyclohexanone prepared through phenol hydrogenation is improved, it is ensured that the phenol hydrogenation reaction and the cyclohexanol dehydrogenation reaction can be effectively coupled, and cyclohexanone is efficiently prepared.

The invention discloses a sodium metavanadate-based catalyst activity gradient regulation and regeneration system and method, and relates to the technical field of industrial catalyst regeneration, the sodium metavanadate-based catalyst is of a unique layered structure, the sodium metavanadate-based catalyst comprises an outer layer, a middle layer and an inner layer from the surface to the interior in sequence, and active components and doping elements of all the layers are different; the outer layer is doped with high-content sodium metavanadate and manganese oxide, reactant molecules can be quickly adsorbed and activated in the initial stage of the reaction, the manganese oxide can provide additional active sites, reduce reaction activation energy and promote quick start of the reaction, and the middle layer is doped with a proper amount of sodium metavanadate and cerium oxide, so that the reaction is more stable in the process of the reaction. The cerium oxide can adjust migration and conversion of oxygen species on the surface of the catalyst, optimize the reaction path, improve the selectivity of a target product and reduce side reactions, the inner layer is doped with the low-content sodium metavanadate and tungsten oxide, and the structural stability of the catalyst under high-temperature and long-time reaction is maintained by means of the high stability of the tungsten oxide.

The invention discloses a micro-channel continuous reaction device applied to gas-liquid oxidation reaction. The micro-channel continuous reaction device comprises a feeding system, a micro-channel reaction module, a temperature control system, a product collection system and a control regulation system, the feeding system conveys a gas raw material and a liquid raw material into the micro-channel reaction module; the micro-channel reaction module comprises three or more micro-channel units which are connected in series, and each micro-channel unit comprises a plurality of gas-liquid mixers and a plurality of enhanced mixing reactors; the temperature control system is used for accurately controlling the reaction temperature; the product collecting system is used for separating and collecting reaction products; and the control adjusting system is used for monitoring and adjusting reaction conditions in real time. According to the invention, efficient mixing and uniform distribution of gas and liquid phases can be realized, the reaction efficiency is remarkably improved, side reactions are reduced, real-time monitoring and adjustment of reaction conditions are realized, and the operation stability and safety are improved.

The invention discloses a hyperbranched polyether branching agent with an adjustable structure and a preparation method and application thereof.According to the branching agent, 3-butene-1-alcohol serves as an initiator, a hyperbranched skeleton is constructed through anion ring-opening polymerization reaction and diglycidyl ether, then esterification and end capping are conducted through anhydride, and the hyperbranched polyether branching agent with the adjustable structure is obtained. The tail end of the hyperbranched polyether contains vinyl double bonds, and the ester group structure of the hyperbranched polyether can be regulated and controlled. Different diepoxy compounds are selected to control a main chain structure, and different anhydrides are used for regulating and controlling the chemical composition of branched chains, so that accurate design of molecular weight, polarity and number of functional groups of the branching agent is realized. The branching agent has excellent dissolvability in common organic solvents, and solves the problem of poor dissolvability of the traditional polydiene branching agent. When the star-shaped branched butyl rubber is applied to the synthesis of star-shaped branched butyl rubber, the distribution and number of branched points can be accurately regulated and controlled, the weight-average molecular weight and molecular weight distribution index of the rubber are remarkably improved, and the side reaction of gel is avoided.

The invention provides a preparation method of dicapryl carbonate, belongs to the field of preparation of dicapryl carbonate, and can solve the problems of unstable reaction system, low raw material conversion rate, low catalyst efficiency, poor phase contact effect, many side reactions, low product purity and poor quality in the existing preparation method of dicapryl carbonate. The preparation method of dicapryl carbonate comprises the following steps: fully mixing n-caprylic alcohol, a basic catalyst and a cosolvent, continuously dropwise adding low-grade dialkyl carbonate into the mixed solution for 5-10 hours through a liquid material distributor, carrying out ester exchange reaction, continuously extracting low-boiling-point substances, controlling the reflux quantity, and carrying out reduced pressure distillation to obtain the dicapryl carbonate. The method comprises the following steps: adding a cosolvent into a reaction solution, enabling the cosolvent with an initial addition amount to always exist in the reaction solution, after the reaction is finished, dealcoholizing by reduced pressure distillation, and removing impurities by washing to obtain a crude product of dioctyl carbonate, and rectifying to obtain a dioctyl carbonate product. The preparation method is high in raw material conversion rate and high in product yield, and the purity of the obtained product is gt; the content of impurities is low, and the method can be applied to preparation of cosmetics.

The invention discloses a copper-based catalyst for preparing acetaldehyde through ethanol dehydrogenation as well as a preparation method and application of the copper-based catalyst. The preparation method comprises the following steps: S1, carrying out alkalization treatment on protic mordenite in a strong alkali solution to increase the number of surface hydroxyl groups of the protic mordenite; and S2, adding the mordenite obtained in the step S1 into a copper salt solution to load copper ions, and then sequentially carrying out low-temperature drying shaping and medium-temperature activation stages to obtain the copper-based catalyst with networked Cu-OH-Si-O bonds on the surface. Through the synergistic effect of alkali liquor regulation and control and staged oxygen roasting, the dispersity and stability of a Cu active center in the catalyst are improved, the acetaldehyde selectivity of the reaction of preparing acetaldehyde through ethanol dehydrogenation is also improved, and side reactions are inhibited. Carrying out heat treatment regeneration on the inactivated copper-based catalyst in an oxygen-containing atmosphere; and after regeneration, the networked Cu-OH-Si-O bond on the surface of the copper-based catalyst is reconstructed.