11results about How to "Fast mass transfer" patented technology

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.

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 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 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 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.