2270 results about "Palladium catalyst" patented technology

A carbon-insertion-type palladium metal in which an amount of inserted carbon is 0.16 mol or more with respect to 1.0 mol of a palladium metal, and a carbon-insertion-type palladium metal in which a crystal face distance of a (111) face of a palladium metal is 2.270 Å or more are useful as raw materials of a palladium catalyst for use in an α,β-unsaturated carboxylic acid preparation reaction, and the like. The carbon-insertion-type palladium metal can preferably be prepared by reduction of palladium in a palladium compound having a chlorine content of 0 to 300 ppm.

The invention relates to a synthesis method of D,L-danshensu isopropyl ester. The method comprises taking protocatechuic aldehyde as an initial raw material, protecting phenolic hydroxyl by benzyl, carrying out Darzens epoxidation, followed by carrying out catalytic reduction with palladium catalyst/hydrogen or Raney nickel/hydrogen, and thus obtaining the D,L-danshensu isopropyl ester. The purity of the product synthesized by the method can reach 98%, and the yield can reach 55%. Moreover, the synthesis method has the advantages of simple and easily obtained raw materials, short routes and high yield, and is suitable for large-scale industrialized production.

An engine exhaust catalyst exhibits improved CO oxidation performance relative to conventional engine exhaust catalysts and includes a first supported catalyst comprising platinum and a second supported catalyst comprising palladium and gold species in close contact. The first supported catalyst may be a platinum catalyst, a platinum-palladium catalyst, or a platinum catalyst promoted with bismuth, and the second supported catalyst preferably has a palladium to gold weight ratio of about 0.85:1.0. To improve aged catalyst performance, the first and second supported catalysts are coated onto different layers, zones, or monoliths of the substrate for the engine exhaust catalyst.

The invention relates to a synthesis method of racemic bornyl beta-(3,4-dihydroxyphenyl)-alpha-hydroxypropionate. The method comprises the following steps: carrying out Darzens epoxidation on an initial raw material benzyl protected protocatechualdehyde, and carrying out palladium catalyst/hydrogen or Raney nickel/hydrogen catalytic reduction to obtain racemic bornyl beta-(3,4-dihydroxyphenyl)-alpha-hydroxypropionate. The purity and the yield of a product synthesized by adopting the method reach 98% and 48.6% respectively. The synthesis method has the advantages of simple and easily available raw material, short route, high yield, and suitableness for large scale industrialized production.

An engine exhaust catalyst exhibits improved CO oxidation performance relative to conventional engine exhaust catalysts and includes a first supported catalyst comprising platinum and a second supported catalyst comprising palladium and gold species in close contact. The first supported catalyst may be a platinum catalyst, a platinum-palladium catalyst, or a platinum catalyst promoted with bismuth, and the second supported catalyst preferably has a palladium to gold weight ratio of about 0.85:1.0. To improve aged catalyst performance, the first and second supported catalysts are coated onto different layers, zones, or monoliths of the substrate for the engine exhaust catalyst.

An aromatic dicarboxylic acid is purified by oxidizing m-xylene or p-xylene to produce crude isophthalic acid or crude terephthalic acid, respectively. The products of the oxidizing step are hydrogenated in the presence of a palladium catalyst. Carbon monoxide is introduced during the hydrogenation step. The palladium catalyst is provided on a carbon substrate. The products of the oxidizing step are dissolved in a solvent, which may be water, prior to the hydrogenation step. The products of the oxidizing step may be dissolved at an elevated temperature, above the normal boiling point of the solvent. The oxidation step produces isophthalic acid, 3-carboxybenzaldehyde and fluorenones in the case of oxidizing m-xylene and produces terephthalic acid, 4-carboxybenzaldehyde and fluorenones in the case of oxidizing p-xylene. It may be helpful to monitor the disappearance of 3-carboxybenzaldehyde in the case of oxidizing m-xylene and 4-carboxybenzaldehyde in the case of oxidizing pxylene, and reducing the amount of carbon monoxide when the rate of disappearance is below a predetermined minimum. After the hydrogenation step, the isophthalic acid or terephthalic acid may be crystallized. The carbon monoxide may be maintained at a concentration of 100 to 500 ppm based on added hydrogen and carbon monoxide. Other aromatic dicarboxylic acids may also purified by this procedure.

The invention relates to a method for preparing a carbon supported Au-Pt or Au-Pd catalyst by modifying Au-Pt or Au-Pd bimetal nanoparticles with microwaves, belonging to the technical field of catalytic materials. High pressure and high temperature generated by microwaves in a high-pressure reaction tank are utilized to treat an Au-Pt or Au-Pd composite nano colloid synthesized by a chemical coreduction method so as to induce the modification of the Au-Pt or Au-Pd bimetal nanoparticles; and the microwave-modified bimetal nanoparticles are deposited on the surface of the carbon support, thereby obtaining the carbon supported Au-Pt or Au-Pd catalyst with high activity. The carbon supported Au-Pt or Au-Pd catalyst has high electrocatalytic activity; the supporting rate of the Au-Pt or Au-Pd bimetal is high; the supporting amount of the Au-Pt or Au-Pd is controllable; and the method can be used for preparing the carbon supported Au-Pt or Au-Pd nano catalyst of which the mass ratio of Au-Pt or Au-Pd to carbon is 1-20%. The method provided by the invention has the advantages of low cost, simple technique and low facility request, and has wide industrial application prospects.

The invention relates to a method for producing oxalic ester by CO coupling, which mainly solves the problems of the prior art such as low selectivity and low CO single pass conversion in producing the oxalic ester by CO coupling. In the invention, firstly CO and nitrite ester are put into a coupling reactor and then contacted with a catalyst containing Pd; liquid phase reaction effluent II and gas phase reaction effluent III are obtained from effluent I through gas-liquid separation; the gas phase reaction effluent III, O2 and monohydric alcohol of C1-C4 are taken as raw material and put into a regeneration reactor for reaction to generate gas effluent IV containing nitrite ester; the gas effluent IV returns to the coupling reactor for continuous reaction and the mol ratio of nitrogen oxide:O2:monohydric alcohol of C1-C4 is 1:0.3-0.5:1-1.5. The technical proposal of obtaining the oxalic ester product by separating the liquid phase reaction effluent II better solves the problem and can be applicable to the industrial production of oxalic ester.

The invention discloses a preparation method for a phenanthridine derivative. The preparation method comprises the following steps of: adding a catalyst, an oxidant, acid, a 2-phenylaniline compound and an olefin compound into organic solvent; after reaction, carrying out post treatment to obtain the phenanthridine derivative, wherein the catalyst is a bivalent palladium catalyst. According to the preparation method for the phenanthridine derivative disclosed by the invention, the adoption of reagents with high toxicity and high corrosiveness is avoided. The preparation method has the advantages of environment friendliness, easiness in operation, higher yield and simplicity and convenience in post treatment. In addition, a substrate obtained by the method is strong in designability and can be used for designing to synthesize a compound with the required structure according to actual requirements, and thus stronger practicability is realized.

A container (22) includes a shell (24) made from a polymer, for example PET, and incorporating a catalyst, for example a palladium catalyst. A closure (40) incorporates a plug which includes a source of hydrogen, for example a hydride. In use, with container (22) including a beverage and closure (40) in position, the headspace in the container will be saturated with water vapor. This vapor contacts the hydride associated with plug (42) and as a result the hydride produces molecular hydrogen which migrates into the polymer matrix of shell (24) and combines with oxygen which may have entered the container through its permeable walls. A reaction between the hydrogen and oxygen takes place, catalysed by the catalyst, and water is produced. Thus, oxygen which may ingress the container is scavenged and the contents of the container are protected from oxidation.

The invention relates to a graphene oxide supported Schiff base palladium catalyst as well as a preparation method and application thereof. A catalyst carrier is a graphene oxide prepared by an improved Hummers process, ligand is Schiff base and an active ingredient is palladium salt; the capacity of the palladium in the active ingredient palladium salt is 5.0%-10.0% of the total mass of the catalyst, the diameter of the graphene oxide is 1 mu m-5 mu m, the thickness of the graphene oxide is 0.8 nm-1.2 nm, and the particle diameter of a palladium nano particle is 3 nm-8 nm. The graphene oxide-supported Schiff base palladium catalyst can be used for preventing the palladium from losing in a catalysis process, meanwhile, the graphene oxide has a unique two-dimensional planar structure and can also be used for improving dispersing performance of the palladium nano particle on the surface of the graphene oxide to prevent the palladium from gathering in the catalysis process, so that the catalytic activity of the supported type catalyst is improved. Therefore, the graphene oxide-supported Schiff base palladium catalyst disclosed by the invention can be used for preventing the palladium from gathering and losing better in a catalytic C-C (Carbon-Carbon) coupling reaction process, and has higher catalytic activity and better recycling performance.

The present invention provides a method for making substituted indole compounds of general formula III comprising the step of:

(a) reacting a 2-bromoaniline or 2-chloroaniline of general formula (I)

(I)

wherein: X, R and R₁ are defined herein

with a substituted acetylene of formula (II)

wherein R₂ and R₃ in the presence of a palladium catalyst, a ligand, and a base in a solvent at a suitable temperature to give a compound of formula (III);

The invention discloses preparation and applications of a supported palladium catalyst using a MOFs derived carbon-based material as a carrier, and belongs to the technical field of catalyst material preparation. According to the present invention, ZIF-67 is adopted as a template, reduced palladium nanoparticles are uniformly supported in the pore channels in the ZIF-67 during a ZIF-67 synthesis process, and under a nitrogen protection condition, the carbon-based nanometer material supported palladium catalyst having excellent catalysis performance is constructed through high temperature carbonation; the preparation method of the invention is simple and easy to perform; and the prepared catalyst maintains the high specific surface area and the abundant pore structure characteristics of the precursor ZIF-67 to a large extent, such that the uniform dispersion and the stabilization of the palladium nanoparticles are easily achieved, and the excellent catalytic activity is provided.

A degassing device (10), a hydrogen dissolving device (12), and a palladium catalyst column (17) are provided in that order downstream of a high-purity water production device (1), and an impurity removal device (19) is connected to the exit side of treated water of the palladium catalyst column (17). The impurity removal device (19) removes impurity ions which are eluted into the water to be treated or impurity particulates which mix in with the water to be treated during the treatment in the palladium catalyst column (17). The impurity removal device (19) comprises an ion exchange device (20) and a membrane treatment device (21) such as a ultrafiltration membrane device, a reverse osmosis membrane device or the like. By providing an impurity removal device (19) in this manner, it is possible to remove impurities generated during hydrogen peroxide removal treatment by the palladium catalyst and to prevent degradation in quality of hydrogen-dissolved water.

A method for preparing diaminonaphthalene by catalytic hydrogenation of dinitronaphthalene relates to a preparation technology of the diaminonaphthalene, which comprises the following steps: adding a palladium catalyst comprising active components and a carrier and adding the dinitronaphthalene and solvent to a stainless steel high-pressure reactor with an agitator, closing the reactor, replacing air in the reactor with nitrogen for at least three times and then replacing the nitrogen in the reactor with hydrogen for at least three times, and then filling the hydrogen in the reactor so that the reaction pressure in the reactor reaches 0.4-4.0MPa, heating the reactor so that the reaction temperature reaches 30-150 DEG C so as to carry out catalytic hydrogenation to prepare the diaminonaphthalene. The method adopts the hydrogenation reaction technology in the stainless steel high-pressure reactor with the agitator; a catalyst carrier is pretreated to improve the activity of the catalyst and reduce the consumption of the catalyst. By optimizing the technological conditions, the rate of conversion from the dinitronaphthalene to the diaminonaphthalene is effectively improved and high selectivity of the product diaminonaphthalene is maintained.

The invention relates to a method for selective hydrogenation of reforming generated oil. According to the reforming generated oil, the bromine index is 7270mgBr/100g oil, and the weight of arene is 66.83%; the reaction conditions are as follows: the reaction temperature is 170 DEG C, the hydrogen partial pressure is 1.6MPa, the speed of liquid is 4h<-1> and the volume ratio between hydrogen and oil is 200. The method is characterized in that the used catalyst is Pd/gamma-Al2O3 containing 0.3wt% of palladium, and is passivated by a dry method with sulfur-containing compounds such as dimethyl disulfide, methyl thioether, butyl mercaptan or hydrogen sulfide before being filled; the added amount of the sulfide for passivation is as follows: the molar ratio of the palladium and the sulfur is 1-3.5; and the passivation temperature ranges from normal temperature to 230 DEG C. The method has the advantages that the pollution can be reduced, the investment can be reduced, convenience is brought for starting operation; after the palladium catalyst is passivated by the sulfide, the loss of arene of a hydrorefined product is lower than 0.5% (weight); after short-time reaction, the bromine index of the product is lower than 100 and the requirement of arene extraction for the raw materials can be met.

A method of preparing a supported platinum and/or palladium electrocatalyst and the electrocatalyst produced thereby. The method comprises the contacting of an electrically conductive particulate support which comprises adsorbed polynuclear hydroxo complexes of platinum and/or palladium with a reducing agent. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

The invention discloses a supported palladium catalyst and a preparation method thereof. The catalyst comprises a carrier, aid ingredients and an active ingredient, wherein the carrier is gamma-aluminum oxide, the aid ingredients are lanthanum and manganese or lanthanum and cobalt, and the active ingredient is palladium; the palladium load capacity is 0.2 wt% to 0.8 wt%, the lanthanum load capacity is 0.5 wt% to 1.5 wt%, and the manganese or cobalt load capacity is 0.2 wt% to 0.5 wt%. According to the catalyst, the carrier is modified with aids subjected to vacuum adsorption drying, and a proper amount of the manganese or the cobalt is added, so that the growth of Al2O3 crystal particles during high-temperature treatment can be inhibited, the specific surface area of the catalyst is enlarged, the Pd dispersity is improved, the alkalinity of the carrier surface is enhanced, the Pd concentration of the catalyst surface is increased, the Pd layer thickness is reduced, and the hydrogenation activity and selectivity of the catalyst are improved; meanwhile, the prepared catalyst is high in mechanical strength, uniform in aperture distribution and low in impurity content.