868 results about "Catalytic effect" patented technology

The invention relates to a catalyst for ethylene oxide ring-opening polymerization and a preparation method thereof, and belongs to the technical field of high polymer material synthesis, and the catalyst is a composite structure based on a silicon dioxide nanoparticle loaded bimetal organic complex; a modified nitrogen-containing polydentate ligand is prepared by adopting a special method, is coordinated with metal ions through covalent bonds and is loaded on silicon dioxide nanoparticles; by utilizing the high dispersity and stability of the silicon dioxide nanoparticles and the synergistic catalytic effect of the bimetal organic complex, the catalytic effect is effectively improved, the polymerization process is accelerated, the polymerization stability is enhanced, the polymerization molecular weight is improved, and the distribution is narrow.

The invention discloses a hydrogen evolution electrode for an AEM electrolytic cell cathode and a preparation method thereof, the electrode sequentially comprises a substrate net, a metal bottom layer and a catalyst layer, the substrate net is selected from a stainless steel net or a nickel net, the metal bottom layer is formed on the substrate net through physical vapor deposition, and the material is selected from Ni, Ti, alloys thereof or oxides thereof; the catalytic layer is deposited on the metal bottom layer through physical vapor deposition and sequentially comprises a catalytic bottom layer, a catalytic middle layer and a catalytic outer layer, and the porosity is gradually increased. The preparation method comprises the following steps: roughening the acid etching surface of a substrate net, forming a metal bottom layer on the substrate net through physical vapor deposition, sequentially forming a catalytic bottom layer, a catalytic middle layer and a catalytic outer layer on the surface of the metal bottom layer through physical vapor deposition to obtain a catalytic layer, and performing post-treatment on the catalytic layer through plasmas doped with elements to form a porous network structure. And the corrosion resistance and the catalytic effect of the AEM electrolytic cell cathode in an alkaline environment are greatly improved.

The invention belongs to the technical field of electro-catalysis and energy conversion, and provides a carbon skeleton loaded platinum monatomic-cobalt nanoparticle catalyst, a preparation method thereof and application in electro-catalysis hydrogen evolution, a ZIF-67-ZIF-8 precursor is prepared in an epitaxial growth mode, and the precursor is pyrolyzed to construct a carbon matrix containing cobalt nanoparticles; in the preparation process of ZIF-67-ZIF-8, the treatment duration of tannic acid is regulated and controlled, and the size of cobalt nanoparticles is accurately controlled; meanwhile, uniform N holes generated in the high-temperature pyrolysis process are beneficial to precise range limitation of PtN bonds, and finally the carbon skeleton loaded platinum monatomic-cobalt nanoparticle catalyst is constructed. The concentration of local protons around platinum sites is enriched through cobalt, and therefore adsorption of protons on platinum single atoms and generation of hydrogen are remarkably promoted. Due to the display of the bifunctional catalytic effect, the overall catalytic efficiency of the alkaline hydrogen evolution reaction is effectively improved. The catalyst shows excellent catalytic performance in alkaline hydrogen evolution reaction, and is expected to be widely applied to the water electrolysis hydrogen production technology.

The invention discloses a supported nickel catalyst for preparing 1, 3-propylene glycol through hydrogenation of 3-hydroxypropionaldehyde as well as a preparation method and application of the supported nickel catalyst, and relates to the technical field of catalysts. The modified long-chain multi-carbon inducer is used, and a special long-chain molecular structure and a branched chain group of the inducer can effectively and selectively adsorb and occupy a micropore impregnation site; the preparation method has the beneficial effects that more active component nickel species are obviously promoted to be dispersed in main reaction confinement spaces such as mesopores and macropores and interact with the carrier to form effective active sites, and active component steeping liquor is inhibited from entering micropore channels due to capillary action; the active site failure caused by agglomeration of nickel species in micropores in the subsequent drying and roasting process of the catalyst precursor is avoided, the efficient and directional reaction is ensured, the generation of by-products is greatly reduced, the pressure is relieved for the subsequent product rectification separation, and the final product purity is improved. The catalyst provided by the invention can still keep an excellent catalytic effect when the air speed of a 3-hydroxypropionaldehyde solution is increased to 6.5 h <-1 >.

The invention relates to a preparation method and application of a hydrothermal ammonolysis lignin carbon-based multi-metal catalyst. The Ni-N-C structure is constructed by a hydrothermal nitrogen doping method to enhance the synergistic effect of the catalytic active component and the lignin carbon-based carrier, and Zn is doped to regulate and control the electronic structure of Ni and effectively inhibit hydrogenolysis and methanation of carbon-carbon bonds in the reaction process, so that the catalytic activity of the catalyst and the selectivity of the product are improved. According to the catalyst obtained by the preparation method, the ethanol conversion rate can reach 69.4%, the yield of higher alcohols can reach 50.3%, the selectivity of gas byproducts is only 2.4%, the catalytic effect is good, and the problems that an existing traditional ethanol Guerbet coupling catalyst is low in ethanol conversion rate, tedious in synthesis process, poor in stability and the like can be effectively solved.

The invention relates to the technical field of electrocatalytic oxidation devices, and discloses an electroplating rinse sewage complex breaking electrocatalytic device based on titanium-based nano conductive ceramics, which comprises an oxidation pond and an acquisition module, the acquisition module acquires catalytic liquid information in real time, and the catalytic liquid information comprises components and state data of a catalytic liquid. And the catalysis module is responsible for treating a catalytic liquid and destroying a complex by utilizing an electro-catalysis reaction. The central control module analyzes complex components of a catalyst through a convolutional neural network (CNN) and a recurrent neural network (RNN), and dynamically adjusts electro-catalysis parameters on the basis of a fuzzy control algorithm in combination with historical data and real-time information so as to optimize the catalytic effect. And the early warning module monitors the changes of the catalytic liquid and the electro-catalysis parameters, judges whether early warning needs to be given out or not by comparing the changes with a preset threshold value, and takes corresponding measures according to the risk level. Through real-time data analysis and intelligent control, the accuracy and efficiency of the catalysis process are improved, and the safety and stability of the treatment process are ensured.

The utility model discloses a photoelectrocatalysis sewage treater which comprises a cylinder body, an ultraviolet lamp is installed at the bottom end of an inner cavity of the cylinder body in a sealing mode, a cleaning piece is arranged outside the ultraviolet lamp in a sleeved mode, the cleaning piece can rotate through a motor, the motor is installed in an inner cavity of a protective shell, and the protective shell is installed at the top end of the cylinder body. The cleaning piece can be driven to rotate by starting the motor, the outer wall of the ultraviolet lamp can be cleaned, the protective shell can be used for installing the motor and can protect the driving assembly, compared with the prior art, the outer wall of the ultraviolet lamp can be cleaned, and the ultraviolet lamp can be conveniently cleaned. Sediments are not easy to adhere, and the irradiation effect of the ultraviolet lamp is not easy to influence, so that the catalytic effect of the photocatalytic part is not influenced.

The invention discloses a method for degrading polystyrene (PS) plastic and upgrading and recycling the PS plastic into benzoic acid based on nano MnO2 photocatalytic ozonation, and belongs to the technical field of solid waste recycling. The method comprises the following steps: firstly, mixing PS plastic fragments with nano MnO2 and an organic solvent, then simultaneously introducing ozone into a reaction system at normal temperature and normal pressure, and irradiating with light. Through synergistic catalysis of light and ozone, molecular chains of the PS plastic can be efficiently and selectively broken and oxidized, and finally the PS plastic is directionally converted into benzoic acid with high additional value. After the reaction is finished, a benzoic acid product can be obtained through simple separation, concentration and purification steps. The method provided by the invention realizes high-valued recycling of the waste PS plastic under mild conditions, solves the problems of high energy consumption, complex products, easy generation of secondary pollution and the like in a traditional treatment method, and has the outstanding advantages of green process, efficient reaction, high product value and the like.

The invention belongs to the technical field of lignin depolymerization, and particularly relates to a selective fracture method of micromolecular mercaptan mediated lignin beta-O-4 connection. In an H-type electrolytic tank, an anode electrolytic tank takes a buffer solution as an electrolyte, a cathode electrolytic tank takes a lignin beta-O-4 model compound as a reaction substrate, and an acetonitrile / buffer solution mixed solution of small molecular mercaptan is taken as an electrolyte for electrochemical cracking reaction. Wherein a micromolecular mercaptan medium is used as a single electron transfer medium, and can efficiently and selectively break key C beta-O bonds in a lignin beta-O-4 model compound at normal temperature and normal pressure under the catalytic action of current to obtain corresponding phenol and ketone monomers, so that the problems that high temperature, high pressure and expensive catalysts are usually needed in depolymerization in a lignin reduction way are solved.

The invention relates to preparation and photocatalytic application of a three-component covalent organic framework photocatalyst. The invention aims to solve the problems of low visible light utilization rate, low efficiency of photocatalytic synthesis of hydrogen peroxide and complex synthesis process of a multi-component covalent organic framework material in the synthesis of a high-performance photocatalyst in the prior art. The method comprises the following steps: dispersing two reaction monomers into an organic solvent to form a mixed solution, adding a catalyst into the mixed solution, then adding the third monomer, carrying out ultrasonic dispersion, carrying out a heating reaction for a period of time, cooling to room temperature, and carrying out solid-liquid separation to obtain a solid; and carrying out solid separation, collecting the solid, washing and drying to obtain the three-component covalent organic framework material. The prepared TTBTP-1 three-component covalent organic framework photocatalytic material is high in crystallinity and good in catalytic effect and is superior to a two-component photocatalyst, the preparation method is simple, through the design thought that p-phenylenediamine is adopted as a linker to connect two monomers with different structures, the thought is broadened for the design of a novel COF structure and function, and the application prospect is broad. The method has important research significance.

The invention belongs to the technical field of carbon materials, and discloses coal-based porous carbon based on trace salt induction activation and a preparation method thereof. The preparation method of the coal-based porous carbon based on trace salt induced activation comprises the following steps: uniformly mixing Zhundong coal and trace salt to obtain a mixed product, heating the mixed product in an inert atmosphere and then keeping the temperature constant to obtain a carbonized product, and cooling the carbonized product to room temperature in an active atmosphere to obtain activated carbon, sequentially carrying out acid pickling and drying treatment on activated carbon to obtain coal-based porous carbon; the catalytic action of positive ions in trace active salt and the induction action of negative ions can be combined, so that the action effect of the trace salt is further improved, the activation rate is increased, the distribution of a pore structure is regulated and controlled, the specific surface area of the coal-based porous carbon is increased, and the pore structure is also improved.

The invention provides a PTFE modified membrane, a modification method thereof, a wastewater treatment system and a wastewater treatment method, the PTFE modified membrane is obtained by adding metal oxide catalyst particles into a PTFE polymer for modification, and the weight of the metal oxide catalyst particles accounts for 5-20% of the weight of the PTFE polymer; the diameter of the metal oxide catalyst particles is 10-100 nm; the pore-forming rate of the PTFE modified membrane is 53-62%, and the pore diameter range is 0.1-1 [mu] m. The metal oxide catalyst particles are added into the PTFE polymer of the hollow fiber membrane for modification to form the PTFE modified membrane, so that the gasification catalytic effect of ozone on the surface of the membrane material of the hollow fiber membrane module is improved, and full contact, mixing and net-effect removal of pollutants and ozone are realized; therefore, the pollutant removal rate and the quality of a product produced by wastewater treatment are improved; the technological process is simple, field application is convenient, and product performance is stable.

The invention relates to the field of distillation equipment, in particular to a novel distillation tower. The technical problems that in a traditional device, contact between a catalyst and a raw material is not sufficient, the catalytic effect is poor, the distillation efficiency is low, it is inconvenient for workers to intermittently add the raw material into a distillation cylinder, and continuous work is not convenient are solved. A novel distillation tower comprises a supporting frame, a distillation cylinder is fixedly connected to the supporting frame, the distillation cylinder is hollow, a liquid outlet valve is fixedly connected to the bottom of the distillation cylinder, and a heating frame is rotatably connected to the lower portion of the inner wall of the distillation cylinder. The contact frame is driven by the motor to rotate, the contact frame extrudes the limiting plate upwards, the through hole in the limiting plate moves upwards to enter the discharging pipe, raw materials can enter the distillation cylinder, the contact frame continues to rotate to be separated from the limiting plate, the limiting plate limits the raw materials again, intermittent discharging into the distillation cylinder can be facilitated, and continuous work is facilitated.

The invention discloses a preparation method and a dyeing process of 5, 5 '-dihydroxy-observation blue, and relates to the field of dye chemical industry. According to the preparation method of the 5, 5 '-dihydroxy-observation blue, provided by the invention, amino on the observation blue is converted into hydroxyl by utilizing the catalytic effect of the vanadium-based catalyst in an acid environment, the production of the 5, 5'-dihydroxy-observation blue can be realized through one-step reaction, the yield is up to 32.47% or above, and the obtained compound can be used as a blue direct dye and can be used for preparing blue dye. After being dyed, a fabric can present bright blue, the K / S value reaches 10 or above, and the fabric has excellent color fastness, and the color fastness to washing, the color fastness to soaping and the color fastness to wet rubbing all reach 4-5 levels.

The invention relates to a novel slow-gelation fast-curing polyurethane material, which is prepared from the following components in parts by mass: 52 to 58 parts of aromatic diisocyanate, 85 to 100 parts of polyether polyol, 0.1 to 0.3 part of composite catalyst and 0.3 to 0.6 part of cross-linking agent, the composite catalyst is formed by compounding a tertiary amine catalyst and an organic tin catalyst according to a mass ratio of 7: 5. According to the invention, the catalyst compounded by the tertiary amine catalyst and the organic tin catalyst in a specific proportion is introduced in the polyurethane synthesis process, so that the reaction has the advantage of controllable catalytic effect. The activity at the early stage of reaction is low, so that the gelation time is effectively prolonged, a mold can be fully filled with feed liquid, the injection molding period of a large and complex panoramic sunroof is well met, and the yield is improved; meanwhile, the curing speed in the later reaction period is high, and the production efficiency of products can be improved.

The invention discloses a Ni-based'bimetallic-alkali-acid 'multifunctional hydrotalcite catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalytic synthesis of fine chemicals. According to the invention, a Ni-N-MO-Al hydrotalcite precursor oxide (a main metal is Ni, a second metal N is one of Cr, Mn, Fe, Co or Cu, and M in an alkali metal oxide MO is one of Mg, Ca, Sr, Ba, Cd or Zn) with a layered porous structure is synthesized, and then the Ni-based'bimetal-alkali-acid 'multifunctional hydrotalcite catalyst is prepared through an efficient in-situ desolvation method. According to the method, the multi-center synergistic effect of the catalyst, including Ni-N bimetallic hydrogenation active sites, MO alkaline sites and Lewis acid sites of an Al framework, is fully utilized, and the target product dimethyl succinate is prepared with high selectivity under mild conditions through bimetallic-alkali-acid multi-site synergistic catalysis and strong metal carrier interaction.

The invention discloses a metalloporphyrin porous electro-catalytic material with a bcu topological network structure, a preparation method of the metalloporphyrin porous electro-catalytic material and application of the metalloporphyrin porous electro-catalytic material in electro-catalytic oxygen evolution. A quadrangular pyrenyl skeleton molecule with eight connecting nodes and a quadrangular porphyrin skeleton molecule with eight connecting nodes are adopted, an ordered and expanded double-interpenetrating three-dimensional bcu topological network framework material is obtained through [8 + 8] imine condensation, and metallization of a porphyrin unit is further realized through metal ion post-modification, so that the porphyrin unit is obtained. The metalloporphyrin porous electro-catalysis material is obtained; the material as a heterogeneous catalyst has more excellent mass transfer efficiency and more accessible catalytic sites, has a wide application prospect in the field of catalysis, and particularly has an ideal catalytic effect in an electro-catalysis oxygen evolution reaction; # imgabs0 #

The invention provides an MOF-based derivative composite photocatalyst as well as a preparation method and application thereof, and belongs to the technical field of photocatalysts. The MOF is quenched in the soluble metal salt solution after being calcined, the MOF derivative material formed through calcination can be rapidly cooled through quenching, a large number of defects are formed on the surface of the MOF derivative material, on one hand, the number of oxygen vacancies can be increased through the defects, and the oxygen vacancies are beneficial to electron transmission and improvement of the catalytic effect; on the other hand, the metal loading capacity can be improved, the binding force between the MOF derivative material and the metal is high, the MOF derivative material is not prone to falling off, and the photocatalyst has good stability. According to the method, metal ions can be promoted to be reduced to form metal simple substances or metal clusters through reduction treatment, and the metals can generate heat when being used as the photocatalyst, so that oxygen vacancies and the metals generate light-heat effect for concerted catalysis, and the degradation effect of the photocatalyst on antibiotics is further improved.

The invention belongs to the field of electrochemical gas sensors, and particularly relates to a phenol gas sensor based on quantum dots and a preparation method of the phenol gas sensor. The gas sensor comprises a quantum dot sensing film, polyphenol oxidase on the surface of the quantum dot sensing film and an enzyme stabilizing composite reagent covering the polyphenol oxidase, benzoquinone is formed on the basis that phenol is oxidized through molecular oxygen on the basis of the polyphenol oxidase, the enzyme-substrate efficient specific catalysis effect is achieved, and the content of the polyphenol oxidase in the gas sensor is increased. The polyphenol oxidase-based quantum dot phenol gas sensor is designed. The sensor is high in phenol gas detection specificity and sensitivity.

The invention discloses a multi-metal layered hydroxide catalytic material and a preparation method and application thereof, and belongs to the technical field of catalytic materials.The preparation method of the multi-metal layered hydroxide catalytic material comprises the following steps that a one-pot solvothermal method is adopted, foamed nickel is soaked in a mixed solution for hydro-thermal synthesis, and the multi-metal layered hydroxide catalytic material is obtained; the multi-metal layered hydroxide catalytic material is prepared; wherein the mixed solution comprises a surfactant, a solvent and at least two of a nickel source, an iron source and a cobalt source. The CO2 desorption rate of the MEA solution is jointly improved through the synergistic effect of multiple metals and the # imgabs0 # acid site provided by the periphery of the metal hydroxide main layer. Under the condition that the desorption temperature (oil bath pan temperature) is 120 DEG C, the highest CO2 desorption rate of the FeCo (1 / 5) material with the best catalytic effect is increased to 7.68 mmol / min, and compared with 4.78 mmol / min under the blank condition, the desorption rate of the FeCo (1 / 5) material is increased by 60.7%, and the CO2 desorption rate is remarkably increased.

The invention belongs to the technical field of ion exchange membranes, and relates to a bipolar membrane and a preparation method thereof.The bipolar membrane comprises a cation exchange membrane, an anion exchange membrane and a middle layer; the cation exchange membrane is sulfonated polysulfone; the anion exchange membrane is aminated chloromethyl polysulfone; and the middle layer is prepared by reacting an organic amine compound with vinyl and chloromethyl polysulfone. The substrates of the three layers of polymers of the bipolar membrane are all made of polysulfone materials, the swelling characteristics of the materials are consistent, the affinity among the three layers is appropriate due to the fact that the three layers are made of the same material, the affinity among the layers of the bipolar membrane is easy to be tight, meanwhile, the stability of the middle catalyst layer is enhanced through a cross-linking method, and the stability of the middle catalyst layer is improved. The loss of the catalytic effect is prevented; the technical problem that the middle layer is prone to loss or blistering is solved.

According to the epoxypropane production system and method with the high conversion rate and the high yield, the interior of the reactor is divided into the upper section and the lower section through the production system, the accurate feeding proportion of three materials is provided, and the mode of segmented control and distributed feeding is provided; propylene and most of hydrogen peroxide diluted by a solvent are added into a first reaction section at the bottom through a first-stage feeding distributor for reaction, and then a reaction mixed solution of the residual solvent and hydrogen peroxide is supplemented into a second reaction section through a second-stage feeding distributor, so that reaction materials are uniformly mixed for reaction; the problem that the temperature is too high and hydrogen peroxide is decomposed due to uneven mixing caused by one-time adding or non-distributed adding of materials is avoided, the conversion rate of the materials is increased, meanwhile, fins are arranged on the outer sides of the catalytic tubes, the heat exchange area is increased, reaction heat is discharged in time, hydrogen peroxide decomposition is avoided, and the catalytic effect is improved. The selectivity and the yield of the product epoxypropane are further improved.

The invention discloses a high-entropy spinel ferrite catalyst for efficiently degrading dyes and antibiotics as well as a preparation method and application of the high-entropy spinel ferrite catalyst. The Cu1 / 2Zn1 / 2Fe2 / 3Co2 / 3Ni2 / 3O4 (HEO-FNCCZ) high-entropy spinel ferrite catalyst is prepared by adopting a sol combustion method, the photocatalytic degradation performance of common dyes and antibiotics is evaluated by simulating visible light photocatalysis, and the reaction mechanism of photocatalytic degradation of methylene blue with the best effect is researched. The photocatalytic reaction is effectively promoted by utilizing the catalytic effect of the spinel ferrite, so that environment-friendly pollutant degradation is realized. According to the method, the production process is simple, various organic toxic and harmful substances are not introduced, the method is nontoxic and harmless in the use process, the recovery efficiency of the catalyst exceeds 95%, and the method has the characteristics of remarkable degradation effect and no secondary pollution; the preparation method only relates to the processes of dissolving, calcining, crushing and the like, and is extremely suitable for industrial batch production.

The invention discloses a method for preparing nano-copper particles from eucommia ulmoides extract and application of the nano-copper particles in a catalytic reduction reaction in the technical field of metal nano-materials, the eucommia ulmoides extract is adopted as a reducing agent, a bivalent copper salt solution is added, a reaction can be carried out in a water phase, and the nano-copper particles are generated. The raw materials are cheap and easy to obtain, the reaction conditions are easy to control, the process is simple, and the prepared nano-copper particles have good dispersity and show a good catalytic effect in the aspect of catalytic reduction of organic dye and nitrophenol.

The invention discloses a preparation method of a bifunctional heterojunction catalyst for AEM electrolyzed water. The method comprises the following steps: step 1, mixing multi-walled carbon nanotubes, deionized water, absolute ethyl alcohol and inorganic acid; step 2, putting the mixed solution in the step 1 into an ultrasonic machine to form a porous structure and more active adsorption sites; step 3, carrying out freeze drying treatment on the mixed solution treated in the step 2; step 4, mixing the dried multi-walled carbon nanotubes with acetylacetone salt, and uniformly grinding the mixed powder; and step 5, putting the powder obtained in the step 4 into a tubular furnace, and carrying out heat treatment in the atmosphere of H2 / Ar to obtain the PtFeCoNiMoZr / ZrO heterojunction catalyst. The catalyst has a remarkable catalytic effect on HER and OER reactions, and meanwhile, stable electrolysis which stably runs for 200 hours in an AEM electrolytic cell under the current density of 1200 mA / cm < 2 > is successfully realized.

A catalyst for an acylation reaction, and a preparation method therefor and the use thereof. The preparation method for the catalyst for an acylation reaction comprises the following steps: (1) adding a cation exchange resin to a 0.1-10 mol / L hydrochloric acid solution, performing an ultrasonic treatment for 1-60 min followed by filtration, washing same with water until the filtrate is neutral, and filtering same; and (2) adding the cation exchange resin, which is obtained after the treatment in step (1), to a chromatographic column, adding a 0.01-5 mol / L Lewis acid solution for leaching, filtering same, then washing same with water, and drying same to obtain a catalyst for an acylation reaction. The catalyst for an acylation reaction can efficiently achieve an acylation catalytic reaction of a naphthalene-containing compound and has a good catalytic effect, and the post-treatment is simple.

The invention discloses nanoscale simple substance Ni which is prepared by taking nickel chloride hexahydrate, sodium hydroxide and 1, 2-propylene glycol as raw materials and performing water bath heating reduction through a reducing agent hydrazine hydrate. The size of the obtained nanoscale simple substance Ni is 5-10 nm, and particles are uniformly dispersed and are stable in structure. MgH2 and the prepared nanoscale simple substance Ni are subjected to ball milling, and the magnesium hydride composite hydrogen storage material based on the nanoscale simple substance Ni as the catalyst, namely Ni / MgH2 for short, can be obtained. The initial dehydrogenation temperature of the obtained Ni / MgH2 hydrogen storage system is 195 DEG C; under the conditions that the dehydrogenation temperature is 325 DEG C and the dehydrogenation time is 500 seconds, the dehydrogenation amount is 6.5 wt%; under the conditions that the hydrogen absorption temperature is 150 DEG C and the hydrogen absorption time is 1000 seconds, the hydrogen absorption amount is 4.0 wt%. The prepared catalyst is used for catalyzing MgH2 reaction and has the characteristics of high activity, high selectivity and high stability. The preparation method disclosed by the invention is low in cost, simple in steps, relatively good in repeatability and easy for mass production, and the obtained elemental Ni has a good catalytic effect.

A method for catalytically synthesizing a single chiral 2-aryl-substituted nitrogen heterocyclic derivative by means of an imine reductase, and a use thereof. The method comprises: under the catalytic action of an imine reductase, converting a compound represented by formula II into a single chiral compound represented by formula I. In formulas I and II, each R is independently selected from hydrogen, fluorine, chlorine, bromine, C1-C6 alkyl, halogenated C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, cyano, nitro, or carboxyl; X is selected from -CH2- or -O-; and n is an integer selected between 0 and 6. The imine reductase is selected from any one of or a combination of at least two of the following amino acid sequences: (1) an amino acid sequence as shown in any one of SEQ ID NOs: 2, 4, 6, 7, or 10; and (2) an amino acid sequence having imine reductase activity and having at least 90% identity to the sequence as shown in any one of SEQ ID NOs: 2, 4, 6, 7, or 10.

The invention belongs to the technical field of reverse water gas shift, and discloses a method for catalyzing reverse water gas shift by magnetic induction, which comprises the following steps: tabletting and molding a magnetic catalyst and white carbon black to obtain a catalyst; a catalyst is placed in an induction coil area of induction heating equipment, mixed gas of CO2 and H2 is introduced, a reverse water-gas shift reaction is carried out, the reaction pressure is normal pressure, the alternating frequency is 50-300 KHz, and CO is produced. According to the invention, the charge-spin concerted catalysis reverse water-gas shift process of the catalyst is realized through the action of the magnetic field. The reverse water-gas shift reaction is a strong heat absorption process and needs a high reaction temperature, and the reverse water-gas shift catalyst used in the magnetic induction system has a heating effect and a catalytic effect at the same time and can achieve excellent performance at a low temperature. And the problems of high energy consumption, low energy utilization rate and non-uniform heating of the traditional catalytic reaction are avoided.

The invention discloses silver-copper alloy nanoparticles with a core-shell structure as well as a preparation method and application of the silver-copper alloy nanoparticles. The core of the core-shell structure silver-copper alloy nanoparticle is a silver-copper alloy nanoparticle, and the shell of the core-shell structure silver-copper alloy nanoparticle is a ZIF-8 coating layer. The preparation method of the silver-copper alloy nanoparticles with the core-shell structure comprises the following steps: 1) preparing the silver-copper alloy nanoparticles; (2) preparing surface modified silver-copper alloy nanoparticles; and 3) dispersing the surface-modified silver-copper alloy nanoparticles, zinc salt and 2-methylimidazole in methanol for reaction. The silver-copper alloy nano-particles with the core-shell structure have the advantages of rich active sites, good catalytic effect, high cycling stability, mild reaction conditions, simple preparation method and the like, can be used for carboxylation of terminal alkyne and CO2 to generate propiolic acid compounds and carboxylation of propargyl amine and CO2 to generate 2-oxazolidinone compounds; and the method has a very wide application prospect.