293 results about "Platinum based catalysts" patented technology

The invention relates to a catalyst for preparing propylene through propane catalytic dehydrogenation, which is a load type platinum-based catalyst and is characterized in that home-made mesoporous molecular sieves MCM-41 are used as carriers, metal Pt is used as an active ingredient, and metals Sn, Sn-Ce or Sn-Ce-Ca are used as auxiliary agents. In a preparation method, an isovolumetric continuous immersion method is adopted for preparation. The catalyst and the preparation method have the advantages that the isovolumetric continuous immersion method is adopted for preparing multi-component catalysts, wherein the content of any one component is easy to control, the prepared catalyst has higher specific surface area (700 to 900m<2> / g) and has high catalytic activity, the propane conversion rate is high, the propylene selectivity is good, the one-path stability is good, in addition, the service life is longer, the preparation method of the catalyst carriers is simple and feasible, the economic benefit is obvious, and good industrial development and application prospects are realized.

Heat-curable silicone compositions employing a reactive silicone, a silicone hydride crosslinker and a catalyst system which includes a rhodium-based catalyst, a stabilizing system are disclosed. A combination of rhodium and platinum-based catalysts are employed as well. The compositions are low temperature curing and are capable of providing low coefficient of thermal expansion compositions. A stabilizer system which includes in combination a peroxide and an acetylenic compound is also disclosed.

An emission control catalyst that exhibits improved CO and HC reduction performance includes a supported platinum-based catalyst, and a supported palladium-gold catalyst. The two catalysts are coated onto different layers, zones, or monoliths of the substrate for the emission control catalyst such that the platinum-based catalyst encounters the exhaust stream before the palladium-gold catalyst. Zeolite may be added to the emission control catalyst as a hydrocarbon absorbing component to boost the oxidation activity of the palladium-gold catalyst.

An emission control catalyst includes copper-ceria to boost low temperature CO oxidation performance, generate exothermic heat during the process, and reduce HC and NOx emissions. As a result, system performance is boosted at equal catalyst cost or maintained at a reduced catalyst cost. In one embodiment, an engine exhaust catalyst includes a first washcoat layer having at least one of a platinum-based catalyst, a palladium-based catalyst, and combinations thereof; and a second washcoat layer having copper-ceria.

The invention discloses a preparation method of a platinum based / nitrogen doped carbon quantum dot-carbon nanotube catalyst. The preparation method comprises the following steps: 1, weighing a certain amount of a carbon source to mix with deionized water, and performing ultrasonic dispersion for 1-3 hours; 2, weighing a certain amount of carbon nanotubes to mix with a solution of the carbon source, thereby obtaining a mixture A; 3, putting the mixture A into a reaction kettle, heating at 140-180 DEG C for 1-12 hours, cooling, washing with deionized water, filtering, and performing vacuum drying to obtain a material B; and 4, preparing a platinum based catalyst by virtue of a microwave assisted ethylene glycol reduction method by taking the material B as a carrier, thereby obtaining the platinum based / nitrogen doped carbon quantum dot-carbon nanotube catalyst. According to the preparation method disclosed by the invention, nitrogen doped carbon quantum dots are used for modifying untreated carbon nanotubes and are compounded with the carbon nanotubes, so that the dispersity of platinum ions in the composite carrier is improved, and then the activity of the catalyst is promoted. The preparation method disclosed by the invention is simple and feasible, promotes the activity of the platinum based catalyst to a greater degree, and is hopeful for commercial application.

Provided is a heat conductive silicone grease composition including (A) 100 parts by mass of an organopolysiloxane containing 2 or more alkenyl groups bonded to silicon atoms within each molecule, (B) an organohydrogenpolysiloxane containing 2 or more hydrogen atoms bonded to silicon atoms within each molecule, in sufficient quantity to provide from 0.1 to 5.0 hydrogen atoms bonded to silicon atoms within the component (B) for each alkenyl group within the component (A), (C) 100 to 2,200 parts by mass of a heat conductive filler, (D) an effective quantity of a platinum-based catalyst, and (E) an effective quantity of an addition reaction retarder, in which the component (C) includes more than 90% by mass and no more than 100% by mass of an indium powder with an average particle size of 0.1 to 100 μm. Also provided is a heat conductive silicone cured product obtained by curing the above composition by heating at a temperature equal to, or greater than, the melting point of the indium powder. Further provided is an electronic device including an electronic component, a heat radiating member, and a heat conductive member including the above cured product disposed between the electronic component and the heat radiating member. Still further provided is a method of curing the above composition. Even further provided is a method of forming a heat conductive member between an electronic component and a heat radiating member. The above heat conductive silicone grease composition generates a suitably thin cured product with excellent thermal conductivity that prevents problems such as the contamination of components other than the coated component, and the leakage of oily materials from the product if used over extended periods.

The invention relates to an iron and nitrogen doped carbon black catalyst and a preparation method of the iron and nitrogen doped carbon black catalyst, and solves the technical problems that the preparation method of an oxygen reduction catalyst with carbon as the carrier is complex, and requirements for devices are high. The catalyst of the invention is prepared in the following processes: carbon blacks are mixed with melamine evenly through ball milling technique; and the mixed material is doped with iron atoms due to the use of ball milling technique, the iron atoms and nitrogen atoms are enabled to be doped into a stratified structure of the carbon blacks after a high-temperature treatment, and the iron and nitrogen doped carbon black catalyst is formed. The catalyst is very high in oxygen reduction activity, much higher than platinum base catalysts in oxygen reduction initial potential and half wave potential, and higher than the prior oxygen reduction catalyst with the carbon as the carrier in oxygen reduction activity. The preparation method of the iron and nitrogen doped carbon black catalyst is simple, practical, and low in cost. Therefore, the oxygen reduction catalyst is suitable for being used to prepare fuel cells.

The invention relates to a low-hardness glue-dispensing shaping shielding conductive adhesive as well as a preparation method and application thereof. The conductive adhesive comprises the following components in parts by weight: (A) 100 parts of organic polysiloxane of which each molecule comprises at least two alkenyl; (B) 2-10 parts of the organic polysiloxane of which each molecule comprises at least two silicon-hydrogen bonds and a hydrolysable group; (C) 100-350 parts of metal base conductive fillers; (D) 0.001-0.005 parts of Pt-based catalyst; and (E) 0.1-2.0 parts of aluminum compounds or zirconium compounds or titanium compounds. Compared with the prior art, the conductive adhesive provided by the invention has the advantages of low hardness, high conductivity, high shielding performance, strong shaping ability, excellent adhesiveness and the like.

An electrically conductive silicone rubber composition comprises, at least, (A) 100 parts by weight of an organopolysiloxane having at least two alkenyl groups per molecule, (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule (an amount sufficient to cure the present composition), (C) a platinum based catalyst (an amount sufficient to promote the cure of the present composition), (D) 50 parts by weight to 5,000 parts by weight of a metal based electrically conductive filler, and (E) 5 parts by weight to 500 parts by weight of spherical silicone rubber particles with a surface active agent content of not more than 0.3 wt %.

Provided is a heat conductive silicone grease composition, including: an organopolysiloxane containing 2 or more alkenyl groups bonded to silicon atoms within each molecule, an organopolysiloxane with a specific structure and with a kinematic viscosity at 25° C. of 10 to 10,000 mm2 / s, an alkoxysilane containing specific substituent groups, an organohydrogenpolysiloxane containing 2 or more SiH groups within each molecule, a heat conductive filler, a platinum-based catalyst, and an addition reaction retarder. The heat conductive silicone grease composition exhibits high thermal conductivity, has excellent fluidity prior to curing and therefore exhibits favorable workability, is capable of filling fine indentations and therefore reduces contact resistance, and is also able to prevent oil separation and bleeding of the heat conductive material following curing, meaning the composition exhibits excellent heat radiation performance and reliability. Also, the heat conductive silicone grease composition exhibits improved durability under conditions of high temperature and high humidity, and thereby exhibits further improved reliability during actual use.

An adhesive for silicone rubber, comprising at least the following: A 100 parts by weight of an organopolysiloxane having an average of two or more alkenyl groups per molecule; B an organopolysiloxane having an average of two or more silicon bonded hydrogen atoms in each molecule, used in an amount such that the molar ratio of silicon bonded hydrogen atoms in component B to alkenyl groups in component A at which the molar ratio of the silicon bonded hydrogen atoms in this component to the alkenyl groups in component A is from 0.01 to 20 (i.e. from 1:100 to 20:1); C from 5 to 200 parts by weight of calcium carbonate powder with a BET specific surface area of from 5 to 50 m.sup.2g; and D a platinum-based catalyst, used in an amount capable of inducing curing in the present composition.

A silicone elastomer having hydrophilic properties is provided. The elastomer is a copolymer that is formed from a crosslinkable silicone composition, the silicone composition comprising an organopolysiloxane component and an ethylenically unsaturated monomer component. For example, the silicone composition may comprise: i) an organopolysiloxane having the following general formula: wherein, each R2 is individually selected from unsubstituted and substituted monovalent hydrocarbon groups containing from 1 to 20 carbon atoms; each R3 is individually selected from unsubstituted and substituted alkenyl groups containing from 1 to 20 carbon atoms; x≧1; and y≧0 and is an integer that is selected so that the organopolysiloxane contains an average of at least two alkenyl groups per molecule; ii) an ethylenically unsaturated carboxylic acid; iii) a silicon hydride crosslinking agent; and iv) a platinum-based catalyst.

The invention discloses a noble metal catalyst for preparing propylene through propane dehydrogenation and a preparation method thereof, and is used for mainly solving the problems that a noble metal catalyst is prone to carbon deposition and deactivation at high temperature to affect the stability of the catalyst. The used catalyst can be represented by PtSnCa / Al2O3, that is to say, platinum and tin components are supported on an alumina carrier, and a second auxiliary agent calcium oxide is introduced, so as to improve the stability of the catalyst. The catalyst is adopted for catalysis of propane dehydrogenation to prepare propylene under conditions of the temperature of 590 DEG C and the pressure of less than 0.2 MPa, the life of the catalyst can reach 145 h, and the service life of the catalyst is greatly prolonged, so that the problem is relatively well solved. The catalyst is in favor of industrialized promotion of propane dehydrogenation for preparing propylene.

The invention relates to a liquid filling and sealing composition for bi-component additive silicon rubber and a preparation method thereof. The composition comprises the following components from (A) to (F): (A) 100 mass portions of univalent unsaturated fatty hydrocarbon polysiloxane, wherein at least 2 or more than 2 bonds in each molecule are connected to a silicon atom; (B) 0.1 to 50 mass portions of hydrogen atomic hydrogenated polysiloxane, wherein at least 2 or more than 2 bonds in each molecule are connected to a silicon atom; (C) 10 to 70 mass portions of electronic grade quartz powder; (D) platinum based catalyst; (E) a triazole compound; and (F) 0.001 to 0.009 mass portion of acetylenyl cyclohexanol. The preparation method is as follows: the (A) component, the (B) component and the (C) component are mixed and milled by a kneader to prepare a basic composition; and the (D) component, the (E) component and the (F) component are added into the basic composition, and the mixture is subjected to vacuum defoamation and high-temperature solidification to obtain the silicon rubber. The liquid filling and sealing composition for the bi-component additive silicon rubber is convenient to use, is safe and reliable, does not pollute the environment, has stable service performance, can not be cracked at a low temperature, and has the characteristics of moisture protection, dust prevention, corrosion resistance, shock resistance and so on.

A platinum-based nano catalyst supported carbon nano tube electrode and a manufacturing method thereof, more particularly to a manufacturing method of a carbon nano tube electrode and a carbon nano tube electrode supported with the platinum-based catalyst by growing the carbon nano tube on the surface of the carbon paper and using a CVD method on the surface of the carbon nano tube. By growing the carbon nano tube directly, the broad surface area and excellent electric conductivity of the carbon nano tube can be utilized maximally, and especially, the nano catalyst particles with minute sizes on the surface of the carbon nano tube by using the CVD method as a supporting method of the platinum-based catalyst on the surface of the carbon nano tube, the amount of the platinum can be minimized and still shows an efficient catalyst effect and by improving the catalyst activity by increasing the distribution, so academic and industrial application in the future is highly expected.

A curable organopolysiloxane composition is provided, which includes (A) an organopolysiloxane containing at least one silicon atom-bonded alkenyl group within each molecule, (B) an organohydrogenpolysiloxane, which contains, within each molecule, at least one silicon atom-bonded hydrogen atom at a molecular chain terminal, and at least two silicon atom-bonded hydrogen atoms at non-terminal positions within the molecular chain, and which satisfies the formula shown below: 0<α / β0.25(wherein, a represents the number of silicon atom-bonded hydrogen atoms at non-terminal positions within the molecular chain, and β represents the total number of silicon atoms within the component (B)), in sufficient quantity to provide from 0.1 to 5 silicon atom-bonded hydrogen atoms per silicon atom-bonded alkenyl group within the component (A), and (C) a platinum-based catalyst. The composition can be cured even at low temperatures, generates a cured product that suffers no surface wrinkling, and displays excellent storage characteristics

The invention discloses a platinum-based catalyst carrier of a proton exchange membrane cell (PEMFC) and a preparation method of the platinum-based catalyst carrier. The platinum-based catalyst carrier is a g-C3N4 nanosheet / quasi-graphene carbon composite material. The preparation method comprises steps as follows: (1), a g-C3N4 precursor and inorganic salt are weighed and mixed uniformly to obtain a mixture A; (2), the mixture A is put into nitrogen atmosphere of a tube furnace in a semi-sealed manner, is heated to 500-700 DEG C and remains at the temperature for 1-5 h to obtain a material B; (3), the material B is ground, then washed and filtered with super-pure water and subjected to vacuum drying to obtain a block-shaped g-C3N4 material C; (4), the g-C3N4 material is added to concentrated acid, subjected to ultrasonic-wave stirring, washed with super-pure water until the pH is neutral, and subjected to centrifugal drying to obtain a g-C3N4 nanosheet; (5), the g-C3N4 nanosheet and quasi-graphene carbon are weighed, added to an alcohol solution and subjected to ultrasonic dispersion, extraction filtration and freezing drying to obtain a composite material. The preparation method is simple and feasible, the precious metal carrying capacity of the platinum-based catalyst is promisingly reduced, and accordingly, the production cost of the fuel cell is reduced.

The invention relates to a catalyst used for preparing 1,3-propylene glycol through glycerin hydrogenolysis, and specifically relates to a preparation method and an application of a mesoporous-tungsten oxide-supported platinum-based catalyst. According to the invention, mesoporous tungsten oxide is adopted as a carrier, and active components such as metal platinum or other noble metals are highly dispersed on the surface of the carrier, wherein the theoretical content of the active components accounts for 0.1-40% of the mass of the carrier. The catalyst is characterized by good selectivity and high activity. With the catalyst, high-selectivity preparation of 1,3-propylene glycol can be realized through glycerin hydrogenolysis under hydrothermal conditions comprising a temperature of 120-300 DEG C and a hydrogen pressure of 0.1-15MPa.

The invention discloses a catalyst for catalyzing and oxidizing oxynitride in flue gas, which is prepared by using mesoporous silica as a vector, one or mixture of two of kalium and molybdenum as a doping component and platinum as an active component by adopting an equal-volume stepwise impregnation method. The invention also discloses a process for preparing the catalyst, and simultaneously discloses application of the catalyst in flue gas denitration process. Under the action of the catalyst, by utilizing oxygen contained in the flue gas per se, nitrogen oxide is oxidized into nitrogen dioxide which is easily dissolved in water, so that the oxidizability of nitric oxide in the flue gas can be improved, and the flue gas is absorbed and denitrated by utilizing alkali liquor. The kalium and polybdenum doped platinum-based catalyst prepared by the process has catalytic oxidation performance obviously superior to an undoped platinum-based catalyst, and has high denitration efficiency; and under the catalytic oxidation action of the kalium and polybdenum doped platinum-based catalyst, the NOx oxidizability in the oxidized flue gas is just between 45 and 65 percent, and the denitration side product nitrite can be reclaimed so as to realize recycling of the denitration product.

The invention discloses a quaternary platinum-based catalyst used for production of propylene through propane dehydrogenation, and a preparation method and an application thereof. The catalyst treats alumina processed by an alkaline gas as a carrier, precious metal Pt and metal Sn as active components, and M1 and M2 as assistants, M1 is one selected from Na, K, Rb, Mg, Ca and Sr, and M2 is one selected from La, Ce, Pm, Sm, Ti, Ga, In, Zn and Fe. The finally obtained catalyst comprises 0.2-0.3wt% of Pt, 0.1-2wt% of Sn, 0.5-2wt% of M1 and 0.5-2wt% of M2. The preparation method of the catalyst comprises the following steps: preprocessing the alumina carrier by the alkaline gas, and loading Pt, Sn, M1 and M2 through an impregnation process. The catalyst prepared through the method has the advantages of low price, simple operation, high reaction activity, good propylene selectivity, long single-use life and the like when the catalyst is used to catalyze a production reaction of propylene through propane dehydrogenation.

The invention relates to LED packaging silicone rubber, particularly relates to the high-refractive-index LED packaging silicone rubber, and belongs to the adhesive technical field. The high-refractive-index LED packaging silicone rubber includes a component A and a component B, and the weight ratio of the component A to the component B is 10 to 1. The component A includes the following raw material components in parts by weight: 80-90 parts of methyl phenyl vinyl silicon resin, 8-18 parts of vinyl dimethyl diphenyl polysiloxane, 0.1-0.3 part of a platinum-based catalyst, and 1-5 parts of an adhesive. The component B includes the following raw material components in parts by weight: 40-60 parts of methyl phenyl hydrogen-containing silicon resin, 40-60 parts of hydrogen-terminated diphenyl polysiloxane, and 0.1-0.3 part of an inhibitor. The high-refractive-index LED packaging silicone rubber has the beneficial effects of high hardness, vulcanization resistance, excellent adhesion, excellent hot and cold shock resistant performance and the like.

Heat-curable silicone compositions employing a reactive silicone, a silicone hydride crosslinker and a catalyst system which includes a rhodium-based catalyst, a stabilizing system are disclosed. A combination of rhodium and platinum-based catalysts are employed as well. The compositions are low temperature curing and are capable of providing low coefficient of thermal expansion compositions. A stabilizer system which includes in combination a peroxide and an acetylenic compound is also disclosed.

The invention discloses a method for preparing a carbon-supported platinum-based catalyst of a fuel cell by a solvothermal method, which is applied to a proton exchange membrane fuel cell and comprises the steps of: In the cathode reaction of oxygen fuel cell and direct alcohol fuel cell, it belongs to the electrochemical catalytic reaction field. A solvothermal reduction process is used, A support carbon material is sufficiently dispersed in a solvent, A metal precursor solution is added with stirring, that mass percentage of the active ingredient reaches 20 to 60 wt% in the prepared catalyst, the pH value of the solution is adjusted to above 9 by an alkaline solution, and the mixture is react in a high-temperature and high-pressure sealed reaction vessel. After the reaction, the pH valuewas adjusted to less than 5 by acidic solution, and the reaction solution was filtered, washed, dried and ground to obtain carbon-supported platinum-based electrocatalyst. The catalyst active ingredient prepared by the invention has small particle diameter and is uniformly dispersed on a carbon carrier, and has high activity. The preparation process of the invention is simple in operation, rapidin reaction, low in energy consumption, low in cost, and easy to realize mass industrial production.

Provided is a curable organopolysiloxane composition which includes (A) an organopolysiloxane containing at least 2 alkenyl groups bonded to silicon atoms within each molecule, (B) an organohydrogenpolysiloxane containing at least 2 hydrogen atoms bonded to silicon atoms within each molecule, (C) gallium and / or an alloy thereof, with a melting point within a range from 0 to 70° C., optionally (D) a heat conductive filler with an average particle size within a range from 0.1 to 100 μm, (E) a platinum based catalyst, and (F) an addition reaction control agent. The composition is useful as a material capable of forming a layer with excellent thermal conductivity that is sandwiched between a heat generating electronic component and a heat radiating member.

The present invention provides a fuel cell alloy catalyst preparation method, which specifically comprises: adopting a platinum-based catalyst as a substrate, depositing a transition metal hydroxide on the surface, carrying out a heat treatment in a reducing atmosphere to obtain a platinum-based-transition metal / charcoal alloy catalyst, and carrying out acid washing on the obtained alloy catalyst in an acidic solution to remove the transition metal on the surface so as to obtain the product. According to the present invention, the alloy catalyst obtained by using the preparation method provides high unit mass Pt catalysis activity for the oxygen reduction, and the stability is substantially improved relative to the substrate platinum-based catalyst; and the method is suitable for large-scale production.

The invention relates to a preparation method of hollow carbon nanocage loaded platinum-based composite catalysts, which includes the following steps of dispersing hollow carbon nanocages into solution containing platinum ions and reducing by the aid of a reducing agent so as to obtain the hollow carbon nanocage loaded platinum-based composite catalysts. The mass ratio of the platinum-based nano particles to the hollow carbon nanocages is 0.005-1, namely the metal particles accounts for 0.5-50% of the total mass of the catalyst. The mole ratio of platinum ions to other metal ions is a:b, wherein the a is equal to 0-1 but not equal to 0, and the b is equal to 0-1. The M is one of Ru, Fe, Co, Ni or Cu or a mixture of two or more of Ru, Fe, Ni or Cu according to any proportion. The hollow carbon nanocage loaded platinum-based composite catalysts prepared by the method and in the size ranging from 1nm to 15nm are good in dispersion degree and small in range of particle size distribution, can be used for proton exchange membrane fuel cells and direct-methanol fuel cells, can also be applicable to chemical reaction catalyzed by other platinum-based catalysts, and have excellent catalytic activity and stability.

The invention provides a dynamic vulcanized silicone rubber / thermoplastic polyurethane elastomer material and a preparation method thereof. The material is prepared, by weight, the following components: vinyl polysiloxane: 100 parts, thermoplastic polyurethane elastomer: 10-500 parts, compatibilizer: 3-30 parts, hydrogen-containing silicone oil: 0.1-15 parts, platinum-based catalyst: 0.1-100 ppm (content of platinum atom in the vinyl polysiloxane and hydrogen-containing silicone oil), anti-poison agent: 0.1-20 parts. In the preparation process, no hydrogen is generated, and the process is simple and safe. The product integrates the advantages of two materials of silicon rubber and TPU, has excellent surface hand feeling, has excellent adhesion with PC, PC / ABS, ABS and the like, is easy toextrude and formed through injection molding, the additive amount of the platinum-based catalyst is low in the preparation process, the product has excellent endurance performance and low cost, and can be widely applied to the fields of intelligent wearable products and electronic and appliance products and the like with relatively high requirements.