12results about How to "Small average pore size" patented technology

The invention relates to a catalyst for preparing allyl acetate through acetylation of propylene and a preparation method of the catalyst. The catalyst comprises a carrier, active components and an auxiliary agent, the average pore size of the carrier is 20-100 nm, the active components are bimetallic palladium Pd and antimony Sb, and the auxiliary agent is potassium acetate. The invention mainly solves the problems of low conversion rate, low selectivity, short service life and the like of the catalyst used in the current acryl acetylation reaction. Compared with the prior art, the catalyst provided by the invention has the advantages of high conversion rate and high selectivity on the acetylation reaction of the propylene, and solves the problem of poor stability of the existing catalyst.

The invention discloses a novel carbonized polybenzoxazine aerogel and a preparation method thereof, the novel carbonized polybenzoxazine aerogel is prepared by carbonizing a novel polybenzoxazine aerogel, and the invention belongs to the technical field of aerogel materials. The preparation method comprises the following steps: preparing a polybenzoxazine solution; putting the polybenzoxazine solution into a mold to form wet gel; aging the wet gel, and drying at normal pressure for 24 hours after aging; the aged wet gel is washed with N, N-dimethylformamide, and wet conductive gel is obtained; and drying the wet gel at normal temperature and normal pressure to obtain the novel polybenzoxazine aerogel. The polybenzoxazine aerogel is subjected to heat preservation for 6 hours at the temperature of 800 DEG C in an argon environment to be carbonized, then furnace cooling is carried out, and the novel carbonized polybenzoxazine aerogel is obtained after the polybenzoxazine aerogel is cooled. The preparation method has the advantages that the bisphenol F type benzoxazine monomer is used as a raw material, and the preparation method is simple through acid catalytic polymerization and normal-pressure drying; compared with other aerogel materials, the aerogel disclosed by the invention has excellent electromagnetic shielding performance and relatively high resistivity.

The invention discloses a preparation method of secondary cross-linked resin and the secondary cross-linked resin, and relates to the technical field of high-molecular polymers. The preparation method comprises the following steps: adding a cross-linking agent with a disulfide bond in the synthesis process of polystyrene resin for reaction to prepare first cross-linked resin containing the disulfide bond; reducing the disulfide bond in the first cross-linked resin into sulfydryl by using a reducing agent to prepare sulfydryl-containing second cross-linked resin; and carrying out sulfydryl-alkene click reaction on residual double bonds in the second cross-linked resin and sulfydryl to prepare the secondary cross-linked resin. The invention aims to solve the problem that an existing adsorbent is poor in adsorption effect and separation effect on target substances.

The invention relates to a rare earth element Ho modified Ni-based catalyst and a preparation method and application thereof, the rare earth element Ho modified Ni-based catalyst comprises an active component and an auxiliary agent, the active component is NiO, and the auxiliary agent is Ho2O3; the molar ratio of Ho to Ni in the Ni-based catalyst modified by the rare earth element Ho is (0.002-0.008): 1. The auxiliary Ho2O3 is introduced, and the molar ratio of Ho to Ni in the rare earth element Ho modified Ni-based catalyst is regulated to be (0.002-0.008): 1, so that on one hand, the specific surface area and pore volume of NiO can be increased, the average pore size can be reduced, and exposure of active sites is promoted; on the other hand, edge dislocation and defect structures are formed through induction, generation of oxygen vacancies is facilitated, and therefore the catalytic performance is further improved.

The application relates to the technical field of water vapor shift, and discloses a water vapor shift catalyst, a preparation method and application thereof, and a water vapor shift reaction method, wherein the catalyst comprises aluminum oxide, active elements and auxiliary elements; the auxiliary elements are selected from at least one of Co, Ni, Cr, Cu and Ce; the active elements comprise divalent iron and trivalent iron, and the atomic ratio of the divalent iron and the trivalent iron on the surface of the catalyst is not less than 0.3 measured by XPS. The catalyst is applied to a water vapor shift reaction, can be suitable for a low water-gas ratio condition, has a high CO conversion rate and a high hydrogen production rate under a high air speed condition, has good heat-resistant activity, and has a high activity retention rate after high-temperature treatment.

This invention relates to the field of sodium-ion battery technology, specifically to a modified hard carbon material and its preparation method, a negative electrode sheet, and a sodium-ion battery. The modified hard carbon material is obtained by mixing and grinding a hard carbon precursor with naphthalene at a mass ratio of 5-9:1-5, followed by a two-stage heat treatment. This invention utilizes the gas-phase infiltration and high-temperature carbonization of naphthalene at specific temperatures. In the first stage, naphthalene is converted into gaseous molecules. Its small kinetic diameter allows it to penetrate deep into the micropores of the hard carbon precursor and be adsorbed under capillary action and pressure difference. In the second stage, naphthalene undergoes pyrolysis, transforming in situ into an amorphous soft carbon layer. This achieves uniform and deep filling of carbon within the micropores of the hard carbon, effectively reducing the average pore size. This not only promotes the pre-desolvation of solvated sodium ions but also helps to obtain an ultrathin and stable NaF-rich solid electrolyte interface film, improving the rate performance of the material. Furthermore, this process is simple, efficient, and low-cost, which is beneficial for large-scale production.

The invention discloses a one-step synthesis of a heavy metal and sulfur poisoning-resistant denitrification synergistic CO / CH removal multifunctional catalyst by solid phase high-speed high-pressure ball milling method and its application. The catalyst is a doped molecular sieve Me1O synthesized by solid phase high-speed high-pressure ball milling method in one step. x ‑Me (Ⅰ) O x ‑R1O2‑Me2O x ‑Me (Ⅱ) O x ‑ZSM‑5, where Me1 is one of V, Ce, and Mn; Me2 is one of Fe, Co, and Cu; (Ⅰ) One of W, Mo, P, S, Me (Ⅱ) is one of La, Pr, Gd and Y, R1 is one of Zr and Ti, and x=1-3. The catalyst of the present invention has the characteristics of large specific surface area, uniform particle size, large number of surface acid sites, small average pore size, multiple redox active centers, high hydrothermal stability, strong resistance to sulfur poisoning and heavy metal poisoning, etc.; its one-step synthesis has the advantages of simplicity, economy and high efficiency.

This invention discloses a method for preparing a composite nanofiltration membrane by electrospinning with a mixed solvent. The method includes dissolving polyacrylonitrile (PAN) in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), stirring the solution until it is completely transparent under water bath heating, and allowing it to stand to remove bubbles to obtain a PAN electrospinning solution; electrospinning the PAN solution to form a membrane, and then hot-pressing and drying it to obtain a PAN nanofiber membrane; impregnating the PAN nanofiber membrane with a piperazine (PIP) aqueous solution, tumbling it with a rubber roller, and adding a trimesoyl chloride (TMC) n-hexane solution to synthesize polyamide (PA) as the top layer to obtain a PA / PAN composite nanofiltration membrane. This composite membrane has high flux and rejection rate for both salts and dyes.

This application discloses a puncture-resistant zinc-bromine flow battery separator, its preparation method, and its application. The puncture-resistant zinc-bromine flow battery separator comprises the following raw materials: ultra-high molecular weight polyethylene, plasticizer, pore-forming agent, color masterbatch, bromine-resistant agent, and lubricant. The pore-forming agent consists of a first inorganic nanoparticle and a second inorganic nanoparticle, the second inorganic nanoparticle being an inorganic nanoparticle with an intrinsically regular pore structure. The zinc-bromine flow battery separator of this application selects the second inorganic nanoparticle with an intrinsically regular pore structure at the angstrom level. This second inorganic nanoparticle synergistically interacts with the first inorganic nanoparticle in the separator, jointly forming a multi-scale sponge-like three-dimensional network structure. This reduces the average pore size of the separator, which is beneficial for improving the bromine barrier capacity of the separator and increasing the coulombic efficiency of the battery.

The invention discloses a composite diaphragm as well as a preparation method and application thereof, and relates to the field of flow batteries. The composite diaphragm comprises a basement membrane and a modified coating located on one side or two opposite sides of the basement membrane, the basement membrane comprises a middle layer and a transition layer which are integrally formed, the basement membrane is made of polymer resin, and the transition layer is formed by permeating components of the modified coating into the basement membrane; the modified coating comprises a filler and a binder, and the filler is at least one of a carbon material, a metal oxide and a mesoporous material. According to the composite diaphragm, the surface structure is reconstructed through the modified coating, the average pore size of the surface layer is reduced, when the composite diaphragm is applied to charge and discharge of the flow battery, the shuttle of active substances in an electrolyte can be blocked, the ion selective permeability is improved, the coulombic efficiency and the specific discharge capacity of the flow battery are remarkably improved, and the flow battery has excellent cycle stability.

This invention discloses a method for preparing silicon-carbon composite anode materials using porous graphite. First, a porous carbon material with a large number of uniformly distributed nano- to micron-sized pores is prepared using a physical foaming method, and then graphitized at high temperature to obtain porous graphite. Next, the porous graphite is pulverized to obtain graphite powder with a cratered surface structure, and then mixed with a certain proportion of nano-silicon and ball-milled to embed the nano-silicon into the cratered structure on the graphite powder surface. Finally, the mixed material is carbon-coated to obtain a silicon-carbon composite anode material for lithium-ion batteries. Applications of this composite material are also provided. In this invention, nano-silicon and graphite have good electrical contact, greatly improving the electrochemical performance of the silicon-carbon composite anode material. Simultaneously, graphite can buffer the volume expansion of the silicon material. The cratered structure on the graphite surface improves the lithium intercalation reaction of the silicon-carbon composite anode material, improving the rate capability and low-temperature performance of lithium-ion batteries.

The invention provides a porous polymer foam material prepared based on a high internal phase emulsion template method and application thereof, the preparation method comprises the following steps: (1) mixing a vinyl monomer, a cross-linking agent, alkyl (meth) acrylate, an emulsifier, magnetic nanoparticles and a tracer agent to obtain an oil phase component; mixing water, electrolyte and an initiator to obtain a water-phase component; adding the water-phase component into the oil-phase component, and emulsifying to obtain a water-in-oil high-internal-phase emulsion; (2) depositing the water-in-oil type high internal phase emulsion obtained in the step (1) on a carrier substrate, and applying a pulsed magnetic field; (3) carrying out plasma treatment on the water-in-oil type high internal phase emulsion obtained in the step (2); curing in an eddy current induction area; in the step (3), a Fourier transform infrared spectrometer is adopted to monitor the concentration of each component on line, and signals are transmitted to a model prediction controller. The preparation method solves the problems of surface adhesion, oxygen inhibition and incomplete curing in the curing process.