39results about How to "Good activity and stability" patented technology

The invention belongs to the technical field of bioengineering, and particularly discloses a chimeric enzyme for degrading PET (Polyethylene Terephthalate) as well as a related biological material and application of the chimeric enzyme. The chimeric enzyme for degrading PET provided by the invention is obtained by replacing at least one fragment in an amino acid sequence as shown in SEQ ID No.1-12 on the basis of IsPETase. Compared with IsPETase, the chimeric enzyme for degrading PET provided by the invention has the advantages that the thermal melting temperature is increased by 4.8-31.7 DEG C, the concentration of a degradation product TPA after PET degradation is increased by 1.5-44.5 times, while the application conditions of PET degradation are widened, the PET degradation efficiency can be greatly improved, the recycling rate of the degradation product TPA with high added value is increased, and the chimeric enzyme has important economic value and environmental benefit. The method can be used in the fields of PET degradation, PET degradation agent preparation or PET degradation product preparation and the like.

The invention relates to a high-strength supported noble metal catalyst as well as a preparation method and application thereof. An additive, an adhesive and an extrusion aid are introduced into a carrier to modify the structure of the carrier so as to improve the strength of the carrier, and meanwhile, acidizing treatment is performed to enhance the acid resistance of the carrier in an HCl atmosphere; in addition, the water-resistant strength of the catalyst in water vapor is enhanced by adopting a hydrothermal method to impregnate and load noble metal. Particularly, the catalyst can be used for a reaction for preparing chlorine by catalytic oxidation of HCl and has relatively high catalytic activity.

The invention relates to the technical field of low-carbon olefin hydration, and discloses a low-carbon olefin hydration catalyst and a preparation method thereof, and a method for producing a low-carbon alcohol aqueous solution. The low-carbon olefin hydration catalyst comprises a resin white ball matrix, an adsorption layer and a reaction layer, the adsorption layer is grafted on the outer surface of the resin white ball matrix, and the reaction layer is grafted on the inner surface of the resin white ball matrix; the adsorption layer contains a phenoxy group, an amido group, a pyrrolyl group and a furyl group; the reaction layer contains phenoxy, amido, sulfonic acid group, phosphate group, pyrrolyl and furyl. The low-carbon olefin hydration catalyst can improve the contact effect of water and olefin, promote the movement of hydration equilibrium and reduce the superposition loss of olefin.

The invention discloses a Cu-doped Bi2O2CO3 nanosheet catalyst as well as a preparation method and application thereof, and belongs to the technical field of electrocatalytic carbon dioxide reduction. The preparation method comprises the following steps: 1) uniformly stirring and mixing water, acetic acid and ammonia water in a reaction container to form a mixed solution I, weighing copper nitrate and bismuth nitrate, adding the weighed copper nitrate and bismuth nitrate into the mixed solution I, and stirring to form a mixed solution II; and 2) transferring the mixed solution II into a reaction kettle, putting the reaction kettle into a drying oven for hydrothermal reaction, and after the hydrothermal reaction, naturally cooling, centrifuging, washing, drying and grinding to obtain Cu-doped Bi2O2CO3 nanosheet catalyst powder. The catalyst is obtained through a one-step hydrothermal method and has excellent selectivity and good stability on reduction of carbon dioxide into formic acid through electro-catalysis, the performance is excellent, the preparation method is simple, the cost of raw materials is low, the yield is high, and large-scale production is easy.

The invention discloses a whitening anti-oxidation composition which comprises pterostilbene and phenylethyl resorcinol, and the weight ratio of the pterostilbene to the phenylethyl resorcinol is 1: (0.6-1.5). According to the whitening anti-oxidation composition, the anti-oxidation and whitening effects can be remarkably improved, the anti-oxidation and whitening effects are good, and meanwhile the stability is high. According to the invention, lipidosome is adopted for coating, so that the formed cosmetic raw material has better stability and is not easy to yellow in stability detection, and the content retention effect of pterostilbene and phenylethyl resorcinol is better. The composition is applied to whitening and anti-oxidation products and is small in irritation and high in use stability, the whitening and anti-oxidation effects are further improved, the active oxygen removal rate reaches 68% or above, and the melanin inhibition rate reaches 88% or above.

The present invention provides a Ba and B doped Fischer-Tropsch synthesis iron-based catalyst, comprising Fe element, Cu element, K element and SiO2, wherein the Fischer-Tropsch synthesis iron-based catalyst is doped with Ba element and B element, and by mass ratio, when Fe element:SiO2=100:10-less than 20, Ba element:B element=1-less than 4:1, and when Fe element:SiO2=100:20-40, Ba element:B element=4-6:1. The present invention also provides a preparation method of the Fischer-Tropsch synthesis iron-based catalyst. The Fischer-Tropsch synthesis iron-based catalyst provided by the present invention is doped with a specific content of Ba element and B element, and through the synergistic effect of the two, the catalyst can have very excellent catalytic activity and thermal stability, and its application can significantly improve the production efficiency of the Fischer-Tropsch synthesis process and reduce production costs, so it has very important economic and social value.

The invention discloses a preparation method of a dianion catalyst and application of the dianion catalyst in catalytic degradation of a polyurethane material. The method comprises the following steps: dissolving metal salt in deionized water to prepare a metal salt solution; the method comprises the following steps: taking a nitrogen heterocyclic compound containing hydroxyl or amino as a substrate in a reactor, dropwise adding a metal salt solution into the reactor, and carrying out reflux condensation at 60-150 DEG C for 1-8 hours; dropwise adding an amine compound, reacting after dropwise adding, and carrying out vacuum filtration treatment after the reaction is ended, so as to obtain filtrate; and evaporating the filtrate and drying the product to obtain the dianion catalyst. The basic physical properties such as the hydroxyl value, the amine value and the viscosity of the recycled polyol obtained through degradation of the catalyst are basically equivalent to those of the raw material polyol, and the recycled polyol can partially replace the raw material polyol to be used for preparing the polyurethane flexible foam.

This invention provides a self-supporting one-dimensional nanorod array composite material, its preparation method, and its application, belonging to the field of clean energy harvesting technology. The preparation method provided by this invention includes the following steps: mixing soluble nickel salt, soluble molybdate, and water, and carrying out a hydrothermal reaction to obtain a NiMo precursor; heat-treating the NiMo precursor and a modifier under a protective atmosphere to obtain the self-supporting one-dimensional nanorod array composite material. Experimental results show that the composite material prepared by the method provided by this invention has excellent electrocatalytic water splitting activity and operational stability, and photo-assisted synthesis further enhances the electrocatalytic water splitting activity of the composite material, making it applicable to solar-driven electrocatalytic water splitting.

The invention discloses a preparation method and application of a carbon-based single-atom oxygen reduction reaction electrocatalyst, using dopamine functionalized polypyrrole nanoparticles as a skeleton material, ethylenediaminetetraacetic acid and bipyridine as ligands, and forming a multi-level stable loaded complex with Fe-O and Fe-N coordination structure on the skeleton material through dynamic timing ligand regulation, gradual temperature increase and coordination time control, and then the obtained complex-loaded polypyrrole nanoparticles are subjected to 200-300°C low-temperature pre-calcination, corrosive gas etching and 500-900°C high-temperature step-by-step calcination treatment to stably generate FeN4 / Fe2O3 active site structure linked by N-Fe-O bridge bonds, and at the same time obtain a rich pore structure to optimize the contact between electrolyte and active site, and finally prepare a carbon-based single-atom oxygen reduction reaction electrocatalyst. The oxygen reduction reaction electrocatalyst prepared by the present invention exhibits excellent catalytic activity and catalytic stability.

The invention discloses an antibacterial peptide as well as a preparation method and application thereof. The amino acid sequence of the antibacterial peptide is LKVVFKVLFKRRR. The antibacterial peptide disclosed by the invention has relatively excellent antibacterial activity and metabolic stability and relatively low hemolytic activity and cytotoxicity, and is expected to become a novel antibacterial candidate drug. In addition, the antibacterial peptide is short in polypeptide sequence and only contains 13 amino acids, and all the amino acids are L-type amino acids, so that the antibacterial peptide is convenient to produce, low in production cost and beneficial to application and popularization. Generally speaking, the antibacterial peptide provided by the invention lays a foundation for further development of novel antibacterial drugs.

The invention relates to the technical field of high-activity metal powder, in particular to high-environmental-stability aluminum-lithium alloy powder and a manufacturing method and application thereof.The high-environmental-stability aluminum-lithium alloy powder comprises, by weight, 1.0-10.0 wt.% of Li, 1.0-10.0 wt.% of Al, 1.0-10.0 wt.% of Ti, 1.0-10.0 wt.% of Ti, 1.0-10.0 wt.% of Ti, 1.0- 0.1 to 5.0 wt.% of Zr; 0.01 to 2.0 wt.% of Ti; 0.05 to 3.0 wt.% of RE; wherein RE is a rare earth element and at least comprises Y, Ce, La or a combination thereof, the sum of Zr, Ti and RE does not exceed 8.0 wt.%, and the balance is Al and inevitable impurities. The method has the effect of improving the use stability and the machining consistency of the aluminum-lithium alloy powder.

The invention relates to the technical field of photocatalytic materials, and provides a preparation method and application of a Zn QDs / ZnWO4 photocatalytic material. The method comprises the following steps: (1) in the presence of a first solvent, mixing zinc acetate and sodium tungstate, and carrying out hydrothermal reaction to obtain a zinc tungstate photocatalytic material; and (2) in the presence of a second solvent, mixing zinc acetate and the zinc tungstate photocatalytic material, reacting under the condition of mercury illumination, and then drying in vacuum to obtain the Zn QDs / ZnWO4 photocatalytic material. The photocatalytic material shows excellent photocatalytic reduction activity on Cr (VI), the purification efficiency of the photocatalytic material on Cr (VI)-containing wastewater after illumination for 40 min reaches up to 99%, and the photocatalytic reduction efficiency of the Zn QDs / ZnWO4 photocatalytic material on the Cr (VI)-containing wastewater can still be kept at 96% or above after ten times of cycle experiments.

The invention discloses a preparation method of a ruthenium-manganese alloy catalytic material, which comprises the following steps: adding ruthenium chloride, manganese acetate and cetyltrimethylammonium bromide into a polyacrylonitrile solution with the mass fraction of 10-12% (the solvent is N, N-dimethylformamide), the mass ratio of ruthenium chloride to polyacrylonitrile is 1: 15, and the mass ratio of manganese acetate to ruthenium chloride is (1-5): 1; the self-supporting RuMn alloy catalyst (C (at) RuMn / CNFs) is prepared by utilizing electrostatic spinning and high-temperature carbonization, and the RuMn alloy particles are wrapped by a plurality of carbon layers, so that the method has the advantages of no need of adopting a binder, no covering of catalytic active sites and no shedding of the RuMn catalyst.

The invention discloses a catalyst as well as a preparation method and application thereof, tungsten trioxide nanorods and powdered sulfur are subjected to vulcanization reaction to generate tungsten disulfide, and tungsten disulfide is subjected to plasma etching to obtain a catalyst intermediate; dispersing the catalyst intermediate in a rhodium salt solution, separating and drying to obtain the catalyst; or the tungsten trioxide nanorod can be firstly loaded on the conductive carrier and then subjected to the steps of vulcanization, plasma etching and rhodium loading, and the catalytic material is obtained; the catalyst and the catalytic material provided by the invention have low cost and high hydrogen evolution catalytic efficiency, especially show good catalytic activity and stability under acidic and alkaline conditions, and are expected to realize practical application in the field of hydrogen production by electrolysis of water.

The invention relates to a catalyst for hydrogen production through seawater electrolysis based on a metal ruthenium-doped copper nanowire composite structure and a synthesis method thereof, and belongs to the technical field of catalysis, the catalyst is composed of a copper nanowire skeleton derived from foamy copper and metal ruthenium clusters uniformly distributed on the surface of the copper nanowire skeleton; the method comprises the following steps: placing foamy copper in a solution containing sodium hydroxide and an oxidizing agent to generate a copper hydroxide nanowire; metal ruthenium is introduced by dipping in a solution containing ruthenium salt; and carrying out inert atmosphere heat treatment and electrochemical reduction to obtain the ruthenium-cluster-loaded copper nanowire composite catalyst. The fine regulation and control of the structure and components of the catalyst are realized by adjusting the concentration of the reaction solution, the dipping time and the treatment conditions. The electrocatalyst shows excellent hydrogen evolution activity and long-term stability under the acidic seawater electrolysis condition, the problems that a nickel-based current collector is prone to corrosion in an acidic medium and a traditional platinum-based catalyst is prone to inactivation in natural seawater are effectively solved, and a new technical scheme is provided for efficient and stable seawater electrolysis hydrogen production.

The application relates to a high-entropy alloy carbon nanofiber material and a preparation method and application thereof. The preparation method of the high-entropy alloy carbon nanofiber material comprises the following steps: S1. polyacrylonitrile is prepared into first spinning liquid, electrostatic spinning is carried out, and first nanofiber film is prepared; S2. polyvinylpyrrolidone, a cobalt source, a nickel source, a copper source, a zirconium source and a metal M source are prepared into second spinning liquid, the second spinning liquid is electrostatically spun, the formed second nanofiber film is covered on one face of the first nanofiber film, and a composite nanofiber film is obtained; and S3. the composite nanofiber film is subjected to pre-oxidation and carbonization treatment, and the high-entropy alloy carbon nanofiber material is obtained. The high-entropy alloy carbon nanofiber material has good flexibility and good hydrogen evolution catalytic performance brought by high content of active substances, and the preparation method does not need to use noble metals as raw materials.

The invention provides a bimetallic compound as well as a preparation method and application thereof. The bimetallic compound provided by the invention is designed by comprising Cr, group IVB bimetallic and a specific ligand; according to the present invention, the catalyst has the excellent catalytic activity, the excellent high-temperature stability and the high alpha-olefin insertion rate in the ethylene polymerization reaction to prepare the polyolefin elastomer, and the polyolefin elastomer obtained through catalysis has advantages of high molecular weight and high 1-octene insertion rate, and can achieve the good rigid-tough balance and the good low-temperature cold brittleness resistance; good application prospects are realized.

A C-terminal truncated alginate lyase and its application. This invention belongs to the fields of bioengineering, genetic engineering, and enzyme engineering, and relates to a C-terminal truncated alginate lyase TY2 designed with molecular docking assistance, its encoding gene, recombinant vector, strain, and its application in the preparation of low-polymerization degree alginate oligosaccharides. Using wild-type MhAly6 as the parent, the truncation boundary was determined through structural prediction and molecular docking. A portion of the linker peptide was retained, and the C-terminal GH28 family domain was deleted to obtain the truncated form TY2. TY2 has approximately twice the specific activity of the wild-type enzyme, and even higher residual activity after incubation at 45°C for 1 hour, achieving a synergistic improvement in catalytic activity and thermal stability. + The relative enzyme activity reached 4.3 times that of the control group, which can degrade pretreated Sargassum powder. The product is mainly ΔDP2–ΔDP4 low-polymerization brown algae oligosaccharides, which are suitable for related enzymatic degradation and oligosaccharide preparation.

The invention belongs to the technical field of gene engineering, and particularly relates to a 3-ketosteroid-delta1-dehydrogenase mutant with improved heat resistance and an application of the 3-ketosteroid-delta1-dehydrogenase mutant. The 3-ketosterone-delta1-dehydrogenase AuKsdD gene derived from arthrobacter urate oxydans is subjected to structural analysis and site-directed mutagenesis design, and a mutant with higher catalytic activity and remarkably enhanced heat resistance compared with a wild type AuKsdD is obtained through directed mutation of key sites E244, K267, T301 and A335. The mutant can keep high catalytic efficiency for a long time under a high-temperature condition, and is suitable for industrial synthesis of steroid drug raw materials.

The invention discloses a production process method of ethyl chloroformate, which specifically comprises the following steps: S1, placing absolute ethyl alcohol in a reactor, cooling, and adding a low-temperature catalyst; s2, introducing phosgene into the reactor while maintaining the introduction temperature; s3, after phosgene is completely introduced, heating to a reaction temperature, keeping the temperature for reaction, and purifying after the reaction is finished to obtain ethyl chloroformate. The prepared low-temperature catalyst is used for reaction, so that the reaction yield and purity are improved, and the method has a wide application prospect.

The invention discloses a skin repair composition, a preparation method and application thereof and a skin care product. The skin repair composition comprises polyquaternium-65, phytosphingosine and D-panthenol. According to the skin repairing composition, the polyquaternium-65, the phytosphingosine and the D-panthenol are compounded for use, the solubility of the phytosphingosine in water and alcohol can be improved, then the skin repairing composition has good activity stability and transdermal absorption efficiency, meanwhile, the polyquaternium-65 can further reduce the irritation of the phytosphingosine, and the skin repairing composition has the advantages that the skin repairing composition is good in skin repairing effect and good in skin repairing effect. The safety of the skin repairing composition is effectively improved, the respective effects of the polyquaternium-65, the phytosphingosine and the D-panthenol are also reserved, and the components complement each other and have a synergistic effect, so that the skin repairing composition can have better skin repairing and protecting effects.

The invention provides a preparation method of gamma aluminum oxide, which comprises the following steps: taking a meta-aluminate solution as an aluminum source, dropwise adding a precipitant solution into the meta-aluminate solution to generate an aluminum oxide precursor, separating the aluminum oxide precursor, drying and roasting to obtain the gamma aluminum oxide, and the precipitant is sulfate, sulfite, bisulfate or bisulfite. The invention also provides the gamma aluminum oxide prepared by the preparation method and application of the gamma aluminum oxide. The invention also provides a gamma alumina loaded palladium catalyst and application thereof. The preparation method provided by the invention is simple and convenient in process, mild in condition, wide in raw material source, low in cost and high in safety, the gamma aluminum oxide provided by the invention is very suitable for being used as a carrier of a supported noble metal catalyst, and the catalytic activity and thermal stability of the catalyst can be remarkably improved; the gamma alumina loaded palladium catalyst provided by the invention can be used for catalyzing oxidative degradation of volatile organic compounds such as ethylene and methane.

The invention relates to the technical field of metal prostheses, in particular to a composite porous biological ceramic metal prosthesis and a preparation method thereof.The composite porous biological ceramic metal prosthesis comprises a metal matrix, the metal matrix is made of Ti6Al4V alloy and has a 30-70% gradient porosity structure, and the aperture range is 200-600 micrometers; the surface of the metal matrix is covered with the biological ceramic coating, and the biological ceramic coating is composed of the following components in parts by weight: 60-80 parts of hydroxyapatite HA; according to the present invention, the excellent mechanical property and the biocompatibility of the Ti6Al4V alloy are utilized, and the structural characteristics of the natural bone tissue are simulated through the design of the gradient porous structure; on the nanoscale, the synergistic effect of the HA and the beta-TCP crystals creates a dynamically changing biological activity interface. The stable structure of the HA provides a good adhesion matrix for cells, and the moderate degradation of the beta-TCP continuously releases calcium and phosphorus ions.

The application provides a preparation method and application of a PdCd catalyst, and belongs to the technical field of fuel cell catalysts. The PdCd nanowire with an ordered intermetallic compound structure is directly synthesized under mild conditions through specific raw material combination and one-step hydrothermal method, and high-temperature post-treatment or template assistance is not needed, so that the process is simple and the operation is convenient. The obtained catalyst has the nanowire morphology and the ordered intermetallic compound structure, and when being used for the anode ethanol oxidation reaction of a direct ethanol fuel cell, the catalyst shows excellent catalytic activity and long-term stability. The preparation method provided by the application has wide raw material sources, mild reaction conditions and good reproducibility, and provides a new technical path for the development of a high-performance anode catalyst of a direct ethanol fuel cell.

The application relates to the technical field of inorganic materials, in particular to a sulfur-defect-rich CuS and a preparation method and application thereof. The preparation method comprises the following steps: S1, mixing CuS, a dispersing agent and an organic sulfur source in the presence of a solvent to form a slurry; S2, performing wet ball milling on the slurry, performing solid-liquid separation, taking the solid, washing and drying to obtain a precursor; S3, annealing the precursor under vacuum to obtain the sulfur-defect-rich CuS; wherein the wet ball milling process adopts intermittent ball milling at a rotating speed of 400-600 r / min for 2-4 h. Through the above wet ball milling, sulfur source induction and vacuum heat treatment steps, the sulfur-defect-rich CuS can efficiently remove selenium in wastewater.

The invention provides a sulfur-tolerant hydrodechlorination catalyst with a core-shell structure as well as a preparation method and application of the sulfur-tolerant hydrodechlorination catalyst. The sulfur-tolerant hydrodechlorination catalyst disclosed by the invention is prepared by adopting an impregnation method, and a carrier takes C12A7 with a cage cavity structure as a core and TiO2 as a shell layer; the C12A7 of the cage cavity structure has abundant micro channels, so that Cl <-> and O2 <-> can enter conveniently, and meanwhile, a larger reactive surface is provided; tiO2 is a shell layer and forms a hydrodechlorination active center together with the active component; the three components have a synergistic effect, so that the hydrodechlorination activity can be improved, and the activity stability in a chlorine-containing atmosphere can be maintained; the sulfur-tolerant hydrodechlorination catalyst is sulfur-tolerant, is suitable for sulfur-containing atmosphere, and has no sulfur tolerance upper limit; the sulfur-tolerant hydrodechlorination catalyst disclosed by the invention is good in activity and stability, and is resistant to gases such as HCl which are toxic to the catalyst; the sulfur-tolerant hydrodechlorination catalyst with the core-shell structure is high in strength, and the crushing strength of particles is larger than or equal to 100 N / cm.

The invention relates to an ultra-high molecular weight polyethylene fiber / carbon fiber reinforced porous high-density polyethylene composite material as well as a preparation method and application thereof. The composite material comprises the following raw material components in percentage by weight: 10%-30% of fibers, 70%-90% of high-density polyethylene particles or powder and spherical calcium carbonate powder, the fibers are ultra-high molecular weight polyethylene fibers and carbon fibers, and the weight ratio of the ultra-high molecular weight polyethylene fibers to the carbon fibers is 9: 1-7: 3. The composite material is high in strength, and the bending strength reaches 60 MPa or above. And when being used as an auricle stent, the material has better biological activity and structural stability.

The invention belongs to the technical field of catalyst preparation, and discloses a Beta molecular sieve confinement type noble metal catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: synthesizing a Beta molecular sieve (N-Beta) catalyst carrier containing auxiliary active metal N (N = Zn, Sn, Y, Co and Cu) by a hydrothermal method, and introducing main active metal M (M = Pt, Pd, Rh and Ir) into a pore channel of the N-Beta molecular sieve carrier by an ion exchange method. The M-N-Beta catalyst provided by the invention can provide stable propylene space-time yield which is more than two times higher than a literature value at the same temperature.

The invention discloses a ruthenium-doped phosphatized Prussian blue analogue electrocatalyst and a preparation method and application thereof, and the preparation method comprises the following steps: firstly preparing NiFe PBA by taking nickel nitrate hexahydrate, sodium citrate and potassium ferricyanide as raw materials, then preparing Ru / NiFe PBA by Ru doping, and finally preparing Ru / NiFeP by phosphating. The contents of Ru, Ni, Fe and P in the prepared Ru / NiFeP are 10%, 19%, 18% and 53% respectively, and the Ru / NiFeP is used for alkaline oxygen evolution reaction, has excellent catalytic activity and stability and low overpotential, and can be as low as 264 mV at 10 mA cm <-2 >.

The invention discloses a synthetic method of a crystalline / amorphous cobalt manganese oxide catalyst, which specifically comprises the following steps of: uniformly mixing cobalt acetylacetonate and manganese acetylacetonate serving as metal precursors and alkali metal salt serving as a reaction aid, calcining at high temperature, and washing and drying an obtained product after calcining to obtain crystalline / amorphous CoMnOx; wherein the calcination temperature is between the melting points of the metal precursor and the alkali metal salt. The invention also discloses an application of the crystalline / amorphous cobalt-manganese-oxygen catalyst prepared by the synthetic method in preparation of CO by photocatalytic reduction of CO2. The crystalline / amorphous cobalt manganese oxide catalyst prepared by the synthesis method has good photocatalytic activity and catalytic stability when applied to CO preparation by photocatalytic reduction of CO2, and can effectively improve the CO production rate in unit time, thereby greatly improving the photocatalytic conversion efficiency of CO2-CO. The invention also discloses an application of the crystalline / amorphous cobalt-manganese-oxygen catalyst prepared by the synthetic method in preparation of CO by photocatalytic reduction of CO2.