573results about How to "High catalytic activity" patented technology

A novel modified conjugated diene polymer is obtained by polymerizing a conjugated diene compound with a specified catalyst consisting of components (a)-(c) and then reacting with at least one specified compound selected from the group consisting of components (d)-(l), and has a content of cis-1,4-bond of not less than 85% and a ratio of weight average molecular weight to number average molecular weight of not more than 4. And also, a rubber composition comprises the modified conjugated diene polymer a rubber ingredient.

The invention discloses a carbon dioxide methanation catalyst and a preparation method thereof. The carbon dioxide methanation catalyst takes an aerogel oxide as a vector, an additive is added, nickel is used as an active component, the additive is alkali metal or alkali earth metal, and the aerogel oxide vector is silicon dioxide, titanium dioxide, zirconium dioxide, aluminum oxide or a compoundthereof. The catalyst comprises the following components in percentage by weight: 5-40wt.% of nickel and 0.01-30wt.% of the additive. The catalyst of the invention has high catalytic activity and stability, and can effectively catalyze carbon dioxide to be hydrogenated into methane at normal pressure under the reaction conditions that the air speed is 2000-20000h<-1>, the ratio of H2 to CO2 is 4:1, and the temperature is 300-500 DEG C. The maximum conversion rate of CO2 is higher than 90% and the maximum selectivity of CH4 is 99.9%. The preparation method of the catalyst of the invention has the advantages of simplicity, easy operation, lower cost and certain application prospects.

The invention discloses a method for preparing a three-dimensional carbon framework embedded nano platinum-based alloy catalyst, and aims to solve the problems that a conventional Pt-based catalyst is low in activity, poor in stability and Pt utilization rate. According to the method, in the growth process of a zeolite imidazolate framework structural material (ZIF), Pt nanoparticles modified by a surfactant are uniformly wrapped in a ZIF structure, the high-temperature reduction process is precisely regulated, the ZIF carbonization, metal reduction and alloying process is controlled, and thus a catalyst structure of a three-dimensional carbon framework embedded nano platinum alloy is constructed. According to the method, the structural shrinkage effect of the carbonization process is smartly utilized, the ZIF structure is converted into a three-dimensional through carbon framework pore structure, the range limiting function of a ZIF framework at high temperature is smartly utilized, platinum particles and metal ions in the ZIF structure are subjected to in-situ alloying and embedded into the framework structure, then the three-dimensional catalyst of a pore-communicated framework and a nano-grade platinum alloy particle embedded structure is formed, the activity and the stability of the catalyst are greatly improved, and the utilization rate of Pt is greatly increased.

The invention discloses a nolybdenum disulfide nanometer particle, a preparation method thereof and an application thereof. The preparation method for the nolybdenum disulfide nanometer particle comprises the following steps: mixing molybdenite or micron-level nolybdenum disulfide with ionic liquid and/or organic solvent to obtain a mixture; grinding and/or ultrasonically processing the mixture; and separating the mixture to obtain the nolybdenum disulfide nanometer particle. The nanometer nolybdenum disulfide provided by the invention has excellent catalytic activity in the hydrodesulfurization reaction, hydrogen evolution reaction and oxidation reaction of methanol. Meanwhile, the nolybdenum disulfide nanometer particle, which is used as a semiconductor nanometer material, has application prospect in photovoltaic conversion and photocatalytic water-splitting. More importantly, the nanometer nolybdenum disulfide has excellent catalytic performances in the oxygen reduction reaction of the nanometer nolybdenum disulfide.

The invention provides a method for preparing an efficient stable fuel cell catalyst and aims to solve the defect that an existing fuel cell catalyst is low in property and poor in stability. The method provided by the invention is characterized in that polyaniline covers the surface of a Pt/C catalyst through using an in-situ chemical oxidation polymerization method, and further an N-doped carbon layer is formed under transition metal salt catalysis through high-temperature pyrolysis; on one hand, the formed N-doped carbon layer is utilized as a second active centre and can strengthen the catalytic activity with Pt synergism, on the other hand, the migration and birdnesting growth of Pt nano particles on the surface of a carbon support are effectively blocked, and the stability of a catalyst is improved; in addition, the nanometer limited range action of the polyaniline can effectively restrain the sintering growth of the Pt nano particles on the surface of the carbon support in the high-temperature processing process, and the high activity specific surface area of a final catalyst is guaranteed; the oxygen reduction activity and the stability of the prepared Pt/C catalyst modified by the N-doped carbon layer are remarkably better than those of a commercialization Pt/C catalyst.

The invention discloses a high-efficiency multi-element transition metal phosphide hydrogen-evolution catalyst and a preparation method thereof. The catalyst is Co<x>Fe<y>P and is formed by being loaded in carbon cloth by a hydrothermal method. The preparation method of the catalyst comprises the following steps of preparing a precursor by the hydrothermal method, adding a certain amount of a mixture of Co(NO<3>)<2>.6H<2>O and Fe(NO<3>)<3>.9H<2>O into deionized water to form an uniform mixed solution, placing the mixed solution in a reaction kettle, adding carbon cloth (CC) as a carrier, uniformly adding strong ammonia water, hermetically heating the mixed solution to 110-120 DEG C, carrying out heat preservation for 9-10 hours, taking out the CC, and drying the CC to obtain the precursor; and carrying out low-temperature phosphorization on the precursor, separately placing NaH<2>PO<2> and the precursor in an upstream and a downstream of a tube furnace, introducing nitrogen or inert gas, heating the tube furnace to 300-350 DEG C, and carrying out heat preservation for over 2 hours to obtain the hydrogen-evolution catalyst. Compared with the prior art, the hydrogen-evolution catalyst prepared according to the method is endowed with high-efficiency and stable catalytic hydrogen evolution capability in an acidic solution, and the hydrogen production cost through electrolysis of water can be reduced.

The invention discloses a silver plating copper powder, a chemical plating liquid and a method of chemical plating; wherein, the silver coating ratio of the silver plating copper powder is 10 to 95%; the silver plating layer comprises 0.5 to 1.2wt% rare-earth metal cerium and/or lanthanum and/or yttrium; the chemical plating liquid comprises three independent components of silver nitrate water solution, formaldehyde ethanol solution and rare-earth nitrate water solution. The method of chemical plating is characterized in that (1) the copper powder is washed and is processed by ultrasonic sensitization and ultrasonic activation in sequence, and (2) the three components of the chemical plating liquid are added in sequence and the ultrasonic chemical plating is processed. The method of chemical plating has the advantages of utilizing the modification effect of rare-earth, raising the stability of plating liquid, the catalytic activity of copper powder surface and the reduction activity of silver ion, adjusting the silver coating ratio from 10% to 95% according to different demands, and even distribution, smooth surface and high conductivity and oxidation resistance of silver plating layer.

The present invention relates to biodiesel oil preparing process, and provides one biodiesel oil preparing process with solid acid and solid alkali as catalyst to lower the activating energy and raise the reaction speed. The biodiesel oil preparing process includes the following steps: reacting dried grease with high free fatty acid content, methanol or ethanol, and cosolvent in the molar ratio of 1 to 6-1 to 6.05 in the first fixed bed reactor with solid catalyst A at 60-65 deg.c for about 3 hr; separating the oil phase from others; reacting the oil phase in the second fixed bed reactor with solid catalyst B with methanol or ethanol and cosolvent at 60-65 deg.c for about 3 hr; distilling out methanol or ethanol and cosolvent; separating the biodiesel oil from glycerin phase; and distilling the biodiesel oil phase to obtain biodiesel oil product. The catalyst of the present invention has high catalytic activity and can lower the activating energy and raise the reaction speed.

The invention discloses a dendritic nanowire catalyst carrier with metal oxide/carbon core-sheath structure and a preparation method of a supported catalyst. The catalyst carrier is dendritic nanowires with the core-sheath structure; according to the core-sheath structure, the metal oxide is adopted as an inner core; and carbon is adopted as an outer sheath. The preparation method comprises the following steps: (1), preparing a uniform and transparent reactant solution; (2), carrying out solvothermal reaction; (3), centrifugally washing and drying the obtained product; and (4), coating the obtained product with a carbon sheath. The dendritic nanowire catalyst carrier with the metal oxide/carbon the core-sheath structure and the preparation method of supported metal nanoparticles disclosed by the invention are simple to operate and easy to control; a template is not needed in the preparation process; ordinary precursors such as chlorate and nitrate can be utilized; a metal organic compound required for preparation of the catalyst with a special structure is avoided; and the cost is further reduced.

The invention relates to a method for synthetising methyl ethyl carbonate by exchange of diethyl carbonate and methanol ester. The method includes that under normal pressure, the diethyl carbonate and methanol are taken as raw materials, imidazolium ionic liquids are taken as catalysts, and synthetic reaction of the methyl ethyl carbonate is performed at a certain reaction temperature and in a certain reaction time. Usage amount of the catalysts only accounts for 1-5% of the mass of the diethyl carbonate, the ionic liquids serving as the catalysts are high in catalytic activity during reaction, the yield of the methyl ethyl carbonate can ultimately reach 68.15%, selectivity can reach 85.39%, the diethyl carbonate can be recovered for continuous cyclic utilization by simple treatment after the reaction, and the methyl ethyl carbonate is long in service life and free of any pollution, so that cost for preparation of the methyl ethyl carbonate is greatly lowered.

The invention is related to catalytic materials and particularly to mesoporous molecular sieves embedded with a zeolite, which are thermally stable at a temperature of at least 900° C., and to a method for the preparation of the catalytic materials. Said catalytic materials are suitable for applications in the field of hydrocarbon processing.

The catalyst consists of loaded vanadium and phosphor oxide and SiO2 carrier formed via pyrogenic decomposition with the loaded amount being 15-58 wt%. It has a V/P atom ratio of 1.2, specific area 117-210 sq m/g, and the main phase being vanadyl pyrophosphate phase. It is used as the catalyst for air oxidizing n-butane to prepare cis-butenedioic anhydride and has one single-path conversion rate of 33-51 % and cis-butenedioic anhydride selectivity of 61-87 % in the typical temperature range of 380-400 deg.c.

This composite oxide powder can secure a large pore volume even after calcination at high temperature and, when a catalyst is formed by loading a noble metal on this composite oxide powder, noble metal grain growth can be suppressed. The composite oxide powder comprises particles of an oxide of a metal M₁ and an oxide of a metal M₂ which does not dissolve in the oxide of the metal M₁, the oxide of the metal M₁ and the oxide of the metal M₂ being dispersed at the nanometer level. Since different oxides serve as a barrier to each other, sintering is suppressed. Therefore, in the case of composite oxide powder comprising Ce as a metal M₁ and Al as a metal M₂, grain growth is small even after exposed to high temperature and pores of 3.5-100 nm secure a volume of 0.07 cc/g or more after calcination at 600° C. for 5 hours and a volume of 0.04 cc/g or more after calcination at 800° C. for 5 hours.

The invention discloses a production method of L-phosphinothricin. According to the method, 2-carbonyl-4-(hydroxymethylphosphonyl)butyric acid is used as a substrate and is catalyzed by an enzyme catalytic system to obtain L-phosphinothricin, and the enzyme catalytic system is composed of gamma-aminobutyric acid/alpha-ketoglutarate transaminase, glutamate dehydrogenase and a coenzyme regeneration system. The method utilizes the advantages of high catalytic activity, strong stereoselectivity and the like of transaminase, and also solves the problem of incomplete transaminase catalytic reaction, so that the catalytic reaction can completely convert the substrate 2-carbonyl-4-(hydroxymethylphosphonyl)butyric acid into L-phosphinothricin, and the conversion rate can reach 100%; no by-product alpha-ketoglutarate is accumulated in the final product of the method, and the residual amount of other substances such as the raw material glutamic acid in the product after the end of the reaction is extremely low, so the subsequent refining process of L-phosphinothricin is greatly simplified, and the total yield of the product is increased.

The object of the present invention is to provide a photobase generator capable of efficiently generating amines (tertiary amines and amidine) high in catalytic activity by sensing light with a wavelength of from 350 to 500 nm (especially, from 400 to 500 nm).

The present invention is a photobase generator characterized in being represented by general formula (1) or (2).

Y⁺ is a quaternary ammonio group of general formula (3) to (5), and X⁻ is a counter anion selected from among a borate anion, a phenolate anion, and a carboxylate anion.

The invention provides a preparation method of a biomass gasified tar cracking composite catalyst, comprising the following steps: first, the preparation of a binder: Ni(NO3)2.6H2O crystal and Al2O3 powder are weighed, the Al2O3 powder is added in the water solution of the Ni(NO3)2.6H2O crystal, immersed for 2h-4h at constant temperature water bath of 40 DEG C, dried into light green powder and calcinated; second, the pretreatment of dolomite: the dolomite is ground into powder of 200 meshes below; third, the preparation of a carrier of the composite catalyst: Fe2O3 and the dolomite powder are mixed uniformly and are added with the binder and 5-20mL of nitric acid to be mixed +-<*> uniformly, and the mixture is extruded to be molded, dried naturally, dried at 105 DGE C, calcinated under 400 DEG C and then calcinated at 900 DEG C; forth, the solution immersion of active components: Ni(NO3)2 ethanol solution is used for immersing the carrier of the composite catalyst, and after dried, the carrier is calcinated at 600-800 DGE C. the composite catalyst has the advantages of high catalytic activity, good strength, practical application and simple process.

The invention discloses a synthetic method and application of a sliver/ferroferric oxide/silicon dioxide/titanium dioxide four-layer nuclear shell structure. The synthetic method of the sliver/ferroferric oxide/silicon dioxide/titanium dioxide four-layer nuclear shell structure comprises the steps of firstly preparing a sliver/ferroferric oxide nuclear shell structure by using a solvothermal method; then preparing a sliver/ferroferric oxide/silicon dioxide three-layer structure on the basis of the nuclear shell structure by using a stober method; coating a layer of burr shape titanium oxide composed of nanosheets on the surface of the three-layer structure obtained in the step B by using the solvothermal method to obtain a sliver/ferroferric oxide/silicon dioxide/titanium dioxide (AgFe3O4SiO2TiO2) four-layer nuclear shell structure. The four-layer nuclear shell structure is good in absorption characteristic, photocatalytic performance and superparamagnetism for removal of organic pollutants or heavy metal pollutants, so that the treatment effect of the organic pollutants and the heavy metal pollutants in sewage can be greatly improved.

The invention discloses a preparing method of ortho-phthalic anhydride, which is characterized by the following: choosing ortho-xylene and naphthalene as raw material; proceeding gas phase catalytic oxidation reaction; adopting two-phase, three-phase bed or four-phase bed V-Ti type accelerant; setting the accelerant as carrier material; coating catalytic activity matter with vanadic oxide and titanium oxide on the carrier; choosing compound from free alkali metal, Sb, P and Nb; adding as catalyst promoter. This invention can modify composite of the reacting rear gas, which can be used to organic chemical industry domain.

The invention relates to a method for preparing ZSM-5 zeolite molecular sieve with a multistage pore structure, its product and a purpose thereof, more specifically, the ZSM-5 zeolite molecular sieve with the multistage pore structure employs a gemini cationic surfactant as a meso-structure guiding agent, and is obtained through a hydro-thermal synthesis method under alkaline condition. According to the invention, the total specific surface area of the ZSM-5 zeolite molecular sieve is 240-1000m<2>.g<-1>, the total pore volume is 0.30-1.40cm<3>.g<-1>, the service life of the ZSM-5 zeolite molecular sieve used as a catalyst in a methanol-to-olefins (MTO) can be greatly prolonged, and can be used in other fields such as coal chemical, petroleum chemical catalysis, natural gas conversion, adsorption and separation.

The invention relates to a catalyst for hydrogen production reaction by hydrazine decomposition at the room temperature, and a preparation method of the catalyst, in particular to a single-active center and double-active center catalyst prepared by taking nickel-containing hydrotalcite as a precursor, and a preparation method of the catalyst. The catalyst comprises X/ M-N, wherein the load capacity of precious metal X (Pt, Ir, Rh, Au, Pd or Ru) is 0-30wt%, the load capacity of metal M (Ni, Co, Mg or Cu) is 10-80wt%, and N (Al, Fe or Mn) is oxide. The catalyst has the characteristics of being high in reaction activity and good in selectivity, and leads hydrazine to be quickly decomposed at the room temperature so as to prepare hydrogen, wherein the highest selectivity reaches 100%. The invention also provides a method for preparing clean hydrogen which does not contain CO. The catalyst is easy in obtaining of raw materials and simple in technology, thus having good application prospect.

Provided is a process for producing a fuel cell electrode catalyst having high catalytic activity which uses a transition metal, e.g., titanium, which process comprises thermal treatment at relatively low temperature, i.e., not including thermal treatment at high temperature (calcining) step. The process for producing a fuel cell electrode catalyst comprises a step (1) of mixing at least a transition metal-containing compound, a nitrogen-containing organic compound and a solvent to provide a catalyst precursor solution; a step (2) of removing the solvent from the catalyst precursor solution; and a step (3) of thermally treating a solid residue obtained in the step (2) at a temperature of 500 to 1100° C. to provide an electrode catalyst; wherein the transition metal-containing compound is partly or wholly a compound comprising at least one transition metal element (M1) selected from the group 4 and 5 elements of the periodic table as a transition metal element.

The invention discloses a method for synthesizing a citric acid ester type compound, which belongs to the technical field of chemical synthesis. The method comprises the following steps of: using citric acid and fatty alcohol as main raw materials, and using benzene sulfonic acid or amino benzene sulfonic acid as a catalyst; and performing esterification and the purification processes of acetylation, neutralization, washing, drying, distillation and the like. The catalyst has rich sources, a low cost and high activity, can be separated from an esterification liquid easily after the neutralization, is coke-free during the distillation, has less corrosion to equipment, and is safe and environment-friendly; the water generated by the esterification is separated out by adopting a binary heterogeneous separation technique, and no water separating agent is additionally added; and acetyl citric acid ester is produced by adopting an esterification-acetylation continuous synthesis method, the flow is greatly simplified, and a synthesis process is shortened. The citric acid ester prepared by the method has the advantages of high quality, high purity, low degree of color and wide applicationrange.

The invention discloses an iron-cobalt-nickel-copper-based high-entropy alloy water electrolysis catalytic material and a preparation method thereof, and belongs to the technical field of composite material preparation. The water electrolysis catalytic material is composed of a reaction active matter and a carrier, wherein the reaction active matter is iron-cobalt-nickel-copper-tin, iron-cobalt-nickel-copper-manganese, iron-cobalt-nickel-copper-vanadium and other iron-cobalt-nickel-copper-based high-entropy alloy nanoparticles, and the carrier is a carbon nanofiber material prepared through anelectrostatic spinning method. The prepared water electrolysis catalytic material has a high specific surface area, diffusion of electrolytic solution and desorption of gas are facilitated, hydrogenand oxygen can be produced under an alkaline condition, and the hydrogen production rate under high voltage is far higher than that of a 20% Pt/C electrode; and carbon nanofibers can effectively protect the high-entropy alloy nanoparticles from being eroded by an electrolytic solution, so that the catalytic material is endowed with good stability.

The invention discloses a Pt/MoS2 nano catalyst and a preparation method and application thereof. The Pt/MoS2 nano catalyst is prepared from MoS2 nano sheets and Pt atoms independently loaded on the surfaces of the MoS2 nano sheets. The Pt/MoS2 nano catalyst is built up by loading the platinum single atoms lonely on the substrates of the molybdenum sulfide nano sheets, not only a heterogeneous structure is achieved so that the catalyst can be easily separated, collected and recycled from a reaction system, but also the Pt/MoS2 nano catalyst can have very high catalysis activity in catalyzing hydrogenation of carbon dioxide based on the high-efficiency atom utilization rate of the single atoms, the high metal substrate mutual action and the synergistic effects of adjacent single atoms.

The invention provides a catalyst ingredient for olefin polymerization, its preparation method and application. The ingredient comprises at least one organic magnesium compound, at least one liquid titaniferous compound, at least one hydroxyl compound, at least one chlorine-containing organosilicon compound, and at least one reaction product of a forming and precipitating aid, wherein, the forming and precipitating aid is a polystyrene block polybutadiene polymer. The prepared catalyst has good hydrogen regulation performance, good particle shape and distribution, which is advantageous for the use of the catalyst in gas phase, slurry and other polymerization devices.

The invention provides a low-temperature hydrolysis method for removing carbonyl sulfide in liquefied petroleum gas. The method comprises the following steps: mixing the liquefied petroleum gas after amine washing with an alcohol amine solution, and performing hydrolysis reaction under the action of a carbonyl sulfide hydrolysis catalyst to remove carbonyl sulfide and hydrogen sulfide in the liquefied petroleum gas and hydrogen sulfide generated by hydrolysis; separating the liquefied petroleum gas from the alcohol amine solution, then washing with water to obtain the refined liquefied petroleum gas and recycling the alcohol amine solution, wherein the adding amount of the alcohol amine solution is 0.1%-20% of the weight of the liquefied petroleum gas. By adopting the low-temperature hydrolysis method for removing carbonyl sulfide in the liquefied petroleum gas provided by the invention, carbonyl sulfide and hydrogen sulfide in the liquefied gas can be removed in one step under the condition of 10-60 DEG C, the step of removing hydrogen sulfide in a conventional process is eliminated, the process is simple, the activity of the catalyst is high, the service life is long and the conversion rate of carbonyl sulfide is above 97%.

The invention discloses a method for synthesizing PODE through condensation, oxidation, polycondensation and etherification of methyl alcohol. The method includes the steps that firstly, methylal with the mass purity of 85%-99.9% is prepared through a reaction of the methyl alcohol and diluted methanal; secondly, the methylal and air are catalyzed and oxidized by iron-molybdenum catalysts to prepare methanal with the mass purity of not less than 70%; thirdly, the methanal is subjected to polycondensation and then is refined to obtain triformol with the mass purity of not less than 99.9%; fourthly, the methylal and the triformol are subjected to etherification, reactive distillation and dehydration and are refined to obtain PODE3-8 with the mass purity of over 99%. By the adoption of the method, the single-pass yield of the PODE is increased from 40%-50% to 95%, the yield of the PODE3-8 is increased from 20% to 90%, product distribution is more reasonable, and the product purity is improved from 50% to 99%. The PODE is wide in application prospect and remarkable in economic, social and environmental benefit.

A carried silver catalyst for preparing anhydrous formaldehyde by directly dehydrogenating methanol is prepared by sol-gel method, which includes such steps as mixing ethyl n-silicate with the solution containing soluble Mg salt, dropping it in aqueous solution of inorganosilver salt, generating colloid, aging, drying and calcining. Its advantages are high activity, long service life and low cost.

The invention discloses a preparation method for a metal sulfide catalytic electrode and application thereof. According to the invention, metal element or any one form or more than one form of metal sulfide is resolved in hydrazine together with a sulfur element or together with any one form or more than one form of sulfur ammonium salt or sulfur hydrazonium salt, thereby forming a NH4 or N2H5 kation; the metal and the sulfur element form a precursor solution of an anion; the precursor solution is coated on the transparent conductive substrate; and the obtained transparent conductive substrate adsorbing the precursor is subjected to heating and annealing processing, thereby obtaining the metal sulfide catalytic electrode.

The invention discloses a method for preparing a graphene thin film by chemical vapor deposition at normal pressure and low temperature. According to the method, a metal substrate is subjected to high-temperature annealing treatment firstly and then temperature-reduction annealing treatment; and next, the graphene thin film is obtained on the surface of the metal substrate through the chemical vapor deposition method. By virtue of the method, the catalysis activity of the metal substrate is improved, so that the growth temperature of graphene is lowered, and the energy consumption and cost of industrial production of the graphene thin film are lowered consequently; and compared with a conventional chemical vapor deposition method for synthesizing the graphene thin film, the method disclosed by the invention is simple in process, the carbon source is wide in source, the prepared graphene thin film is high in quality, and the number of layers is uniform and controllable.