852 results about "Alloy catalyst" patented technology

A platinum/ruthenium alloy catalyst that includes finely dispersed alloy particles on a powdery, electrically conductive carrier material. The catalyst is particularly resistant to carbon monoxide poisoning when the alloy particles display mean crystallite sizes of 0.5 to less than 2 nm.

Particulate skeletal iron catalyst is provided which contain at least about 50 wt. % iron with the remainder being a minor portion of a suitable non-ferrous metal and having characteristics of 0.062-1.0 mm particle size, 20-100 m2/g surface area, and 10-40 nm average pore diameter. Such skeletal iron catalysts are prepared and utilized for producing synthetic hydrocarbon products from CO and H2 feeds by Fischer-Tropsch synthesis process. Iron powder is mixed with non-ferrous powder selected from aluminum, antimony, silicon, tin or zinc powder to provide 20-80 wt. % iron content and melted together to form an iron alloy, then cooled to room temperature and pulverized to provide 0.1-10 mm iron alloy catalyst precursor particles. The iron alloy pulverized particles are treated with NaOH or KOH caustic solution at 30-95° C. temperature to extract and/or leach out most of the non-ferrous metal portion, and then screened and treated by drying and reducing with hydrogen and to provide the smaller size skeletal iron catalyst material. Such skeletal iron catalyst is utilized with CO+H2 feedstream for Fischer-Tropsch reactions in either a fixed bed or slurry bed type reactor at 180-350° C. temperature, 0.5-3.0 mPa pressure and gas hourly space velocity of 0.5-3.0 L/g Fe/hr to produce desired hydrocarbon products.

Methods of forming polycrystalline diamond elements include forming a polycrystalline diamond element. A Group VIII metal or alloy catalyst is employed to form the polycrystalline diamond compact table at a pressure of at least about 6.5 GPa or greater. The catalyst is then removed from at least a portion of the table to a depth from a working surface thereof, and may be removed from the entirety of the table. Polycrystalline diamond elements include such polycrystalline diamond compact tables. Earth-boring tools include such polycrystalline diamond elements carried thereon and employed as cutting elements.

The invention discloses a method for preparing a graphene film by using a liquid metal or alloy as a catalyst and adopting chemical vapor deposition. The metal with low melting point comprises typical gallium, tin, indium and the like; and the alloy with low melting point comprises gallium-copper, gallium-nickel, indium-copper, indium-nickel, tin-copper, tin-nickel, copper-silver-tin and the like. The chemical vapor deposition is performed above the melting point of the metal or alloy catalyst, so that the continuous graphene film is formed on the surface of the catalyst and the interface of the catalyst and a substrate. Compared with the graphene grown on the surface of a solid catalyst such as copper and nickel, the invention has the advantages that the prepared graphene is controllable in layer number, low in requirement for the micro morphology of the surface of the substrate and suitable for multiple substrate materials, and the catalyst is very easy to remove. The obtained graphene positioned on the surface of the liquid has unique application value.

The present invention relates to a palladium-containing alloy single atom catalyst for selective hydrogenation of alkyne. According to the catalyst, an inert oxide SiO2 is adopted as a carrier, Pd and one or two or more than two materials selected from metal elements in group IB or Group VIII excluding Pd are combined to prepare the supported palladium-containing alloy catalyst so as to make the Pd be in the complete or partial single atom distribution state, wherein the Pd accounts for 0.002-1% of the weight of the carrier, and the content of other metal elements accounts for 0.2-8% of the weight of the carrier. The palladium-containing alloy single atom catalyst has characteristics of high catalytic hydrogenation activity, high ethylene selectivity and the like, and has the good reaction catalysis performance in the reaction for preparing ethylene gas to eliminate trace acetylene through petroleum cracking under the condition close to the industrial condition.

An alkylbenzene is alkylated with an alkene, in the presence of a sodium/potassium alloy catalyst, on a saturated carbon atom which is alpha to the ring at temperatures which are lower than the temperatures used in a current commercial process. In a pre-alkylation reaction, the catalyst is reacted with a compound which has a saturated carbon atom alpha to a double bond in order to form a catalytic species. Higher amounts of catalyst are used in the pre-alkylation reaction than in the analogous reaction of the current commercial process. Following alkylation, the phase which contains the alkylation product is separated from the phase which contains the catalytic species. The process produces less isomeric and other soluble byproducts, and enables the efficacious production of longer chain alkylbenzenes without the formation of insoluble tars characteristic of the current commercial process.

The invention provides a self-supporting transition metal-phosphorus alloy catalyst, and a preparation method and an application thereof, and belongs to the field of alkaline electrolytic bath water decomposition. The preparation method of the catalyst comprises the following steps: mixing the salt of a transition metal element with a phosphorus source, and adding a surfactant or an alkaline solution to obtain an electrolyte; and electrodepositing in the electrolyte with a transition metal conductive substrate as a working electrode in order to obtain the self-supporting transition metal-phosphorus alloy catalyst. The invention also provides the self-supporting transition metal-phosphorus alloy catalyst prepared through the preparation method. The self-supporting transition metal-phosphorus alloy catalyst has excellent electrocatalytic hydrogen evolution and oxygen evolution performances in electrolytic baths.

The present invention discloses a loaded type amorphous alloy catalyst for preparing cyclohexanone by means of phenol catalytic hydrogenation and its preparation method. Said invention utilizes isochoric impregnation KBH4 reduction method to prepare amorphous alloy catalyst, said preparation method includes the following steps: preparing hydrotalcite carrier; making metal salt precursor solution and hydrotalcite carrier undergo the process of isochoric impregnation treatment; drying; roasting; drop-adding reductant KBH4 solution to make reduction; successively using deionized water and absolute ethyl alcohol to wash black solid precipitate obtained by above-mentioned solution reaction to neutrality so as to obtain the invented amorphous alloy catalyst.

The present invention provides a method for manufacture of supported noble metal based alloy catalysts with a high degree of alloying and a small crystallite size. The method is based on the use of polyol solvents as reaction medium and comprises of a two-step reduction process in the presence of a support material. In the first step, the first metal (M1=transition metal; e.g. Co, Cr, Ru) is activated by increasing the reaction temperature to 80 to 160° C. In the second step, the second metal (M2=noble metal; e.g. Pt, Pd, Au and mixtures thereof) is added and the slurry is heated to the boiling point of the polyol solvent in a range of 160 to 300° C. Due to this two-step method, an uniform reduction occurs, resulting in noble metal based catalysts with a high degree of alloying and a small crystallite size of less than 3 nm. Due to the high degree of alloying, the lattice constants are lowered. The catalysts manufactured according to the method are used as electrocatalysts for polymer electrolyte membrane fuel cells (PEMFC), direct-methanol fuel cells (DMFC) or as gas phase catalysts for CO oxidation or exhaust gas purification.

A carried non-crystal Pd alloy catalyst for hydrogenating anthraquinone to prepare H2O2 is prepared from the carrier which is one or two of gamma-Al2O3, alpha-Al2O3, MgO, activated carbon, molecular sieve and mullite, non-crystal PdB alloy and RE element through immersing the carrier in the solution of RE metal's nitrate under ultrasonic condition, calcining at 400-700 deg.C for 2-5 hr, immersing in PdCl2 solution, dropping KBH4 solution in ice water bath, and washing. Its advantages are high catalytic activity and low cost.

The invention discloses a catalytic oxidation catalyst for methyl acetate in organic waste gas and a preparation method thereof. The catalyst is a supported noble metal alloy catalyst, wherein the noble metal alloy is an arbitrary metal combination of two or more of Pd, Pt, Rh, Au and Ag; the vector is activated alumina and/or titanium dioxide, as well as at least one transition metal oxide whichcomprises metal oxide of manganese, cerium, nickel, lanthanum, copper, vanadium, tungsten, iron, cobalt or chrome; and the weight ratio of the noble metal alloy to the vector is (1:2,000)-(1:5). The catalyst provided by the invention can be used for treating organic waste gas containing methyl acetate, especially for treating waste gas of a PTA (purified terephthalic acid) device, by a catalytic oxidation method; and the catalyst has the advantages of simple preparation, high catalytic oxidation activity, good stability, excellent halogenated hydrocarbon poisoning resistance and high practical application value.

The invention belongs to the technical field of electrochemical energy, in particular to a low-platinum carbon-supported nanometer Pd-Pt alloy catalyst, and a preparation method and an application thereof. The invention provides the low-platinum carbon-supported nanometer Pd-Pt alloy catalyst; wherein, the Pd-Pt alloy catalyst particles are supported by carbon carrier, the content of Pd-Pt alloy in the carbon-supported nanometer Pd-Pt alloy catalyst is 1-60wt%, the molar ratio of Pd to Pt is 10:0.01-5 and the central particle size of the Pd-Pt alloy catalyst particles is 1.5-50nm. Compared with the traditional Pd/C and Pt/C catalyst, the low-platinum carbon-supported nanometer Pd-Pt alloy catalyst provided by the invention has better catalytic performance to the oxidation of formic acid and longer catalytic stability.

The invention involves a load palladium amorphous alloy catalyst used for nitrophenol hydrogenation and preparation method and belongs to catalyst technology field. Said catalyst uses NaY, MCM-41, molecular screen, Al2O3, TiO2, SiO2 or MgO as carrier, and is loaded with Pd-B amorphous alloy, the quality of Pd is 0.1-0.5% of toatl quality of catalyst. The preparation process includes ultrasonic dispersion, vacuum impregnation, KBH4 chemical reduction under vacuum conditions, filtration and washing of carriers; it is characterized by introducing vacuum and ultrasonic radiation conditions. The advantages of the invention lies in its high activity of catalyst, low preparation cost and simple preparation process, it could widely apply to the preparation of p-aminophenol through nitrophenol catalysis and hydrogenation.

A process for preparing 1,3-propanediol from formaldehyde and acetaldehyde includes such steps as under existance of alkali and organic solvent, reacting at 10-40 deg.C for 2-10 hr to obtain 3-hydroxypropanol, making the 3-hydroxypropanal in contact with catalyst, and hydrogenation reaction at 50-100 deg.c and 3-9 MPa. The said catalyst contains Ni (70-90 wt.%), Fe or Mo (0-9), P (1-5) and Al (rest). Its advantages are high output rate, high safety, and high activity and selectivity of said catalyst.

Embodiment of the present invention relate to dendrimers useful for application as catalysts, in particular as improved electrocatalysts for polymer electrolyte membrane fuel cells (PEM-FCs). Methods of preparing such catalysts are described. Examples include dendritic nanostructured metal catalysts, such as platinum and platinum-alloy catalysts.

The invention relates to a porous material supported nano alloy catalyst as well as a preparation method and application thereof and belongs to the technical field of nano material application and catalysis. The preparation method for the porous material supported nano alloy catalyst is characterized comprising the step of reaction through taking a metallic compound as a precursor, a porous material as a carrier and a borane substance as a reducing agent under the action of supercritical carbon dioxide used as a fluid medium; in the catalyst, the types of nano alloy are selected from Pt, Au, Ag, Pd, Ru, Rh, Pb, Fe, Co, Ni, Ir, Cu and the like and can be arbitrarily matched and proportioned; the size of each of nano alloy particles is about 1-2 nm. The nano particles not only can be distributed on the surface of the carrier, but also can be distributed in holes, even mesopores; therefore, the catalyst has higher catalytic activity and stability.

Techniques herein prepare an alloy catalyst using a protective conductive polymer coating. More particularly, an alloy catalyst is prepared by: preparing a platinum catalyst supported on carbon; coating the surface of the platinum catalyst with a conductive polymer; supporting a transition metal salt on the coated catalyst; and heat treating the catalyst on which the transition metal salt is supported. Also, an alloy catalyst may be prepared by: preparing a platinum-transition metal catalyst supported on carbon; coating the surface of the platinum-transition metal catalyst with a conductive polymer; and heat treating the coated catalyst. Accordingly an alloy catalyst with superior dispersity can be prepared by increasing the degree of alloying of the catalyst through heat treatment while preventing the increase of catalyst particle size through carbonization of the conductive polymer. The prepared catalyst may be useful, for example, for a fuel cell electrode.

Disclosed is a preparation method for modified noncrystalline nickel alloy catalyst, comprising processes of heating up the metallic nickel and the metallic aluminium into a melting state, preparing the nickel aluminium alloy by rapid quenching, and extraction and dealuminizing; the utility model is characterized in that the alloy got from the extraction and dealuminizing is washed to a PH value of 7 to 13 by the deionized water; and then the alloy is contacted with the salt solution of one or a plurality of metal promoters selected from the rare earth metal or the IIB,VIB,VIIB,VIII group metal; and calculated based on the weight of the metal nickel, the weight of the promoter metal used in the contact is less than 10 percent by weight. The metallic modified noncrystalline alloy prepared by the method has the advantages of high retention rate of the metal promoters, high hydrogenation activity and stability.

The present invention belongs to the field of chemical technology and is especially one catalyst for anthraquinone hydrogenation process of preparing hydrogen peroxide and its preparation. The catalyst is obtained with some alloy and through active treatment with alkali solution and the alloy consists of Ni, Al and metal additive including one or several of Cr, Mo, W, Fe, Co, Cu and Zn. The catalyst is one kind of amorphous skeleton alloy catalyst prepared through high temperature melting of metal components, quenching stress to obtain alloy strip or scaly alloy, grinding, sieving and activation in alkali solution. Compared with traditional Raney Ni catalyst, the said catalyst has high anthraquinone hydrogenation activity and high selectivity.

The invention discloses amorphous alloy catalyst with controllable grain size being smaller than 50 nm and uniform grain size distribution, and adds a new variety for the prior amorphous alloy catalyst field. The activity ratio surface area of the amorphous alloy catalyst is 10 to 50 m<2>/g, the particle diameter can be controlled in the range of 2 to 50 nm, and the grain size distribution is uniform. The invention realizes the amorphous alloy catalyst with the grain size being smaller than 50 nm and achieves the controllable grain size and the uniform grain size distribution through the preparation method for controlling the reduction reaction rate by oil in water microemulsion. The amorphous alloy catalyst of the invention can be taken as hydrogenation catalyst containing unsaturated functional group compounds such as alkene, alkyne, arene, nitrile, nitro compound, carbonyl compound, etc., not only the catalytic performance is superior to the catalytic performance of the ordinary amorphous alloy catalyst, but also the catalytic performance can be controlled; the life of the catalyst is longer than the life of the ordinary amorphous alloy catalyst, and the catalyst can be recovered and reused time after time.

A microwave aided process for preparing the catalyst of non-crystalline NiB alloy suitable for catalytic hydro-reaction with high catalytic active features that the chemical reduction and chemical plating in microwave field is used, KBH4 is used as reducer, its primary salt is chosen from nickel sulfate, nickel acetate, etc, its secondary salt is chosen from cobalt chloride, iron chloride, etc, its carrier is chosen from oxide, molecular sieve, etc, its solvent is chosen from water, tetrahydrofuran, etc and the complex agent, stabilizer and additive is used.

The invention discloses a preparation method of a nitrogen-doped nano catalyst adopting a double-shell-layer structure. The method comprises the following operation steps: (1) a carrier and a metal precursor are added to a solvent and stirred, a reducing agent is added for reduction, filtration, cleaning and drying are performed, and a primary product is obtained; (2) the primary product is placed in a high-temperature reaction furnace, gas is introduced for calcination, and a nitrogen-doped nano alloy catalyst is obtained; (3) dealloying treatment is performed and the nitrogen-doped nano catalyst adopting the double-shell-layer structure is obtained. The oxygen reduction quality activity of the catalyst at 0.9 V is 5-19 times that of a commercial 20wt% Pt/C catalyst, the catalyst prepared with the method has higher oxygen reduction catalytic performance, and a technological foundation is laid for mass application of proton exchange membrane fuel cells.

The feature of the process for ultra-low alloy catalyst loading electrode according this invention is to reduce its alloy formation period of aging process subsequent to hydrogen reduction process of catalyst ions after ion exchange process of their ions and proton in the cluster of the polymer electrolyte on the surface of the carbon powder. The process is able to drastically shorten the aging time with temperature rise beyond 200° C. up to 400° C. under hydrogen atmosphere for the formation of Pt—Ru binary alloy for example catalyst by the additional processes of pre-treatment of K⁺, Na⁺, Li⁺, Rb⁺, Cs⁺, Mg²⁺, Ca²⁺, Ba²⁺, Fe²⁺, Sr²⁺, Ra²⁺, Cu²⁺, Ag⁺, Zn²⁺, Ni²⁺, and Co²⁺ ions substitution for proton before the hydrogen reduction process. More preference, the further post-treatment of K⁺, Na⁺, Li⁺, Rb⁺, Cs⁺, Mg²⁺, Ca²⁺, Ba²⁺, Fe²⁺, Sr²⁺, Ra²⁺, Cu²⁺, Ag⁺, Zn²⁺, Ni²⁺, and Co²⁺ ions substitution for proton before the ion exchange process. This new process is little harmful to the CO tolerance performance of PEFC.