760 results about "Active center" patented technology

The invention is applicable to the technical field of biological detection, provides a fluorescence immunochromatography detection method based on monatomic nano-enzyme enhancement, and particularly relates to two application forms: in the first form, a detection signal enhanced fluorescence immunochromatography detection card and a sample diluent containing a monatomic nano-enzyme are involved; in the second form, the invention relates to a fluorescence immunochromatography detection card with enhanced detection signals, and a sample pad of the detection card is obtained by soaking a sample pad treatment solution containing a monatomic nano-enzyme solution. The two application forms both relate to a monatomic nano-enzyme solution, and the solution is composed of monatomic nano-enzyme, bio-enzyme composite microspheres, a protective agent, a surfactant, a thickening agent and a preservative. The monatomic nano enzyme is composed of an atomic-scale dispersed metal active center and a carrier material. When the method is used for detecting myocardial and inflammatory markers, the limit of quantitation can reach the pg / mL level, the detection linear range can span three orders of magnitude, and the clinical examination use requirements can be met. The kit can be applied to rapid quantitative detection of myocardial and inflammatory markers, has the advantages of high sensitivity, rapidness, convenience and high efficiency, and provides an auxiliary diagnosis basis for early screening of myocardial infarction, heart failure and infection related diseases.

The invention discloses a carbon nitride-based composite material as well as a preparation method and application thereof. The carbon nitride-based composite material comprises a non-metal doped carbon nitride carrier and a noble metal, wherein the noble metal exists in the carrier in an element doping form and / or is loaded on the carrier in an oxide form; the precious metal is one or more of Pt, Pd, Au and Ru, and the nonmetal is one or more of P, S and I. According to the carbon nitride composite material disclosed by the invention, noble metal is utilized to modify carbon nitride, the number of surface active sites is increased, the electron and chemical structures of an active center are adjusted, and meanwhile, generation and migration of photo-generated charges are promoted. Meanwhile, the surface of the carbon nitride composite material is modified by non-metallic elements, so that adsorption and activation of reactant H2O molecules are effectively promoted. The catalyst disclosed by the invention is simple in preparation process, good in repeatability and easy for large-scale production.

The invention discloses an enzyme immobilization method based on charge directed crosslinking, and belongs to the technical field of enzyme immobilization. The method sequentially comprises the following steps: reacting an enzyme with a modifier containing an anionic group to generate an electronegative modified enzyme; dissolving a protonated amino carrier in an acidic buffer solution to form a first solution, and dispersing a dissociation anion group-containing carrier and a modification enzyme in an alkaline buffer solution to form a second solution; mixing the two solutions, and constructing a gel network immobilized enzyme through electrostatic crosslinking; and finally, strengthening the gel network by using a multivalent metal ion solution. Directional anchoring of the enzyme in the gel is achieved through charge matching, the network stability and the enzyme microenvironment are synchronously optimized in combination with metal ion coordination, use of a covalent cross-linking agent is avoided in the whole process, conformation damage of an enzyme active center is avoided, the activity retention rate, the operation half-life period and the substrate mass transfer efficiency of the immobilized enzyme are remarkably improved, and the immobilized enzyme has good application prospects. The method is suitable for efficient immobilization of industrial enzymes such as beta-glucosidase, and has high biocompatibility and industrial potential.

The invention belongs to the technical field of biological medicine, and particularly relates to application of anethomycin in preparation of medicine for inhibiting cysteine protease activity. The invention discovers that anethomycin has the function of inhibiting the activity of virus cysteine protease, especially 3C or 3CL protease, for the first time. Molecular docking proves that anethomycin can effectively bind to the catalytic activity center of Senecavirus (SVA) 3C protease. An in-vitro FRET enzyme activity experiment proves that the inhibition rate of 50 [mu] M of anethomycin on SVA 3C protease reaches up to 88.5%. Cellular level experiments show that the anethomycin can significantly inhibit replication of SVA viruses, shows broad-spectrum antiviral activity on various viruses such as encephalomyocarditis viruses (EMCV), porcine reproductive and respiratory syndrome viruses (PRRSV) and porcine deltacoronaviruses (PDCoV), and is low in cytotoxicity and high in selectivity index (SI).

The invention discloses a magnesium oxide supported catalyst, a preparation method and application in VOCs (volatile organic compounds) purification, and belongs to the field of volatile organic compound catalytic purification. Magnesium oxide is used as a carrier of the catalyst, and two modified materials are supported, one is a double-active-center material anchoring nickel single atoms and ruthenium clusters in a porous carbon-nitrogen framework, and the other is a double-active-center material anchoring nickel single atoms and ruthenium clusters in a porous carbon-nitrogen framework; and the other one is a defective carbonitride MXene intercalated hydroxyapatite nanosheet, and lanthanum oxide can be added as a cocatalyst. The preparation method comprises the following steps: sequentially loading the two modified materials on the magnesium oxide carrier, and carrying out ultrasonic dispersion, stirring, centrifuging, drying, calcining and the like, so that the active component and the carrier form strong interaction. According to the catalyst, through the synergistic effect of double active centers and the structural advantages of the modified material, the catalytic oxidation efficiency and stability of VOCs are remarkably improved, and the catalyst is suitable for purification treatment of industrial waste gas and volatile organic compounds in indoor air.

The invention relates to the technical field of organic synthetic chemistry, in particular to a preparation method of ethyl 2-n-butyl acetoacetate, which comprises the following specific steps: S1, preparation of a composite solid base catalyst, S2, synthesis of ethyl 2-n-butyl acetoacetate, S3, post-treatment of a reaction solution, and S4, separation and purification of a product. The preparation method has the following beneficial effects that the magnesium-aluminum composite oxide is used as a carrier, and the composite solid base catalyst loaded with potassium and lanthanum has relatively high catalytic activity and selectivity; the magnesium-aluminum composite oxide carrier has a relatively large specific surface area and rich alkaline sites, so that a good catalytic environment is provided for the reaction; as a main active component, potassium ions can effectively activate alpha-active methylene of ethyl acetoacetate and promote formation of negative ion intermediates; the introduction of lanthanum ions can adjust the electronic structure of the catalyst, enhance the stability of the active center and inhibit the occurrence of side reactions.

The invention discloses a tetrathiomolybdate intercalated ternary iron-magnesium-zinc layered double hydroxide catalyst, a preparation method thereof and an application of the tetrathiomolybdate intercalated ternary iron-magnesium-zinc layered double hydroxide catalyst in degrading azo dyes by activating peroxymonosulfate. According to the method, a carbonate intercalated ternary LDH precursor is synthesized through a hydrothermal reaction, interlayer anions are replaced with nitrate and tetrathiomolybdate through ion exchange, and the target catalyst is obtained. In the catalyst, a unique Fe-Mg-Zn ternary metal laminate and a MoS < 2-> intercalation structure cooperatively construct a multi-active center, and MoS < 2-> is used as an electron donor to promote cyclic regeneration of Fe < 3 + > / Fe < 2 + >. The catalyst keeps ultrahigh activity in a wide range of pH (potential of hydrogen) of 3-9, can completely degrade 10 mg / L of acid orange 7 within 5 minutes, and is stable in structure and low in metal dissolution risk. The problems of low activity, slow Fe < 3 + > reduction, metal ion dissolution and the like under neutral and alkaline conditions in an advanced oxidation technology based on peroxymonosulfate are solved, and the method has important application value in the field of printing and dyeing wastewater treatment.

The invention belongs to the technical field of catalyst preparation, and particularly relates to a method for synthesizing a fly ash-based hierarchical porous ZnY / Si-Beta catalyst by adopting a solvent-free method and application of the fly ash-based hierarchical porous ZnY / Si-Beta catalyst. According to the invention, fly ash is taken as a raw material, the ZnY / Si-Beta catalyst is synthesized by adopting a solvent-free method to catalyze direct conversion of an ethanol aqueous solution to prepare butadiene, so that resource utilization of fly ash can be realized, the influence of water on the active center of the catalyst can be inhibited, and efficient conversion of the ethanol aqueous solution to prepare butadiene is realized.

The invention discloses chain end modified liquid rubber, mixed rubber, a preparation process, a tire and a vehicle, and belongs to the technical field of liquid rubber and manufacturing thereof. According to the liquid rubber, butadiene monomers and a chain transfer agent are added in batches in the preparation process, negative ion active centers are frequently transferred to the chain transfer agent from the tail end of a polybutadiene-based lithium active chain to form new initiation growth centers, then newly introduced butadiene monomers are initiated to grow, the dosage of an n-butyllithium initiator is remarkably reduced, and the stability of the liquid rubber is improved. The production cost is greatly reduced, the generation of sewage is greatly avoided, the monomer concentration of the final rubber product can reach about 80 percent by weight, the productivity is improved, and large-scale production is facilitated; the rubber also enables the filler to have good dispersibility, and has good compatibility with base rubber such as styrene butadiene rubber, natural rubber and the like.

The invention discloses a cascade catalyst and a preparation method and application thereof, and belongs to the technical field of catalysts. The cascade catalyst comprises a carrier and an active component, the carrier is at least one of a carbon carrier, a metal oxide carrier, a semiconductor and an organic framework material; the active components are at least two of noble metal, non-noble metal and nonmetal with catalytic action; wherein the active components are uniformly dispersed on the carrier. And the active component accounts for 0.001-50% of the cascade catalyst in percentage by mass. An active component and / or a carrier in the cascade catalyst are / is modified with an oxygen-containing functional group; and the surface area of the carrier is greater than or equal to 200 cm < 2 > / g. By optimizing the selectivity and activity of the catalyst in each step and the compatibility of reaction conditions, side reactions and energy loss are reduced. The distribution form of the cascade catalyst comprises single atoms, sub-nano clusters, nano-particles and the combination of the three, and the limitation of a single type of active centers is broken through through the synergistic effect.

The invention discloses a molecular sieve catalyst for synthesizing methyl ethyl carbonate by a transesterification method and a regeneration method, and relates to the technical field of molecular sieve catalysts, the molecular sieve catalyst comprises a microporous double-active-center inner core and an amphoteric mesoporous shell; the microporous double-active-center core takes the X-type zeolite as a carrier to load potassium, cesium, lanthanum and barium; the amphoteric mesoporous shell is an MCM-41 and SBA-15 composite mesoporous silica layer coating the outer part of the inner core and has a double-mesoporous structure, amino propyl triethoxy silane and carboxyethyl triethoxy silane are grafted on the surface of the amphoteric mesoporous shell, and zirconium and titanium are co-doped. According to the invention, collaborative optimization of active centers and mass transfer channels is realized through a core-shell structure of a microporous double-active-center core and an amphoteric mesoporous shell. The activity and selectivity of catalytic transesterification are remarkably improved by the microporous core; due to the double-mesoporous structure and surface functional modification of the amphoteric mesoporous shell, the mass transfer efficiency of reactants and products is improved, and the adaptability of the catalyst to a reaction system is enhanced.

The invention relates to the technical field of hydrodesulfurization catalysts, and discloses a molecular sieve hydrodesulfurization catalyst and a preparation method thereof.Active Si-Cl bonds of maleate methyl dichlorosilane react with hydroxyl in an MCM-41 molecular sieve, then hydrolysis is conducted through sodium hydroxide, and therefore a large number of carboxyl groups are grafted in the molecular sieve; carboxyl can form a strong coordination effect with metal ions such as nickel and the like, so that nickel and molybdenum are uniformly adsorbed into a matrix of the molecular sieve, a nickel-molybdenum oxide catalytic active center is uniformly generated in the molecular sieve through high-temperature roasting, catalytic sites are not easy to agglomerate, the dispersity is good, and the catalytic activity is stable. The catalyst can effectively perform hydrogenation reaction on sulfur-containing substances such as thiophenes in straight-run diesel oil, and has higher desulfurization rate. The catalyst has good practical application in the aspects of oil hydrodesulfurization catalysis and the like.

The invention discloses a Pd-Ba / C catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: step 1, pretreating a carbon carrier; step 2, preparing a complexing solution containing a barium complex; step 3, carrying out wet impregnation to obtain a carbon carrier adsorbed with a barium complex; 4, performing low-temperature pyrolysis to obtain a barium pre-modified carrier; 5, a complexing solution containing palladium and barium complexes is prepared; step 6, co-adsorption of bimetals is realized through wet impregnation, and a bimetal adsorption carrier is obtained; step 7, freeze drying; 8, the precursor obtained after freeze drying is subjected to hydrogen reduction, and the Pd-Ba / C catalyst is obtained. The invention provides application of the Pd-Ba / C catalyst in preparation of ethylene by hydrodechlorination of 1, 2-dichloroethane. According to the invention, pre-loaded barium occupies a strong adsorption site on the surface of the activated carbon, so that the stability and dispersity of a palladium active center can be enhanced, and synergistic improvement of chlorine poisoning resistance and catalytic performance of the catalyst is realized.

The invention provides a non-metallocene catalyst as well as a preparation method and application thereof, the molecular structure of the non-metallocene catalyst is as shown in formula 1: in the formula 1, R1 and R2 are independently one of H, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl and tert-butyl. The non-metallocene catalyst provided by the invention has an open space structure and a multi-metal active center, and can catalyze butene-1 to generate a polymerization reaction with high activity, so that a bimodal wide-distribution polybutylene product is prepared.

The invention discloses a tumor targeting boron-containing Fe3O4-based nano-enzyme and a preparation method and application thereof, and belongs to the technical field of tumor treatment.The tumor targeting boron-containing Fe3O4-based nano-enzyme takes boron-10 doped Fe3O4 nano-enzyme as a boron-containing drug group and an enzyme activity center, and the surface of the tumor targeting boron-containing Fe3O4-based nano-enzyme is modified with a targeting group; the targeting group is chitosan-folic acid-polyethylene glycol. The tumor targeting boron-containing Fe3O4-based nano-enzyme has relatively strong selective enrichment capacity on tumor cells such as melanoma, shows good biocompatibility and low toxicity, and has relatively strong apoptosis induction and killing effects on the melanoma cells in boron neutron capture therapy; meanwhile, active oxygen free radicals can be generated in boron neutron capture therapy to generate an oxidative damage effect.

The invention relates to the technical field of bioengineering, in particular to a process for continuously producing nicotine based on immobilized enzyme. The immobilized microbial agent comprises a composite carrier, an engineering strain and an immobilized auxiliary agent, in the process for continuously producing nicotine based on immobilized enzyme, amine oxidase of an engineering strain is subjected to site-specific modification, so that spatial structure deformation when the amine oxidase is combined with a carrier is reduced, and a three-dimensional network structure of hydroxyethyl chitosan-guar gum composite microspheres in the composite carrier is matched to provide an adaptive microenvironment; the activity loss of enzyme molecules caused by steric hindrance or structural change is reduced; in the immobilization auxiliary agent, gallic acid and an enzyme molecule sulfydryl form a coordinate bond to maintain an active center conformation, glutaraldehyde and polyethyleneimine enhance the binding stability through a crosslinking effect and charge regulation, and the maintaining effect of enzyme activity during continuous production is improved, so that the enzyme activity loss in the immobilization process is reduced, and the immobilization efficiency is improved. The stability of the enzyme in long-term continuous reaction is enhanced.

The invention relates to the technical field of environmental catalysis and pollution treatment, in particular to a chelated iron desulfurizer. According to the desulfurizer, DOTA is used as a core chelating agent, an iron active center is accurately anchored to a shell layer of a polymer core-shell structure microsphere through a multi-step polymerization and functionalization process, and the design of solution-state complexing iron is assisted, so that the desulfurizer has both solid-phase localization and solution compensation, the capability of resisting poisoning of impurities such as cyanide and mercaptan is remarkably improved, and iron loss is reduced. The desulfurizer is high in desulfurization efficiency and large in sulfur capacity, can stably operate for a long period, shows excellent continuous activity and selectivity under the conditions of coexistence of various impurities and repeated regeneration, and has a good application prospect.

The invention discloses a bimetallic asymmetric reduction Schiff base catalyst for synthesizing ethylene carbonate and a preparation method of the bimetallic asymmetric reduction Schiff base catalyst. According to the catalyst, a diamine compound is subjected to selective single-side protection, the imine reduction position is controlled, and a bimetallic active center is introduced; the controllable synthesis of a product for reducing the outer side imine and a product for reducing the inner side imine is realized; the obtained product is recrystallized to obtain a monoimine-monoamine type ligand with a clear asymmetric structure, the monoimine-monoamine type ligand and metal salt form a bimetallic catalyst, and the catalyst generates a synergistic effect through double active sites and shows high catalytic activity and excellent product selectivity.

The invention provides a manganese-based tandem catalyst as well as a preparation method and application thereof. The manganese-based tandem catalyst comprises a reverse water gas shift catalytic unit (CO2 + H2-CO) and a Fischer-Tropsch synthesis catalytic unit (CO + H2-CxHyOz), which are called MnO-FTS system for short, the active center of the reverse water gas shift catalytic unit is MnO; the Fischer-Tropsch synthesis catalytic unit comprises any one of a Cu / ZnCr-based catalyst, a FeNaAl-based catalyst, a Ni / SiO2 catalyst and a Co / SiOO catalyst. By constructing a novel efficient and synergistic MnO-FTS catalyzing system, directional conversion from COhydrogenation to liquid fuel is achieved, meanwhile, side reactions prone to occurring in direct COhydrogenation are avoided, and the overall reaction efficiency and product selectivity are improved.

The application provides a bifunctional composite film of multi-guest molecule synchronous gas phase coordination deposition, metal precursors and organic ligands are dissolved in an organic solvent, a porous inorganic substrate is immersed in the organic solvent, and a substrate loaded with a MOF layer is obtained through a hydrothermal reaction; the substrate loaded with the MOF layer, nitrogen-containing organic ligands and an organic metal compound are placed in a closed container, a MOF composite film with metal nanoparticles is obtained through gas phase deposition, and the MOF composite film is calcined at 160-240 DEG C for 1-4 hours to obtain the bifunctional composite film of multi-guest molecule synchronous gas phase coordination deposition; through molecular level design, the catalytic active center is firmly anchored in the separation matrix, and the problem that the active component is prone to loss is solved. The prepared composite film has excellent oil-water separation performance and efficient photo-Fenton catalytic degradation capacity, and provides an innovative material solution for advanced water treatment.

The application discloses a P and O co-doped FeNiRuOx nano catalyst and a preparation method and application thereof, relates to the technical field of electrocatalytic materials, and the catalyst takes Fe, Ni and Ru as metal active centers, reconstructs a surface electronic structure through P and O double anion co-doping, and forms a polygonal nano structure, wherein the mass fraction ranges of Fe, Ni, Ru and P are 5.0-6.0%, 75-78%, 11-12% and 6.5-7.0% respectively. The preparation method comprises the following steps: taking iron acetylacetone, nickel acetylacetone and ruthenium chloride trihydrate as metal sources, synthesizing a precursor through a solvothermal reaction, and realizing P and O co-doping through a sodium hypophosphite assisted solid-phase phosphorization process, and the preparation process is mild. The synthesized catalyst has unique structural advantages, the formed polygonal nano structure has a large specific surface area and rich grain boundary defects, more active sites are exposed, and convenient channels are provided for the mass transfer of reactants and products. The synergistic effect among the polymetals further enhances the catalytic performance.

The invention belongs to the technical field of carboxylic ester preparation, and particularly relates to a preparation method of dioctyl terephthalate, which comprises the following steps: under the catalysis of acid, modifying mesoporous silica by using OTES and a carbazole silane solution to obtain modified silica; under the protection of inert atmosphere, uniformly mixing TBT and methylbenzene, adding absolute ethyl alcohol for reaction, adding modified silicon dioxide for dispersion, adding water-containing mixed liquid for reaction, and aging, filtering, washing and drying to obtain the titanium-based catalyst. The preparation method comprises the following steps: uniformly mixing PTA, 2-ethylhexanol and a titanium-based catalyst, carrying out heating reaction, filtering, and carrying out reduced pressure distillation to obtain the dioctyl terephthalate. The method can inhibit hydrolysis failure of a titanium active center in the catalytic esterification reaction process, and improves the yield and purity of dioctyl terephthalate.

This invention relates to the field of catalyst technology, specifically to a latent epoxy resin curing catalyst with precisely controllable activity and its preparation method. The catalyst is 1-(2-(N-tert-butyl-N'-phenylurea)ethyl)-3-(2-(phenyldithio)ethyl)imidazolium, which simultaneously possesses an imidazolium ring catalytic active center, a thermally hindered urea bond, a temperature-responsive dynamic disulfide bond, and an intramolecular hydrogen bond unit. Precise control of catalytic activity is achieved through the synergistic effect of these triple dynamic bonds. The catalyst exhibits excellent storage stability at room temperature, rapid curing at activation temperature, and is free of metal ions. The cured epoxy resin exhibits good dielectric properties. This invention's catalyst achieves a balance between excellent latency and rapid curing performance through the synergistic control of these triple dynamic bonds. It possesses excellent dielectric and mechanical properties, can be compounded with various curing agents, and its preparation method is simple and easy for industrial production.

The invention relates to the technical field of oxygen reduction catalysts, in particular to a transition metal-based triatomic oxygen reduction catalyst and a preparation method and application thereof. The invention relates to a preparation method of a transition metal-based triatomic oxygen reduction catalyst. The preparation method comprises the following steps: dispersing carbon nanotubes in a solvent to obtain a dispersion liquid; adding transition metal acetate, urea and 4, 4 '-dihydroxy [1, 1'-biphenyl]-3, 3 ', 5, 5'-tetracarboxaldehyde into the dispersion liquid, performing ultrasonic treatment to obtain mixed liquid, and then performing heating reaction in an inert atmosphere; and after the reaction is finished, naturally cooling to room temperature, filtering, washing and drying to obtain the transition metal-based triatomic oxygen reduction catalyst. The catalyst designed by the invention not only has an efficient catalytic active site, but also remarkably improves the material transmission efficiency and enhances the utilization rate of a catalytic active center by optimizing the structure of a composite material, so that the synergistic enhancement of the electro-catalytic performance is realized.

This invention provides a polynuclear metal cluster based on salicylaldehyde acetal-2-thiophenol ligand, its preparation method, and its application. The chemical formula of the polynuclear metal cluster is Co4(C 13 H9NOS)6·2CH3CN·CH3OH, where C 13 H9NOS is salicylaldehyde acetal-2-thiophenol, with Co forming a six-coordinate octahedral configuration with N, O, and S. The salicylaldehyde acetal-2-thiophenol ligand in the polynuclear metal cluster of this invention can effectively stabilize the active center of metallic cobalt, resulting in a polynuclear metal cluster with significant OER activity and broad prospects for practical applications.

The invention relates to the technical field of photocatalytic hydrogen production, and provides a TNM-Fe-Co II type heterojunction catalyst as well as a preparation method and application thereof in photocatalytic hydrogen production. The TNM-Fe-xCo photocatalytic material is prepared through ion doping and TiO2 compounding strategies: firstly, through a metal ion co-doping strategy, Co < 2 + > is introduced into an NH2-MIL-Fe skeleton to construct a bimetallic active center, so that not only is an additional active site provided, but also compounding of photo-induced carriers is inhibited through a unique metal-metal charge transition (MMCT) process, and the photocatalytic performance of the photocatalytic material is improved; therefore, the photocatalytic performance is improved; tiO2 is further compounded, and the separation of photon-generated carriers is enhanced through the construction of heterojunction, so that the photocatalytic activity is improved. The composite material has excellent hydrogen production performance under the condition of no noble metal auxiliary agent, shows excellent performance and wide application prospect of the composite material in the field of photocatalysis, and provides a new design strategy for development of high-performance photocatalysts.

The application relates to the technical field of organic silicon synthesis, and particularly discloses a high-selectivity platinum catalyst and a vinyl double-seal head synthesis method. The high-selectivity platinum catalyst comprises a carrier and a platinum active component loaded on the carrier, the platinum active component is obtained by reducing and activating a platinum precursor and a ligand under a hydrogen atmosphere at 250-350 DEG C after coordination modification, and the molar ratio of the ligand to the platinum element in the platinum precursor is 2-3:1. In the application, the platinum active component is obtained by reducing and activating the platinum precursor and the ligand after coordination modification, and the ligand and the platinum element form a specific coordination structure of the platinum active center, guide the direct silicon-hydrogen addition reaction of acetylene and a hydrogen-containing double-seal head, thus the dimethyl chlorosilane intermediate is not needed, the process flow is simplified, and the effects of improving the reaction yield, environmental protection and process economy are achieved.

This application discloses a cyclic GMP-AMP synthase mutant. Compared to the wild-type cyclic GMP-AMP synthase shown in SEQ ID NO.1, the amino acid sequence of the cyclic GMP-AMP synthase mutant has any one of the following mutations: L377M or H437T / S434T. Specifically, the amino acid sequence of the L377M mutated cyclic GMP-AMP synthase mutant is shown in SEQ ID NO.4, and the amino acid sequence of the H437T / S434T mutated cyclic GMP-AMP synthase mutant is shown in SEQ ID NO.9. The cGAS mutant of this application exhibits four times the activity of the wild-type. The preparation method uses readily available and economical raw materials, is simple to operate, environmentally friendly, and pollution-free, with high synthesis efficiency, making it suitable for industrial development.

The invention discloses an epoxy-ring-opening bifunctional catalyst and a preparation method and application thereof, and belongs to the technical field of catalyst materials and biomass chemical engineering, the catalyst takes a mesoporous molecular sieve SBA-15 as a carrier, tungsten and molybdenum active components are combined with an aluminum-doped silicon-based framework through co-assembly and a hydrothermal method, and the mesoporous molecular sieve SBA-15 is prepared into the epoxy-ring-opening bifunctional catalyst. The total loading amount of tungsten and molybdenum is 10wt% of the mass of a silicon source, the molar ratio of W to Mo is (3: 7)-(7: 3), and the molar ratio of silicon to aluminum is (10-30). The preparation method comprises the following steps: self-assembly of a template agent, co-hydrolysis of a silicon-aluminum source and a tungsten-molybdenum source, hydrothermal crystallization, temperature programming calcination and the like. The catalyst is applied to preparation of biomass polyol from methyl vegetable oleate by one-pot epoxy-ring opening, and epoxidation and ring opening reactions are simultaneously realized under mild conditions. The polyol obtained by the invention has the characteristics of low viscosity, low acid value and high hydroxyl value.