43 results about "Rhodium compounds" patented technology

The invention discloses a catalyst for producing aldehyde through hydroformylation of alkene, wherein, the catalyst comprises ionic organic phosphorus ligands and rhodium compounds; the molar ratio of the ionic organic phosphorus ligands and the rhodium compounds is 1 to 20:1; the ionic organic phosphorus ligands are ionic compounds and comprise positive ions and negative ions; the rhodium compounds are neutral rhodium complexes or ionic rhodium compounds; the catalyst is used for catalyzing the reaction of aldehyde preparation through hydroformylation of alkene, wherein, the related alkene is Alpha-alkene that is a straight chain of C3 to C12; and an adopted solvent is room-temperature imidazolyl or pyridyl ionic liquid. The catalyst is characterized by favorable catalytic performance, prolonged service life and circulating application in the liquid phase reaction of aldehyde production through hydroformylation of alkene.

The invention provides a preparation method of an aromatic compound hydrogenation rhodium/activated carbon catalyst. The preparation method comprises the following steps: I, pretreating activated carbon; II, dissolving soluble salts of a soluble rhodium compound and an additive into a solvent so as to obtain a precursor solution; III, atomizing and dispersing the precursor solution, adding into the activated carbon, uniformly stirring so as to obtain slurry, adjusting the pH value of the slurry, filtering, and washing; IV, pulping with pure water, performing reduction treatment, and performing treatment of filtration, washing and drying in sequence, thereby obtaining the aromatic compound hydrogenation rhodium/activated carbon catalyst. The invention further provides an application method of the catalyst. The catalyst prepared by using the method consists of activated carbon and metal components loaded on the activated carbon, the metal components are rhodium and an additive, the catalyst is applicable to catalytic hydrogenation of aromatic compounds, the product yield is higher than 95%, and the catalyst is stable in property and very high in repeatability.

The invention discloses a method for preparing an acetic acid and an acetic anhydride respectively and synchronously, which is characterized in that: a methanol, a methylacetate or a mixture of the methanol and the methylacetate and a mixed gas of carbon monoxide and hydrogen are reacted at 150 to 250 DEG C and 2.0 to 6.0 MPa; and a catalyst system used in the reaction comprises a mixture of rhodium or one of rhodium compounds and iridium or one of iridium compounds, a methyl iodide, at least one selected from mixtures of an amino acid and an amino acid derivative, the amino acid or the aminoacid derivative, and an accelerant. The method for preparing the acetic acid and the acetic anhydride in the invention has the advantages of: (1) reducing the generated tar, (2) reducing substance content of the acetic anhydride product, and (3) improving the stability of the catalyst system in the invention and avoiding the precipitation phenomenon. Due to the fact that the reaction system has no water, the corrosion to devices is also reduced.

The invention discloses a preparation method of rhodium compounds. According to the method, bis(1.5-cyclooctadiene) rhodium(I) tetrafluoroborate compounds are synthesized in two steps, firstly, 1.5-cyclooctadiene rhodium chloride dimmers are synthesized with rhodium chloride trihydrate as raw materials; secondly, the bis(1.5-cyclooctadiene) rhodium(I) tetrafluoroborate compounds are synthesized with the 1.5-cyclooctadiene rhodium chloride dimmers as raw materials. The one-way total yield is 93% or above, operation is easy, industrial production can be achieved, and certain economic benefits are achieved.

The invention relates to a catalyst system used for methanol low-pressure carbonyl synthesis of acetic acid, which uses rhodium compounds as the active component carbonylation of carbonyl synthesis catalyst and uses alkyl iodide, water, hydroiodic acid, alkali metal iodate and sulfonate as promoters, and uses acetic acid as polar solvent. Because sulfonate is added to the catalyst system, better catalytic activity and stability are achieved. In methanol carbonylation, the catalyst system can convert methanol into acetic acid at high speed with high selectivity under lower temperature and pressure. The reaction reduces the concentration of water and hydroiodic acid, and reduces corrosivity to equipment.

The invention relates to a method for preparing isononanal through diisobutylene hydroformylation, wherein the method comprises the steps: firstly, adding a rhodium compound and two organic phosphine ligands (LA and LB) in an optional appropriate solvent into a self-control high-pressure reaction kettle, mixing to prepare a catalyst solution, introducing nitrogen for replacement for three times, evacuating the reaction kettle, adding a certain amount of diisobutylene through a feeding pump, stirring and heating, after the temperature of the reaction system is stable, introducing synthesis gas to a set reaction pressure, and carrying out timing reaction; and after the reaction is finished, naturally cooling the reaction kettle, and adding an internal standard substance for sampling analysis. According to the method, the catalyst has good catalytic activity on 4,4,2-trimethyl-1-pentene and 4,4,2-trimethyl-2-pentene in diisobutylene, the single-pass olefin conversion rate can achieve 99% or more, and the aldehyde yield can achieve 97% or more. The method for preparing isononanal from diisobutylene has the advantages of simple process, mild reaction conditions and high yield of the product isononanal, and is suitable for industrial production.

The invention relates to a method for measuring the rhodium content in rhodium-containing compound. The method comprises the steps of: 1) roasting by using high-temperature air to decompose rhodium-containing compound to be rough rhodium oxide; 2) grinding the rough rhodium oxide, immersing with 1-6mol/L hydrochloric acid for 1-5h at 50-70 DEG C and filtering to obtain filter residue; 3) reducing the filter residue with high-temperature nitrogen to change the rhodium oxide into rhodium powder; 4) weighing the rhodium powder and calculating rhodium content in the rhodium-containing compound. By adopting the method, rhodium content in the rhodium-containing compound with regular rhodium content which can be decomposed to be oxide by heating can be accurately measured, addition of other reagents for separation of rhodium is not needed, measuring error caused by repeated dilution with a power-spectral method is avoided, and rigorous requirements of high-temperature and strong-oxidizing-property wet digestion on the equipment are avoided. The method is convenient to operate without introducing solid impurities and has the advantages of high accuracy and recovery rate.

The invention discloses a monatomic rhodium catalyst as well as a preparation method and application thereof. The monatomic rhodium catalyst is a doped monatomic catalyst, and the chemical formula of the monatomic rhodium catalyst is Ti(1-x)RhxO2, wherein x is greater than or equal to 0.001 and less than or equal to 0.1. The preparation method comprises the following steps: uniformly mixing a rutile type titanium dioxide precursor with a rhodium-containing compound, conducting calcining at high temperature, and performing cooling to room temperature to obtain the monatomic rhodium catalyst. The preparation method disclosed by the invention has the characteristics of simple process, low requirements on production equipment and capability of realizing large-scale production, and the obtained monatomic rhodium catalyst has the advantages of stable chemical properties and physical structures, excellent catalytic performance and the like, and has a good large-scale application prospect; and the monatomic rhodium catalyst disclosed by the invention can be applied to the catalytic fields of hydrogen production by photocatalytic decomposition of water, carbon dioxide reduction, thermocatalysis, pollutant degradation and the like.

The invention provides a chiral bis-imidazoline pincer rhodium compound and an asymmetric addition reaction method of ethyl trifluoropyruvate with terminal alkyne under the catalysis of the compound. Optically active trifluoromethyl propargyl tertiary alcohol is synthesized in a high enantioselectivity mode. The rhodium compound is simple in preparation, easy to modify in structure and good in stability. During an asymmetric alkynylation reaction for catalyzing the trifluoroacetone acid, the catalyst dosage is few, the reaction temperature is mild and controllable, the application range of a substrate is wide, and the product- optically active trifluoromethyl propargyl tertiary alcohol has a high yield and an enantio-selectivity higher than 95% in most instances.

The invention discloses a carbonylation method for synthesizing acetic acid by combining rhodium and iridium, which comprises the following step: reacting a liquid-phase medium including methanol, methyl acetate, acetic acid and water with carbon monoxide to generate acetic acid, wherein the catalysis system used in the reaction is as follows: rhodium compounds and iridium compounds of group VIII are used as main catalysts, iodomethane is used as a catalyst promoter, and zinc salt is used as stabilizer. Because of the stabilizing effect of the zinc salt, the rhodium compounds and iridium compounds can achieve a synergetic effect without adding alkali metal salt or alkaline earth metal salt to stabilize the rhodium catalyst, thereby greatly improving the catalytic activity, reducing the water content in the reaction, respectively controlling the pressure and temperature within an ideal range, decreasing the production of byproducts, and stabilizing and smoothing the reaction process.

The present invention relates to a process for preparing mercaptoorganyl(alkoxysilanes), by hydrogenating bis(alkoxy-silylorganyl) polysulphides with hydrogen in the presence of at least one alcohol and a doped metal catalyst. The doped metal catalyst comprises at least one substance from the group consisting of iron, iron compound, nickel, nickel compound, palladium, palladium compound, osmium, osmium compound, ruthenium, ruthenium compound, rhodium, rhodium compound, iridium and iridium compound plus at least one doping component.

A bimetal Rh-Li catalyst for the hydroxylation reaction of methanol to obtain acetic acid or the carbonylating reaction of methyl acetate to obtain ethylanhydride is disclosed, which has 3 basic structures and features high activity, selectivity and stability. Its preparing process includes such steps as copolymerization of 2-vinylpyridine or 4-vinylpyridine on acrylic acid, acrylate, or maleic acid anhydride, hydrolzying by strong alkali, acting on lithium hydroxide to obtain ligand, reacting on Rh compound and coordination.

The invention provides a preparation method of high-purity rhodium powder. The preparation method of the high-purity rhodium powder comprises the following steps: 1. dissolving platinum-rhodium alloy in a mixed solution of concentrated hydrochloric acid and concentrated nitric acid, then heating the solution and carrying out acid and nitrate removal, and determining a nitrate removal degree; 2, adding alkali into the solution obtained in the step 1 to adjust the pH value to be 17, and filtering; 3, adding a reducing agent and a rhodium coordination agent into the filtrate obtained in the step 2, carrying out a heating reaction, and filtering to obtain a filter cake of a rhodium compound; 4, adding water into the filter cake obtained in the step 3 to carry out slurry mixing, adding alkali to adjust the pH value to be 17, and carrying out suction filtration after heating and stirring to obtain a high-purity filter cake of the rhodium compound; 5, dissolving the filter cake obtained in the step 4 with hydrochloric acid, then adjusting the pH value to 26 with sodium hydroxide, and slowly adding hydrazine hydrate for reduction to obtain rhodium black; and 6, introducing hydrogen into the rhodium black obtained in the step 5 for reduction to obtain the high-purity rhodium powder. According to the invention, the high-purity rhodium powder is prepared by rapidly purifying from the precious metal platinum-rhodium alloy, and the process is simple.

A stereospecific synthesis process for tretinoin compounds comprises the following steps: using substituted triphenyl phosphine salt and β-formyl crotonic acid as raw material to carry out WITTIG reaction under the action of alkali; then adjusting the pH of the reaction liquid to 5-10; adding palladium compound or rhodium compound to carry out isomerization directly and obtain tretinoin compounds with desired configuration. The product yield of the process is high and the intermediate product in the reaction dose not need to be separated. The process is easy to operate and can save the production cost and as well is suitable for industrial production.

The invention discloses a carbon nanometer tube loaded rhodium catalyst system and an application thereof. The carbon nanometer tube loaded rhodium catalyst system is characterized in that a carbon nanometer tube loaded rhodium compound is taken as active species; a halogen promoter is added; a high-concentration noble metal rhodium catalyst can exist in a reaction system in a carbonylation reaction through the carbon nanometer tube loaded rhodium catalyst; the pulp liquid phase reaction can be achieved; the carbonyl synthesis rate is increased and the noble metal loss is reduced; the catalyst provided by the invention can increase the carbonyl synthesis rate and the yield of industrial device.

The present invention relates to a method for producing hydrogenated nitrile rubber (HNBR) having good ageing properties in the presence of ruthenium, palladium or rhodium compounds and also to the hydrogenated nitrile rubber produced by this method and HNBR compositions thereof.

The invention discloses a graphite-phase carbon nitride-modified silicon oxide porous microsphere-supported heterogeneous rhodium catalyst and a preparation method and application thereof. The catalyst adopts a stable silicon oxide porous material as a framework and employs carbon nitride as a carrier for surface modification, a rhodium compound is adsorbed, and then high-temperature oxygen-free treatment is conducted so as to obtain the heterogeneous rhodium catalyst for a carbonylation reaction of methanol. Accordign to the invention, methyl alcohol can be carbonylated into acetic acid and methyl acetate under mild conditions without a solvent by using methyl iodide as a cocatalyst; the prepared catalyst is stable in performance and high in activity, supported rhodium is not easy to fall off, the catalyst is stable in structure, and rhodium loss is not easy to cause; and the catalyst can still maintain good activity after being repeatedly used 7 times or more, and is easy to recycle and reuse.