23results about How to "Fast mass transfer" patented technology

The invention discloses a porous ruthenium-based oxide as well as a preparation method and application thereof. Rich ruthenium metal site types and proportion regulation and control ranges are provided, the utilization efficiency of precious metal components is improved, and excellent oxygen evolution reaction catalytic activity is provided for the catalyst; transition metal or rare earth metal is doped to provide a more stable acid-resistant and high-potential structural framework for the catalyst, so that the working stability of the catalyst in an oxidation environment is improved; the loose porous catalyst structure is beneficial to rapid mass transfer of gas, structural damage caused by gassing is reduced, excessive oxidation dissolution of ruthenium is avoided, and the structural stability of the catalyst is improved. The porous ruthenium-based oxide OER catalyst with high catalytic activity and a stable structure can be prepared by the method, and is suitable for application scenes of an anode reaction catalyst in a proton membrane electrolytic cell and other oxygen evolution reaction catalysis.

The invention relates to the technical field of preparation methods of biomimetic enzyme reactors, and particularly discloses a preparation method and application of a biomimetic enzyme aerogel reactor, and the preparation method specifically comprises the following steps: step S1, firstly preparing titanium dioxide nanofibers (TiNFs) through solvent heat treatment; step S2, carrying out freeze casting and vacuum drying on an aqueous dispersion containing titanium dioxide nanofibers (TiNFs), chitosan methacrylate (CSMA) and a cross-linking agent to obtain a bionic C / TiNFs aerogel reactor with vertically arranged channels; step S3, carrying out polymerization and modification on glycidyl methacrylate (GMA), methacryloylethyl sulfobetaine (SBMA) and an N, N '-methylene bisacrylamide (MBA) cross-linking agent on a skeleton of the simulated gas gel reactor; and step S4, covalently immobilizing tannase in the bionic gas gel reactor under a mild condition, so as to obtain the bionic tannase-pGSC / TiNFs enzyme reactor. The bionic tannase-pGSC / TiNFs enzyme reactor disclosed by the invention is composed of TiNFs, CSMA (Carboxymethyl Methacrylate), polyglycidyl methacrylate (PGMA), polymethylacryloyl ethyl sulphobetaine (PSBMA) and immobilized tannase, has vertically arranged channels, and can be used as a tissue cell reactor.

The invention belongs to the technical field of functional nano composite materials, and particularly relates to a synthetic method of a surface octahedral oxygen vacancy double-shell Co3O4 catalyst with high electro-catalysis chlorine evolution selectivity. Comprising the following steps: firstly, mixing cobalt nitrate hexahydrate, trimesic acid, ethanol and an ethylene glycol solvent according to a certain proportion, and carrying out solvothermal reaction to obtain a spherical Co-BTC precursor; and then the prepared Co-BTC precursor is annealed and oxidized for 1-3 h in air at a certain annealing rate of 1-5 DEG C / min in an environment of 300-500 DEG C, and the hollow double-shell structure material DS-Co3O4 is obtained. Finally, DS-Co3O4 and a sodium borohydride solution are mixed, soaked and stirred for 1-3 h, the double-shell Co3O4 nanospheres with octahedral oxygen vacancies and a multilevel structure are obtained, and high-selectivity electro-catalysis chlorine evolution reaction can be achieved.

The invention provides a preparation method of a gradient porous material loaded noble metal catalyst. The method comprises the following steps: preparing hydroxyapatite powder; the preparation method comprises the following steps: taking hydroxyapatite powder, adding absolute ethyl alcohol, performing ultrasonic dispersion to prepare a suspension, adding polyvinyl butyral, and stirring with a magnetic stirrer to uniformly disperse the polyvinyl butyral to form hydroxyapatite slurry; taking three kinds of Pt catalyst loaded polylactic acid / glycolic acid copolymer microspheres with different particle sizes, and laying the microspheres in a mold according to the particle sizes; pouring the hydroxyapatite slurry into a mold, applying a certain pressure to fill gaps of microspheres with the hydroxyapatite slurry, and completely drying; and sintering in a sintering furnace to obtain the gradient porous material loaded noble metal catalyst. According to the invention, the noble metal catalyst is loaded on the gradient porous material, and the gradient aperture structure can promote the reactants to be guided by the capillary tube and quickly transfer the mass to each active site, so that the rate and efficiency of the selective hydrogenation performance are improved.

This invention discloses an oxygen evolution catalyst with a surface-sulfurized Co3O4 mesoporous layered nanopile structure and its preparation method, belonging to the field of electrochemical energy conversion and storage technology. The preparation method includes: uniformly mixing Co(NO3)2·6H2O with urea in a certain proportion, and performing hydrothermal synthesis to obtain a layered nanopile precursor; further calcining the precursor in air to convert it into a Co3O4 mesoporous layered nanopile; and then immersing it in Na2S solution to obtain a partially sulfur-substituted surface Co3O4 mesoporous layered nanopile, which serves as the oxygen evolution catalyst. The preparation method of this invention is simple, and the obtained catalyst has a large specific surface area, high conductivity, fast mass transfer, stable structure, and excellent electrochemical activity for oxygen evolution.

The present application relates to a microchannel reactor, the microchannel reactor comprises a mixing unit and a flow unit, the mixing unit and the flow unit are interconnected, the mixing unit comprises an air inlet pipe and a mixing tube, one port of the mixing tube is connected to the flow unit, the other port of the mixing tube is used for liquid inlet, the air inlet pipe is connected to the mixing tube and the air inlet pipe is arranged on the outer side wall of the mixing tube; a protrusion is arranged on the inner side wall of the mixing tube, the protrusion faces the port for liquid inlet of the mixing tube, and a concave spiral structure is arranged on the inner side wall of the flow unit; the inner diameter of the mixing tube is 1-3mm, the length of the mixing tube is 1-5cm, the inner diameter of the flow unit is 0.1-1mm, the length of the flow unit is 5-15cm, the ratio of the length of the mixing tube to the length of the flow unit is 1:3-5, and the ratio of the inner diameter of the mixing tube to the inner diameter of the flow unit is 3-10:1. The present application also relates to the application of the above-mentioned microchannel reactor in absorbing gas in ionic liquid.

The invention belongs to the technical field of catalytic materials, and particularly relates to an immobilized enzyme catalyst for preparing chiral alcohol and chiral ester as well as a preparation method and application of the immobilized enzyme catalyst. The preparation method comprises the following steps: 1) adding anionic polyelectrolyte and cationic polyelectrolyte into water, and mixing to form an aggregate; adding an enzyme solution into the aggregate, and uniformly mixing to obtain an enzyme-containing aggregate; (2) adding a porous material into the enzyme-containing aggregate in the step (1), and uniformly stirring to obtain a mixture; and (3) adding a thickening agent into the mixture in the step (2), heating, stirring, carrying out extrusion forming, and drying, so as to obtain the product. The immobilized enzyme catalyst can be directly filled into a fixed bed reactor to carry out an enzyme catalysis reaction so as to obtain chiral alcohol and chiral alcohol ester with high added values, a high-concentration substrate continuously flows to react for 10-30 days, and the enzyme catalysis activity and selectivity are basically kept unchanged.

This invention relates to an asymmetric catalytic composite membrane and its preparation method, belonging to the field of chemical catalytic separation technology. The catalytic composite membrane adopts a three-layer asymmetric composite structure, consisting of a catalytic layer, an intermediate support layer, and a separation layer. The intermediate support layer is placed between the catalytic layer and the separation layer to achieve physical isolation between the two layers, avoiding damage to the separation layer structure during the catalytic layer preparation process. Specifically, the catalytic layer is a sulfonated polyvinyl alcohol (PVA) membrane with a porous structure prepared by freeze-drying technology. After sulfonation modification and freeze-drying to create pores, it exhibits both low mass transfer resistance and high catalytic activity. The intermediate support layer is a polyacrylonitrile (PAN) ultrafiltration membrane, providing stability and isolation. The separation layer is a dense membrane formed by spin-coating MOF-801 nanoparticles with sodium alginate (SA). The hydrophilic MOF-801 nanoparticles significantly improve the water / ethanol separation efficiency. The asymmetric structure of this invention has the characteristic of independent optimization of functional layers, which can enhance the performance of the catalytic layer and the separation layer respectively. The prepared sulfonated polyvinyl alcohol (PVA) catalytic composite membrane exhibits excellent catalytic-separation coupling performance and long-term stability in esterification reaction, and has good prospects for industrial application.

The invention relates to a polyoxometallate cluster, a preparation method and application of the polyoxometallate cluster in a CO2 hydro-conversion process, and belongs to the field of catalytic materials. The invention provides an Anderson type PtMo6O24 cluster which is positioned in a stable metal organic framework, has a clear molecular structure and has a catalytic effect on low-temperature CO2 hydrogenation. After the performance of the cluster is operated for a long time, the activity or methanol selectivity of the cluster does not show an attenuation sign, and the one-way yield of the cluster also exceeds that of the most advanced heterogeneous catalyst. In combination with in-situ spectrum and DFT (Discrete Fourier Transform) calculation, the formation of CH3OH is mainly dominated by reverse water-gas shift and a subsequent CO hydrogenation path, and an HCOO path possibly serves as an auxiliary path. The cluster structure with a clear structure is used for CO2 hydrogenation, and has the characteristics of high activity and low-temperature catalysis.

A method for visible-light catalytic degradation of trace organophosphorus pesticides in aquatic environments involves first preparing functionalized nitrogen carbide materials via high-temperature pyrolysis. Then, zirconium-based MOFs are grown in situ on the surface of the functionalized nitrogen carbide materials, and a highly efficient heterogeneous composite photocatalyst is designed and synthesized. Finally, the trace organophosphorus pesticides in the aquatic environment are rapidly and stably degraded under visible light. The advantages of this invention are: the process is reasonable and easy to implement; the zirconium-based MOFs-modified functionalized nitrogen carbide heterogeneous composite photocatalyst prepared by this method exhibits good visible-light responsiveness and stability for organophosphorus pesticide degradation, achieving efficient adsorption and rapid mass transfer of organophosphorus pesticides; this degradation technology possesses high adsorption capacity, multiple catalytic activities, and strong practicality, greatly facilitating the visible-light degradation of trace organophosphorus pesticides, improving the efficiency of heterogeneous composite photocatalysts, and broadening the application range of functionalized nitrogen carbide materials and zirconium-based MOFs.

The invention discloses a preparation method and application of a high-dispersity cerium-based coordination polymer, and belongs to the technical field of environmental composite functional materials. The preparation method comprises the following steps: by taking a plant phenolic aldehyde solution as a dispersion medium, cerium ions as an inorganic metal center and an organic ligand 2-aminoterephthalic acid as a bridging agent, carrying out high-temperature mixing reaction to obtain Ce-PNTA; the cerium-based coordination polymer prepared by the invention has good dispersibility in water and is not easy to agglomerate and inactivate; the fluorine ions in water can be efficiently adsorbed, the pH window of fluorine ion adsorption in water is widened, fluorine-containing sewage treatment under acidic, neutral and weakly alkaline conditions (pH 7-9) can be realized, the bottleneck that fluorine ions are difficult to separate in neutral and alkaline water is solved, and the fluorine-containing sewage treatment agent has the advantages of environment friendliness and low preparation cost.

The invention discloses a molecular sieve adsorbent which comprises a hierarchical pore hard core and a molecular sieve shell, the hierarchical pore hard core is an inorganic porous ball core with a mesopore-macropore composite structure; the molecular sieve shell is a mixture of molecular sieve raw powder and a crosslinking agent. The invention further discloses a forming method of the molecular sieve adsorbent and application of the molecular sieve adsorbent in a pressure swing adsorption process.

The invention discloses a microreactor for enhancing hydrogen production through symbiosis of phycomycetes and a preparation method of the microreactor, and the preparation method comprises the following steps: uniformly mixing hydrogen-producing microalgae and a sodium alginate solution to obtain a microalgae-sodium alginate solution, then filling the microalgae-sodium alginate solution into an injector of a two-channel microflow pump, and filling a calcium chloride solution into the other injector of the two-channel microflow pump; connecting the two-channel micro-flow pump with a printing head of a 3D printer, respectively pumping out the microalgae-sodium alginate solution and the calcium chloride solution from the printing head according to a preset hydrogen production microalgae kernel model, and printing to obtain a hydrogen production microalgae kernel of the hydrogen production microreactor; the preparation method comprises the following steps: uniformly mixing electroactive bacteria with a chitosan solution to obtain a bacteria-chitosan solution, soaking a hydrogen-producing microalgae core in the bacteria-chitosan solution, and stirring for 25-30 minutes to obtain the hydrogen-producing microreactor. The preparation method disclosed by the invention is simple and high in repeatability, and the prepared hydrogen production microreactor can maintain a long-term anaerobic microenvironment and high hydrogenase activity, so that the hydrogen yield of microalgae can be effectively improved.

The application provides a composite porous fiber aerogel and a preparation method and application thereof, and belongs to the field of functional materials. Polyvinyl alcohol and sodium lignosulfonate are dissolved in water to obtain a PVA solution and an LS solution; the PVA solution and the LS solution are uniformly mixed in proportion to obtain a spinning dope; the spinning dope is atomized into droplets and sprayed into a uniform-speed stirring coagulation bath, so that the droplets form fibers under the stirring and drawing action of the coagulation bath, and solvent-non-solvent exchange and phase separation occur simultaneously to form nascent composite porous fibers; the nascent composite porous fibers are placed in a coagulation bath containing a crosslinking agent for crosslinking treatment and phase separation to obtain crosslinked composite porous fibers, and the crosslinked composite porous fibers are subjected to dispersion, freezing and freeze-drying treatment to obtain the composite porous fiber aerogel. The covalent compounding of polyvinyl alcohol and sodium lignosulfonate and the multi-level pore structure enable the composite porous fiber aerogel to have high adsorption capacity for positive proteins and excellent regeneration performance.

The application relates to the field of fine chemical synthesis, and relates to a preparation method of polyvinylpyrrolidone. Pure water, N-vinylpyrrolidone and ammonia water are continuously introduced into a micro-mixer, uniformly mixed in the micro-mixer, and then introduced into a preheater to be preheated to a reaction temperature; the obtained mixture is sequentially and continuously introduced into a micro-channel reactor and a delay reactor together with an aqueous hydrogen peroxide solution, and the reaction is carried out at normal pressure at 55-80 DEG C; and the product continuously coming out of the delay reactor is a polyvinylpyrrolidone solution. The application is a continuous preparation method which is easy to control in temperature, high in safety, narrow in molecular weight distribution, short in reaction time and easy to industrialize.

The invention provides a hierarchical porous cement-based seawater uranium extraction material and a preparation method thereof. The material is in a multi-layer roll shape, directional pore channels are formed in the material, and macroscopic gaps are formed between layers; calcium carbonate whiskers grow on the inner walls of the directional pore channels in situ; the hierarchical pore cement-based seawater uranium extraction material is prepared from the following final raw materials in parts by weight: 100 to 150 parts of sulphoaluminate cement, 50 to 120 parts of ground steel slag powder, 15 to 40 parts of acrylamide monomer, 0.4 to 1.5 parts of N, N '-methylene bisacrylamide, 0.05 to 0.4 part of ammonium persulfate and 70 to 150 parts of deionized water. The preparation method comprises the following steps: firstly, preparing a KH-550 modified solution and a PAN / DMSO solution, carrying out material amination and vacuum impregnation phase conversion to form a PAN coating layer, and then carrying out amidoximation reaction. According to the material, the marine uranium extraction efficiency and the comprehensive performance of the material are remarkably improved; the method provided by the invention is flexible and controllable in process and has good industrial amplification potential.

The invention relates to the technical field of porous material preparation, and provides a preparation method of salt-template agent synergistically activated attapulgite and application of the salt-template agent synergistically activated attapulgite in a hierarchical porous adsorbing material.The preparation method comprises the following steps that S1, pretreatment is conducted, specifically, attapulgite raw ore is crushed, screened, purified through a wet method and then dried, the purified and dried attapulgite is added into diluted hydrochloric acid with the concentration of 0.5-1.0 mol / L, and the mixture is stirred to be uniform; the solid-to-liquid ratio is 1: 10, stirring at 60 DEG C for 2 hours, carrying out acid treatment, centrifugally washing to be neutral, and drying for later use; the activated attapulgite prepared by the method disclosed by the invention shows an ultrahigh adsorption removal rate on typical macromolecular pollutants. Under the same dosage, the removal rate of the product to macromolecular pollutants is obviously superior to that of a contrast sample, which proves that the method can greatly improve the treatment capacity of the attapulgite, and after high-temperature calcination, the main component of the obtained activated attapulgite is converted into a silicate oxide phase with high thermal stability, so that the treatment effect is greatly improved. Secondary pollution caused by dissolution during use is not easy to occur, and the adsorbent can be used as an efficient and low-cost adsorbent.

The invention relates to the field of heterogeneous catalyst preparation, in particular to a Fischer-Tropsch synthesis catalyst, a preparation method thereof and a Fischer-Tropsch synthesis method. The catalyst comprises an alumina carrier with a fiber structure and Co3O4 nanoparticles dispersed in network gaps formed by the fiber structure, and the Co3O4 nanoparticles exist in the form of a Co3O4 nanoparticle aggregate; the mass ratio of the Co3O4 nanoparticles to the alumina carrier is 1: (3.3-5); in a hydrogen temperature programmed reduction H2-TPR test, the temperature corresponding to the highest value of the first reduction peak of the catalyst is 250-400 DEG C, and the integral area of the reduction peak corresponding to the temperature of 100-400 DEG C accounts for 50-70% of the total integral area of all the reduction peaks. The catalyst is used in a Fischer-Tropsch synthesis reaction, and the selectivity of by-product methane is reduced while a relatively high CO conversion rate is maintained.

The invention discloses a nano-porous palladium-silver alloy self-supporting electrode and a preparation method and application thereof.The preparation method comprises the following steps that (1) palladium, silver and metal particles prone to acid and alkali corrosion are mixed, then the mixture is placed in a smelting furnace to be smelted in an inert atmosphere, and then an alloy ingot is obtained after casting and cooling; (2) cutting the alloy ingot into alloy sheets; and (3) soaking the alloy sheet in an acid solution or an alkali solution for corrosion, taking out the alloy sheet after corrosion, and then cleaning and drying the alloy sheet to obtain the nano-porous palladium-silver alloy self-supporting electrode. According to the invention, the palladium-silver alloy with a three-dimensional bicontinuous nano-porous structure is constructed by utilizing a simple and feasible smelting-etching technology, the palladium-silver alloy is used as a self-supporting electrode for electro-catalytic phenol hydrogenation reaction and has excellent partial hydrogenation activity, selectivity and cycling stability of phenol, the conversion rate of phenol is 91.2%, and the selectivity of cyclohexanone is 98.9%.

The utility model provides an efficient extraction tower internal part which comprises at least one set of first inclined plates, at least one side of each first inclined plate is provided with a set of second inclined plates, the other side of each second inclined plate is provided with a first inclined plate, the included angle between each first inclined plate and the corresponding second inclined plate is larger than 0 degree and smaller than 180 degrees, and each first inclined plate and each second inclined plate are each provided with screen holes; the first inclined plate, the second inclined plate and the sieve holes are arranged in an inclined mode, it is guaranteed that the liquid drop cutting and crushing effect is better, the contact area is increased, the contact area between two liquid phases is remarkably increased, and the inter-phase substance transfer efficiency can be improved; mass transfer is accelerated, the mass transfer process can be faster due to the larger contact area, and the liquid-liquid separation rate is increased; uniform mixing and separation are achieved, more uniform liquid drop breaking is beneficial to formation of a more uniform mixing state, and the separation precision and effect are improved; the separation time is shortened, the time required for achieving a good separation effect can be shortened through efficient liquid drop cutting and crushing, and the overall separation efficiency is improved.

The present invention discloses a molybdenum-based low-platinum electrocatalyst and a preparation method thereof and an application in a proton exchange membrane fuel cell, and belongs to the technical field of fuel cells. The present invention overcomes the disadvantages of existing noble metal electrocatalysts such as high cost and easy deactivation. The present invention synthesizes a variety of molybdenum-based or molybdenum-containing nickel-based bimetallic compounds, such as molybdenum carbide, nickel molybdenum carbide, molybdenum nitride, nickel molybdenum nitride, molybdenum phosphide, and nickel molybdenum phosphide, by combining the confinement effect of nitrogen-containing heteroatoms in nitrogen-containing ligands with a thermal decomposition method, and further loads a low content of platinum (such as metallic platinum, platinum nickel, platinum cobalt, platinum iron) to obtain a molybdenum-based low-platinum electrocatalyst, which has an ultra-thin nanosheet structure, can perform rapid mass transfer and electron transfer, and not only has excellent HOR performance, but also can provide a larger power density and anti-CO poisoning effect as an anode material of a proton exchange membrane fuel cell, and has great potential to replace commercial Pt / C catalysts.

The invention discloses a method for testing the electrochemical behavior of antimony in a deep eutectic solvent and preparing an antimony coating, and particularly discloses a method for preparing a choline chloride-ethylene glycol deep eutectic solvent, a method for testing the electrochemical behavior of Sb < 3 + > / Sb and a method for preparing the antimony coating. According to the invention, the ratio of choline chloride to ethylene glycol is changed from 1: 2 to 1: 3, and the diffusion coefficient of Sb (III) in ChCl-3EG at 333 K is 5.33 * 10 <-7 > cm < 2 >. S <-1 >, which is greater than that of ChCl-2EG (3.06 * 10 <-9 > cm < 2 >. S <-1 >); the apparent activation energy is 32.76 kJ * mol <-1 >, and is less than that of ChCl-2EG (50.723 kJ * mol <-1 >). The mass transfer rate of Sb (III) can be increased by increasing the content of ethylene glycol, the activation energy of electrolytic antimony is reduced, antimony electrolysis is easier, and energy consumption is lower in industrial application. The nucleation mode of Sb (III) in ChCl-3EG under 333 K is three-dimensional continuous nucleation, the nucleation mode of Sb (III) in ChCl-2EG is three-dimensional instantaneous nucleation, and the nucleation of antimony in the ChCl-3EG system is continuously formed along with the growth of antimony. The antimony coating obtained through electro-deposition is granular, and in a ChCl-2EG system, an antimony film gradually changes from particles to short rods and then to a dendritic shape.

The invention belongs to the technical field of food safety, and specifically relates to a synthesis method and application of a zwitterionic covalent organic framework nanosheet. The synthesis method of the zwitterionic covalent organic framework nanosheet comprises: step S1, synthesizing a sulfonic acid covalent organic framework matrix material through a condensation reaction between 2,4,6-trialdehyde phloroglucinol and 2,5-diaminobenzenesulfonic acid monomers; step S2, subjecting the sulfonic acid covalent organic framework matrix material synthesized in step S1 to a substitution reaction with methyl iodide, thereby preparing a zwitterionic covalent organic framework nanosheet material having a negatively charged sulfonic acid group and a positively charged quaternary ammonium group; the zwitterionic covalent organic framework nanosheet material prepared by the synthesis method of the zwitterionic covalent organic framework nanosheet has a regular pore size and a large aspect ratio, which is conducive to the rapid mass transfer of a target object in the material, and at the same time, high-density and regularly distributed zwitterionic active sites of sulfonic acid groups and quaternary ammonium groups enable the material to have a strong ion pair electrostatic attraction.