9results about How to "Reduce catalytic activity" patented technology

The invention relates to an interface engineering method of Zn0. 5Cd0. 5S loaded on a high-entropy sulfide cocatalyst and an application of the Zn0. 5Cd0. 5S. According to the method, firstly, a high-entropy sulfide FeCoNiCrAlSx (HES) is synthesized by adopting a solvothermal method, then the high-entropy sulfide HES is introduced into a Zn0. 5Cd0. 5S system through a one-step coprecipitation method, a compact interface is formed between FeCoNiCrAlSx and Zn0. 5Cd0. 5S, and meanwhile, FeCoNiCrAlSx provides abundant active sites. The obtained composite material can promote effective separation and transfer of photo-induced electron holes, the photocatalytic hydrogen production activity of Zn0. 5Cd0. 5S is remarkably improved, and new possibility is provided for designing an efficient and stable non-noble metal photocatalytic system.

This invention relates to the field of agricultural biotechnology, specifically to the phytoene dehydrogenase mutant Y201F and its application in carotenoid synthesis. The amino acid sequence of the phytoene dehydrogenase mutant is shown in SEQ ID NO: 2. The phytoene dehydrogenase mutant provided by this invention can specifically reduce the catalytic activity of the fifth dehydrogenation reaction of phytoene dehydrogenase, guiding the metabolic flux to accumulate the intermediate product lycopene, which is then catalyzed by lycopene cyclase to generate β-carotene and γ-carotene. This achieves targeted regulation of different carotenoid synthesis pathways, providing novel key enzyme elements and metabolic regulation strategies for the targeted biosynthesis of different carotenoids, and has significant application value and technical significance in the fields of food, medicine, and cosmetics.

This application discloses a method for synthesizing polyethylene (2,5-furandicarboxylate), comprising the following steps: mixing 2,5-furandicarboxylic acid and ethylene glycol in a molar ratio of 1:2, adding zinc acetate as an esterification catalyst, and carrying out an esterification reaction at 195°C and a pressure not exceeding 0.3 MPa until the water content reaches 98% of the theoretical amount; adding antimony trioxide as a polymerization catalyst and triphenyl phosphate as a stabilizer to the esterification product, and reacting for 1 hour at a low vacuum of 800-1000 Pa and a temperature of 215°C to carry out pre-condensation; and carrying out a condensation reaction of the pre-condensation product at a high vacuum of less than 200 Pa and a temperature of 235°C until the torque reaches 4.2 A / 65 rpm to obtain polyethylene (2,5-furandicarboxylate). By reducing the amount of antimony trioxide to 0.045% and triphenyl phosphate to 0.1%, the amount of stabilizer was reduced, releasing catalyst activity. This shortened the polymerization time from 300 min to 230 min, reduced the color value b from 12-13 to 10, and improved the intrinsic viscosity to 0.507~0.517 dL / g. This achieved a reduction in production costs and heavy metal residues while improving the product's color.

The application provides an aluminum-doped hematite, a preparation method thereof and application of the aluminum-doped hematite in catalyzing degradation of organic pollutants by peroxide or removal of pathogenic bacteria. The preparation method of the aluminum-doped hematite comprises the following steps: adding a ferric salt and an aluminum salt into deionized water, precipitating the product after reaction, and then washing, drying and grinding the product to obtain a precursor; and then calcining the precursor, and then washing and drying the aluminum-doped hematite. The preparation method is simple, raw materials are cheap and easy to obtain, the cost is low, and the method is green, safe and environmentally friendly. The catalytic activity of the hematite is improved by introducing aluminum elements into the hematite, and the catalytic conditions are easy to realize. The aluminum-doped hematite has excellent ability of activating peroxide, and thus has excellent performance in removing environmental organic pollutants and sterilization.

This invention relates to the field of cyclic carbonate synthesis technology, specifically to a method for the continuous preparation of cyclic carbonates. The method includes the following steps: (1) mixing an epoxide compound and a solvent to obtain a homogeneous mixture; (2) in the presence of a quaternary ammonium salt coordination bimetallic catalyst, reacting the homogeneous mixture with CO. 2 A synthetic reaction is carried out to obtain cyclic carbonate products. This invention utilizes a specific quaternary ammonium salt-coordinated bimetallic catalyst, which can continuously, efficiently, controllably, and precisely catalyze the preparation of cyclic carbonates from raw materials. The catalyst's catalytic activity shows almost no decrease after 24 hours of continuous use. The catalyst in the reactor is insoluble in the reaction solution, thus simplifying the subsequent separation process and reducing the use of expensive catalysts. Using the method of this invention, the reaction time is reduced from hours to minutes, greatly improving the reaction efficiency.

The application discloses a concentrated solution of levetiracetam for injection, which contains levetiracetam, sodium danshensu, sodium chloride, sodium acetate trihydrate and glacial acetic acid, and a preparation method thereof. The concentrated solution of levetiracetam for injection can reduce the generation of impurities of levetiracetam after compounding, and has a synergistic effect in anti-seizure and neuroprotection.

The present application relates to a kind of for electrolytic hydrogen production with the preparation method and its application of nitrogen-doped carbon material as carrier load ruthenium catalyst, wherein with the preparation method of nitrogen-doped carbon material as carrier load ruthenium catalyst, it includes the following steps: (1) the preparation of nitrogen-doped carbon carrier;Melamine, lignin or the uniform mixing of primary biomass containing lignin obtains the precursor of nitrogen-doped carbon material;The precursor is calcined under high-temperature argon atmosphere to obtain nitrogen-doped carbon material.(2) load ruthenium on nitrogen-doped carbon carrier;After the uniform mixing of precursor ruthenium salt and nitrogen-doped carbon material is dried, it is calcined under high-temperature hydrogen atmosphere to obtain with the preparation method of nitrogen-doped carbon material as carrier load ruthenium catalyst.The operation is simple, and part of carbon comes from natural biomass, and the cost is low, and the catalyst obtained in catalytic hydrogen evolution process has higher catalytic activity.

The application discloses a kind of immobilized chiral phosphoric acid catalyst and its preparation method and application, belong to the field of catalyst immobilization.The method includes the following steps: S1.chiral phosphoric acid is reacted with 1-chloromethyl-4-vinylbenzene, and 4-vinylbenzyl structural unit is entered on chiral phosphoric acid skeleton, to obtain heterogeneous chiral phosphoric acid monomer;S2.the heterogeneous chiral phosphoric acid monomer, styrene and divinylbenzene are polymerized under the action of initiator, to obtain immobilized chiral phosphoric acid catalyst.The present application realizes the introduction of polymerizable monomer unit by one-step Friedel-Crafts alkylation reaction, greatly simplifies the process.The obtained immobilized catalyst is not only easy to recover, after continuous circulation multiple uses, its catalytic activity and enantioselectivity do not see significant decline, provides efficient, economical solution for the scale industrial application of chiral phosphoric acid catalyst.

This invention relates to the fields of air pollution control and solid waste disposal in advanced environmental protection industries, and particularly to a carbon monoxide catalytic combustion catalyst and its preparation method. The preparation method of the carbon monoxide catalytic combustion catalyst includes: Step A, crushing waste copper-based methanol synthesis catalyst to obtain a first powder; Step B, calcining the first powder; Step C, washing and filtering the calcined first powder to obtain a filter cake material; Step D, drying and crushing the filter cake material to obtain a second powder; Step E, adding a molding aid to the second powder and kneading to obtain a semi-finished product; Step F, molding the semi-finished product, and then drying and calcining it to obtain the carbon monoxide catalytic combustion catalyst. This invention turns waste into treasure, utilizing waste methanol synthesis catalyst to obtain a carbon monoxide catalytic combustion catalyst, and has good prospects for widespread application.