315 results about "Reactive site" patented 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 discloses a zinc-sulfur co-doped ZIF-67 derivative composite material as well as a preparation method and application thereof, and belongs to the technical field of advanced oxidation. The composite material is prepared through a coordination-substitution-calcination integrated process. The preparation method comprises the following steps: firstly, mixing a cobalt source and an organic ligand in methanol, and introducing a sulfur source to form a cobalt-based precursor; and drying, grinding with a zinc source, and calcining in an inert atmosphere. According to the method, stable cobalt active sites are replaced by isocrystals of zinc, sulfur doping promotes cobalt and peroxymonosulfate to form a weak oxidizing intermediate, and efficient and high-selectivity degradation of organic pollutants is achieved under the condition that a strong free radical path is not needed. The material is stable in structure and high in water quality interference resistance, is suitable for catalyzing peroxymonosulfate to degrade organic pollutants in a water body, and particularly has remarkable advantages in a complex water body.

The invention provides a monatomic cobalt-based composite catalyst, a preparation method of the monatomic cobalt-based composite catalyst and application of the monatomic cobalt-based composite catalyst to degradation of antibiotics by activating peroxymonosulfate, and belongs to the technical field of advanced oxidation. The method comprises the following steps: mixing biomass powder and water to obtain a biochar suspension, adding cobalt nitrate hexahydrate into the biochar suspension, centrifuging the mixed solution, collecting residues, and drying to obtain a sample; and pyrolyzing the sample in a protective gas atmosphere, taking out, cooling, washing, and drying to obtain the monatomic cobalt-based composite catalyst. The cobalt-based catalyst prepared by the invention has high specific surface area, abundant pore structures and a large number of active sites, and is beneficial to activation of PMS and degradation of pollutants; the cobalt-based composite catalyst prepared by the method is used for activating peroxymonosulfate to degrade tetracycline, and the removal rate of tetracycline in a solution is greater than 99% after reaction is carried out for 20 minutes under a dark condition.

The invention discloses a preparation method and application of a catalyst based on pyridine ionic liquid, and belongs to the technical field of catalyst preparation. According to the invention, a hydrolysis reaction of a silane coupling agent is utilized to prepare a silicon oxide nanotube containing a pyridine unit, and then a quaternization reaction is carried out to obtain the catalyst based on the pyridine ionic liquid. The catalyst has a high specific surface area and a rich pore channel structure, exposure of active sites and contact of the active sites and reactants are facilitated, and the catalytic rate is increased. Meanwhile, the silicon oxide nanotube contains hydroxyl, and can cooperate with a pyridine ionic liquid site to catalyze a carbon dioxide cycloaddition reaction. The obtained catalyst can catalyze the reaction of carbon dioxide and an epoxy compound to prepare cyclic carbonate under solvent-free and metal-free conditions, and the catalyst is easy to recover and simple in product purification, and has a good application prospect.

The invention discloses a copper-cobalt bimetallic catalyst and a preparation method and application thereof. The preparation method comprises the following steps: mixing ZIF-67, a copper source and a solvent, adjusting the pH value to 7.0, stirring, standing, centrifuging, washing and drying to obtain ZIF-67 adsorbed with copper ions, and calcining to obtain the copper-cobalt bimetallic catalyst. Compared with a conventional cobalt-based bimetallic catalyst, the copper-cobalt bimetallic catalyst prepared by the invention has the advantages of large specific surface area, multiple catalytic active sites, high catalytic activity, good structural stability and the like, is a novel catalyst with a novel structure and excellent performance, can efficiently activate peracetic acid and is used for degrading antibiotics; the method can realize deep oxidative degradation of various antibiotics in different water bodies, has the advantages of high reaction system activation rate, high degradation efficiency, wide pH application range, good reusability, low metal leaching amount, no secondary pollution and the like, and is high in use value and good in application prospect.

The invention relates to the technical field of metal organic framework materials (MOF) and isotope separation, in particular to a functionalized metal organic framework material for water / heavy water separation and a preparation method and application thereof. The metal organic framework material is a porous crystal material which is formed by coordination self-assembly of metal ions and V-shaped organic ligands and has a periodic network structure; the V-shaped organic ligand is a V-shaped dicarboxylic acid organic ligand modified by an oxygen-containing functional group designed through topological functionalization. According to the metal organic framework material, through topological functional design of a V-shaped organic ligand, a space confinement channel and a high-density oxygen active site are integrated in the same MOF material, and an ideal model system is provided for identification of water isotopes; according to the metal organic framework material, the framework structure flexibility, the pore channel confinement effect and the molecular recognition capability can be synergistically regulated and controlled, so that efficient recognition and separation of water / heavy water are realized.

The invention discloses a preparation method of a sulfonic acid type covalent organic framework material and a preparation method of 5-hydroxymethylfurfural. The material is prepared by carrying out covalent condensation reaction on a monomer containing a sulfonic acid group precursor and a connecting ligand of a skeleton through a hot solvent method, and the catalyst has the characteristics of high crystallinity, large specific surface area, ordered pore structure, high sulfonic acid group density and uniform distribution. The preparation method is simple, convenient, efficient, mild in condition and high in yield. Compared with a traditional lewis acid catalyst for preparing 5-hydroxymethylfurfural through fructose dehydration, the material has the advantages of being uniform and adjustable in porosity, higher in active site, capable of promoting fructose hydrolysis and the like, efficient conversion can be achieved, side reactions and product transition polymerization are inhibited, and better industrialization prospects are shown.

The invention relates to an A-site high-entropy double perovskite anode material and a preparation method and application thereof. The chemical general formula of the anode material is (Ln < 1 > < 0.2 > Ln < 2 > < 0.2 > Ln < 3 > < 0.2 > Ln < 4 > < 0.2 > Ln < 5 > < 0.2 >) A 'B2O5 + delta (wherein delta is greater than or equal to 0 and less than or equal to 1). Wherein Ln1 to Ln5 are five different lanthanide rare earth elements and jointly occupy the A site, and the A site elements are any five of Sm, Pr, Nd, La, Gd, Eu, Er, Dy, Te, Yb, Y and Sc; the A'site is composed of any two elements of Ba, Sr and Ca; and the B site is Co. According to the invention, the double perovskite structure can be effectively stabilized, the number of catalytic active sites of an OER reaction is increased, the TEC of a cathode is effectively reduced, the electro-catalysis ORR reaction activity is increased, the performance of hydrogen production by electrolysis of water of a single cell is improved, and the output stability of the cell is effectively enhanced.

The invention relates to the technical field of medicines, in particular to a preparation method of semeglutide, which comprises the following steps: by optimizing a coupling sequence, firstly connecting a main peptide chain compound 1 with a side chain compound 5 without carboxyl protection, and then performing subsequent coupling with a dipeptide structure compound 6 with high steric hindrance, thereby obtaining the semeglutide. The problem of excessive modification caused by coexistence of a plurality of active sites in a traditional route is effectively avoided, especially for coupling difficulty brought by the structure of a compound 6, the types of a condensation reagent and a side-chain compound 5 are optimized, dipeptide carboxyl of the compound 5 is remarkably activated, amido bonds can be efficiently formed by the compound 5 and a compound 2 under the mild condition, and the compound 6 can be efficiently synthesized. In the path of synthesizing the compound 3 from the compound 1, one-pot operation is realized, and the reaction liquid in each step can be used for the next step without refining, so that the reaction time and the consumption of raw materials are reduced, and the connection efficiency and selectivity of key steps are greatly improved.

The invention provides a preparation method of glycine, which comprises the following steps: preparation of a supported catalyst: dissolving an active component precursor in water, sequentially adding a catalyst carrier and a sodium hydroxide solution, uniformly mixing, and drying to obtain the supported catalyst; 2, mixing monoethanolamine with water, adjusting the pH value to be alkaline, adding the supported catalyst in the step 1, reacting, and filtering after the reaction to obtain a glycinate solution; and acidifying the glycine salt solution by using a hydrochloric acid solution, and performing crystallization separation to obtain glycine. A metal organic framework catalyst is introduced, the specific surface area reaches up to 6000 m < 2 > / g or above, the porosity exceeds 80%, meanwhile, the high mechanical strength is achieved, the evenly-distributed pore channel structure can effectively promote adsorption and diffusion of reactant molecules, an active precursor can be efficiently loaded on MOF active sites in the scheme, and the catalyst has the good application prospect. And in the catalysis process, the structure is stable and is not easy to damage, so that the catalysis efficiency is remarkably improved, the yield and purity of glycine are further improved, and the carrier can be repeatedly used.

The application provides a Sn-doped Fe-N-C catalyst, a preparation method and application thereof. The catalyst comprises a carrier and Sn atoms and Fe atoms supported on the carrier, and the carrier is an N-doped carbon material. The application dopes the p-block metal Sn with stronger electronegativity into the Fe-N-C catalyst, forms an electron-withdrawing environment around the FeN4 site, reduces the electronegativity of the FeN4 site, and weakens the adsorption strength of the FeN4 site on the oxygen reduction intermediate. Meanwhile, the metal Sn is weaker in reactivity with hydrogen peroxide produced by the reaction of oxygen via a two-electron process than Fe, reduces the concentration of free radicals produced by the reaction, improves the stability of the carrier and active sites, and can effectively prevent the shedding of Fe. The application uses the catalyst as a cathode catalyst of a proton exchange membrane fuel cell, is low in cost, and can simultaneously meet the requirements of high catalytic activity and good stability.

This invention relates to the field of catalyst technology, and discloses an inorganic-organic composite catalyst and its application, as well as a method for synthesizing acryloyloxyethyltrimethylammonium chloride. The catalyst preparation method includes: reacting a hydrolyzed siloxane coupling agent with titanium tetrachloride at a pH value less than or equal to 1.5. The hydrolyzed siloxane coupling agent is R-Si(OH)3, where R is a C8-C20 alkyl group, and the molar ratio of the hydrolyzed siloxane coupling agent to titanium tetrachloride is 0.07-0.15:1. This catalyst ensures synergistic effects of solubility and active sites, and exhibits high catalytic performance even at low dosages. In the synthesis of acryloyloxyethyltrimethylammonium chloride, it effectively improves the reaction efficiency and selectivity of acryloyloxyethyltrimethylammonium chloride, further increasing the yield and purity of acryloyloxyethyltrimethylammonium chloride.

The invention discloses a methane dry reforming catalyst and a preparation method thereof, and belongs to the technical field of catalysts.The catalyst is composed of 480 parts to 600 parts of Fe2O3, 60 parts to 75 parts of NiO, 1020 parts to 1530 parts of Al2O3, 16.2 parts to 82.5 parts of La2O3 and 9 parts to 18 parts of Gd2O3, and the catalyst is of an integral aerogel structure with a honeycomb-shaped or latticed macroscopic morphology; the preparation method comprises the following steps: S1, preparing a precursor solution; s2, adding a gel accelerant; s3, carrying out integral gel forming; s4, aging the wet gel; s5, solvent replacement; s6, performing supercritical drying; s7, calcining; according to the invention, active site design, a structure stabilization strategy and material form innovation are closely combined, and the prepared monolithic aerogel oxygen carrier not only shows a high CH4 / CO2 conversion rate and an ideal H2 / CO ratio, but also has excellent cycle stability and extremely low bed pressure drop; the core problems that in the prior art, the activation capacity and the carbon removal capacity are not matched, the high-temperature cycling stability is poor, and the engineering applicability of a powder material is limited are effectively solved.

The invention discloses a preparation method and system of a modified electrode material, and the method comprises the steps: an electrode material moves into a modification tank, the modification tank contains a modification solution with continuously changing concentration, and the electrode material is always soaked in the modification solution when passing through the modification tank; after leaving the modification tank, the electrode material is cleaned, dried and subjected to heat treatment, and the modified electrode material with continuous electrochemical activity change is obtained. According to the invention, by controlling the continuous change of the reaction active sites on the surface of the electrode material, the electrochemical activity of the reaction sites is fully utilized, the electrochemical activity change is concentrated on the same electrode material, and the tedious process caused by splicing of multiple sections of electrodes is also avoided.

The application provides a preparation method of a large-size tungsten-doped NiFe nanowire electrocatalyst, wherein the foam nickel is immersed in a corrosion solution containing Fe and W for 3-15 minutes to obtain a W-doped NiFe catalyst. The nanometer structure of the catalyst is an ordered nanowire with a diameter of 40-60 nm, and there is no agglomeration phenomenon, which is beneficial to the exposure of active sites and the release of oxygen, and the dense structure can improve the stability of the catalyst. When the W-NiFe catalyst is applied to an oxygen evolution reaction, the overpotential is only 143.7 mV when the current density is 10 mA cm ‑2 , and the catalyst can be stably operated for 150 hours under a current density of 500 mA cm ‑2 . The catalytic performance and stability of the catalyst are superior to those of a noble metal IrO2.

The application provides a Pt-based catalyst with (1x2)-(110) surface structure for catalyzing CO oxidation and a preparation method thereof. The preparation method of the catalyst is as follows: an oxide carrier and a platinum source are ground and loaded, and after heat treatment under a specific atmosphere, Pt-carrier powder is obtained; then the Pt-carrier powder is calcined with a mixed gas of CO and O2 at a certain temperature for a certain time, so that a Pt-based catalyst with Pt surface with (1x2) structure for catalyzing CO oxidation is prepared in situ. The Pt-based catalyst has the following characteristics: the (1x2) structure of the (110) surface of Pt nanoparticles changes the gas adsorption behavior, and establishes double active sites respectively beneficial to adsorption of O2 and desorption of CO, so that the problem of 'CO poisoning' in the Pt catalytic reaction can be significantly relieved during catalytic oxidation of CO. Compared with other catalysts with other structures, the Pt-based catalyst with the (1x2) special structure has more excellent CO catalytic oxidation activity, and has more practical application value.

The invention belongs to the technical field of high polymer materials, and particularly discloses glycidyl ester type epoxy resin and a preparation method thereof, the preparation method comprises the following steps: (1) melting polymerized rosin, adding a first catalyst, maleic anhydride, methacrylic acid and hydroxyl-terminated hyperbranched polyester, and reacting to obtain a precursor; and (2) adding bisphenol A epoxy resin and a second catalyst into the precursor, and reacting to obtain the glycidyl ester type epoxy resin. According to the invention, maleic anhydride, methacrylic acid, hydroxyl-terminated hyperbranched polyester and bisphenol A epoxy resin are combined; the three-dimensional synergistic enhancement of rigidity-flexibility-branching is realized, the proportion of rigid and flexible chain segments in a molecular structure is effectively coordinated, reaction active sites and crosslinking density are effectively improved, more reaction active sites and reaction activity are provided, and the mechanical property of a product is effectively improved.

The present application relates to the technical field of catalytic hydrogenation reaction, and discloses a preparation method and application of an organic phosphine shell modified nanocatalyst, which comprises the following steps: adding a carbon carrier in an alcohol solvent and ultrasonic dispersion, then adding a chloroplatinic acid containing alcohol solution, and stirring at 0-15 DEG C; subsequently, an organic phosphine containing alcohol solution and a reducing agent are added, and the stirring is continued; finally, rotary evaporation is carried out, and drying is performed to obtain the nanocatalyst; the nanocatalyst is a platinum catalyst with a core-shell structure loaded on the surface of the carbon carrier. By introducing the organic phosphine ligand to the surface of the nanometer platinum particles, the core-shell structure nanoparticles with a flexible organic phosphine ligand modified shell are constructed, the adsorption and desorption strength and configuration of the active site electronic structure, the reaction microenvironment, the reactants and the intermediate state of the reaction interface are regulated, and the selective and efficient hydrogenation of the aromatic hydrocarbon containing nitro or carbon-carbon double bond is realized.

The present application relates to the technical field of non-noble metal catalysts, and provides a sulfur-doped cobalt-based material with a core-shell porous structure, which has Co nanoparticles as an inner core, and a porous carbon layer containing Co9S8 coated on the surface of the Co nanoparticles. The present application significantly enhances the catalytic capacity of the material by regulating the micro-morphology and surface active site composition and structure of the material through sulfur doping. On the one hand, the metal sulfide obtained by S doping improves the electrical conductivity of the catalyst, and on the other hand, the S element can regulate the microstructure and morphology of the material due to its strong reducing effect, so that S doping is beneficial to promoting the exposure of active sites and the diffusion of target molecule, thereby significantly enhancing the oxygen molecule activation efficiency and improving the benzyl alcohol oxidation activity and selectivity.

This invention discloses a method for preparing a Bi3O4Br catalyst for the efficient degradation of tetracycline, comprising the following steps: S1, mixing bismuth nitrate and potassium bromide in an aqueous solution at room temperature, stirring, and filtering after the reaction to obtain a precipitate; S2, washing and drying the obtained precipitate to obtain a BiOBr precursor; S3, placing the obtained BiOBr precursor in a sodium hydroxide solution of a certain concentration and reacting at a certain temperature to obtain the Bi3O4Br catalyst. Experimental results show that the Bi3O4Br catalyst has a larger specific surface area and more photocatalytic active sites than pure Bi3O4Br, and has a higher oxygen vacancy (OV) concentration, exhibiting high catalytic activity in the photocatalytic degradation of tetracycline. This photocatalyst has broad practical value and application prospects.

The invention discloses a preparation method and application of a Beta molecular sieve catalyst rich in outer surface B acid, and solves the technical problem that the existing efficient catalyst is unstable in structure. The preparation method comprises the following steps: synthesizing the H-Beta carrier rich in the outer surface B acid: drying Beta zeolite raw powder without removing a template agent, then carrying out ion exchange for 2 hours by using an NH4Cl aqueous solution, washing a solid with water, drying, repeating the ion exchange process, and roasting the obtained ion exchange solid at 550 DEG C for 4 hours to obtain the H-Beta carrier rich in the outer surface B acid; and preparing the supported bifunctional catalyst: loading the metal Ir onto the H-Beta carrier rich in the B acid on the outer surface by an equivalent impregnation method. The Beta molecular sieve disclosed by the invention is rich in outer surface B acid, is used for a catalytic reaction for synthesizing high-density endothermic aviation fuel by converting polycycloalkane, provides higher reaction active site density and promotes diffusion of macromolecular cycloalkane.

The invention relates to the field of catalysts, in particular to a multi-scale microporous catalyst and a preparation method thereof.Firstly, diffusion and mass transfer of reactants and products are greatly accelerated through a through multi-stage pore network of the catalyst, the exposure degree of active sites is remarkably increased, and therefore the catalytic efficiency is improved; secondly, according to the system, the pore structure and the material composition can be optimized and combined according to the characteristics of different catalytic reactions, such as reactant sizes, reaction media and conditions, so that the system can be widely adapted to various reaction types such as a gas state and a liquid state, and covers most of catalytic scenes; furthermore, various preparation methods can be flexibly combined, especially the 3D printing technology is applied, so that design customization of multi-scale pores and the appearance of the catalyst is realized, and the preparation difficulty of a complex structure is greatly reduced; and finally, reasonable framework material selection and multistage pore design synergistically enhance the catalytic effect and inactivation resistance of the catalyst, so that the service life of the catalyst is prolonged compared with that of a traditional catalyst.

According to the preparation method, a proper amount of transition metal is introduced, the transition metal can be combined with precious metal, the use of the precious metal can be obviously reduced, synergistic interaction is achieved, the catalytic activity is improved, in addition, the ultrasonic-assisted cavitation effect is introduced, and polyhydric alcohol serves as a solvent and a reducing agent, so that the catalytic activity of the catalyst is improved. Under the synergistic effect of the stabilizer and the adjusting aid, agglomeration of nanoparticles can be effectively prevented, uniform reduction and nucleation of metal ions are greatly promoted, noble metal atoms and transition metal atoms are co-reduced to form atomic-scale dispersed alloy nano crystal nucleuses, and alloy nanoparticles with small and uniform particle sizes are formed; compared with the prior art, more specific surfaces can expose more active sites, the utilization rate of noble metal atoms can be increased, finally, after acid etching, a core-shell structure is formed through temperature programming reduction, the catalyst has better stability, the catalyst can still keep extremely high activity and stability after long-term operation, and the service life is remarkably prolonged.

The invention provides a method and equipment for screening an electrochemical alloy oxide catalyst. Comprising the following steps: utilizing a trained machine learning model to predict the difference of second adsorption free energy of each predicted active site on the surface of an alloy oxide to be detected to an electrochemical reaction intermediate; obtaining the first average current density and the uncertainty of the current density based on the difference of the second adsorption free energy of each predicted active site; determining a pre-selected alloy oxide by using the acquisition function to obtain a second average current density of the pre-selected alloy oxide; and under the condition that the difference value between the second average current density and the obtained maximum value of the first average current density is smaller than a preset value, determining that the pre-selected alloy oxide is the target alloy oxide catalyst for the electrochemical reaction. In this way, the electrochemical alloy oxide catalyst with high electrochemical catalytic activity can be rapidly screened out.

A high-load cobalt-based single-atom catalyst for oxygen reduction and its preparation method are disclosed, belonging to the field of electrocatalysis technology. This method utilizes the cage structure in ZnCo-ZIF to encapsulate nitrogen-rich metal molecules, followed by high-temperature carbonization under nitrogen conditions to obtain the catalyst. Benefiting from the separating effect of Zn metal nodes in ZIF and the spatial confinement effect of the ZIF cages, as well as the high nitrogen content in the guest molecule, a cobalt-based single-atom catalyst with a loading of 4.0 wt% was prepared. Furthermore, compared to traditional preparation methods, the catalyst prepared using a mixed solvent exhibits a small particle size, resulting in a high specific surface area that fully exposes the active sites. The large specific surface area allows for the full exposure of the high-load metal atom active sites, thus demonstrating excellent performance in the oxygen reduction reaction, with a half-wave potential of 0.88 V and a limiting current density of 6.0 mA·cm⁻¹ in 0.1 M KOH electrolyte. ‑2 .

The invention discloses a hydrophobic Ru nano-particle catalyst, a preparation method and application of the hydrophobic Ru nano-particle catalyst in bisphenol A hydrogenation reaction. The catalyst is prepared by dissolving a ruthenium salt precursor, mixing the ruthenium salt precursor with a surfactant containing nitrogen, phosphorus or sulfur, and reacting through a reducing agent in an inert atmosphere. The preparation method is simple and efficient, and reduction-modification coupling is realized in one step. Different from a traditional supported Ru catalyst, active sites of the carrier-free hydrophobic Ru nanoparticle catalyst are fully exposed, the particle size distribution uniformity of nanoparticles is excellent, and the dynamic light scattering PDI is smaller than or equal to 0.19. In the bisphenol A hydrogenation reaction, the raw material conversion rate reaches 95% or above, the selectivity of the target product hydrogenated bisphenol A reaches 95% or above, the conversion rate and the selective attenuation rate are both smaller than 5% after 5 cycles, and excellent cycle stability is achieved.

The application discloses a preparation method of a catalyst based on a pyridine ionic liquid and application thereof, and belongs to the technical field of catalyst preparation. The catalyst based on the pyridine ionic liquid is prepared by utilizing the hydrolysis reaction of a silane coupling agent to obtain silica nanotubes containing a pyridine unit, and then through a quaternary ammonium reaction. The catalyst has a high specific surface area and a rich pore structure, is favorable for exposure of active sites and contact of the active sites with reactants, and improves a catalytic rate. Meanwhile, the silica nanotubes contain hydroxyl groups, can synergistically catalyze a carbon dioxide cycloaddition reaction with pyridine ionic liquid sites, and can catalyze a reaction of carbon dioxide and an epoxide compound to prepare a cyclic carbonate under a solvent-free and metal-free condition. The catalyst is easy to recycle, product purification is simple, and the catalyst has a good application prospect.

The invention provides a cobalt-based microgel material as well as a preparation method and application thereof. The catalytic oxidation activity, stability and universality of the cobalt-based material to sulfite are effectively improved on the basis of the synergistic effect of constructing a microgel structure through reduction of sodium borohydride and regulating and controlling the boron loading amount to optimize catalytic active sites. The specific boron loading amount induced electron interaction between Co-O-B changes the electron cloud distribution and bonding environment of Co, so that the number and distribution of catalytic active sites are effectively regulated and controlled, and the pore structure of the microgel is stabilized, thereby promoting efficient contact between sulfite and the active sites; a stable microgel structure is formed through a liquid phase reduction-gelation process, agglomeration or loss of active components can be avoided, a proper amount of boron loading can prevent pore channel blockage, the problem of catalytic activity attenuation under high loading capacity can be effectively relieved, meanwhile, catalytic requirements of different sulfites are met, and the application range of the material is widened.

The invention belongs to the technical field of nano material preparation, and particularly relates to a Ru / CoNiFe-LDH composite catalyst and a preparation method and application thereof. The preparation method of the Ru / CoNiFe-LDH composite catalyst comprises the following steps: by taking CoNiFe layered double hydroxide as a carrier and Ru < 3 + > as an active component, mixing a Ru source solution and a CoNiFe layered double hydroxide solution under a stirring condition, so that the Ru < 3 + > is uniformly loaded on the surface of the carrier, and centrifugally drying to obtain a precursor; under the protective atmosphere, the precursor is roasted, and the Ru / CoNiFe-LDH composite catalyst is obtained. According to the Ru / CoNiFe-LDH composite catalyst, oxygen vacancies are provided through loading of Ru, the number of active sites is increased, accelerated transfer of electrons is promoted, and then the OER performance of the Ru / CoNiFe-LDH composite catalyst is improved.

The invention discloses an in-situ monitoring method for dynamic morphology and activity of a nitrate reduction reaction catalyst, and belongs to the technical field of electro-catalytic material characterization. And in combination with a modified electrolytic tank and a linkage strategy of'potential output-morphology scanning-activity detection ', in-situ co-positioning accurate monitoring of nanoscale morphology evolution and local activity distribution on the surface of the catalyst in the nitrate radical reduction reaction process is realized, and the method has high stability and compatibility and excellent dynamic quantitative characterization capability. According to the in-situ monitoring method developed by the invention, the technical bottleneck that the morphology and the activity are difficult to synchronously monitor by a traditional characterization technology is solved, and a brand-new dynamic analysis platform is provided for dynamic identification of active sites of a nitrate reduction reaction catalyst, analysis of a reaction mechanism and optimization of catalytic performance.