787results about How to "Improve catalytic selectivity" patented technology

The invention relates to a copper bismuth catalyst for combining chemically into 1, 4-butynediol with formaldehyde and ethyne and a preparation method thereof. The preparation method comprises the following steps of: preparing mixed solution which contains copper salt, bismuth salt, magnesium salt and dispersant; dropping alcoholic solution with an organic silicon source into the mixed solution; adjusting a pH value of the mixed solution with alkaline solution to obtain mixed precipitate; and further aging, washing, drying and baking in inert atmosphere to obtain the copper bismuth catalyst with C-MgO-SiO2 a carrier, in the catalyst, the content of CuO accounts for 25-50 weight percent, and the content of Bi2O3 accounts for 2-6 weight percent. The catalyst is applied in a reaction of combining chemically into 1, 4-butynediol with formaldehyde and ethyne, and has high catalytic activity and high selectivity.

The invention relates to synthesis of first-class phosphorus functionalized polyether alkyl guanidinium ionic liquid, and an application of the first-class phosphorus functionalized polyether alkyl guanidinium ionic liquid in a homogeneous catalytic reaction. The functionalized ionic liquid of such class can be easily prepared by an ion exchange reaction between the polyether alkyl guanidinium ionic liquid and sulfonic acid type water soluble phosphine ligand. The designed phosphorus functionalized ionic liquid can be applied to organic reactions, including hydroformylation, hydroesterification, hydrocarboxylation and catalytic hydrogenation under the catalyzing of a transition metal; the dosage of the ionic liquid used in the catalytic reaction can be decreased; the activity of the catalytic reaction can be improved; a catalyst can be separated and cycled simply and conveniently.

The invention provides a method for preparing a butanediol secondary hydrogenation catalyst through adopting the butynediol two-step hydrotreation, and the method comprises the following steps: an accelerant is introduced into an alumina carrier; the carrier is heated; mixed nickel complex solution containing organic nickel salt, inorganic nickel salt and surfactant is prepared; the mixed nickel salt solution is dipped on the heated carrier, and the catalyst product with the nickel content of 5-25 w% and the accelerant content of 0.001-6 w% can be obtained by drying, baking, deoxidizing and passivating. The catalyst can be used in the process of preparing the butanediol secondary hydrogenation by adopting the butynediol two-step hydrotreation, the carbonyl can be reduced to be lower than 0.2 mg (KOH)*g<-1>, and the contents of acetal and butylene glycol are enabled to be reduced to the lowest level. Through the subsequent rectification, the butylene glycol product with the purity more than or equal to 99.5 percent and the chromaticity lower than or equal to 10 AHPA can be produced.

The invention discloses a porous carbon-loaded composite material catalyst as well as a preparation method and application thereof. The catalyst consists of a carrier, an active component and a carbon quantum dot, wherein the active component and the carbon quantum dot are loaded on the carrier; the size of the carbon quantum dot is not more than 10 nm; the carrier is porous activated carbon; the active component is one of or a combination of several of platinum, palladium, iridium, ruthenium and rhodium; based on the mass of the carrier, the loading quantity of various metals in the active component is shown as follows: the platinum is 0-10.0 percent by weight, the palladium is 0-10.0 percent by weight, the iridium is 0-10.0 percent by weight, the ruthenium is 0-10.0 percent by weight, and the rhodium is 0-5.0 percent by weight; the loading quantity of the platinum, the rhodium and the palladium is not 0; the total loading quantity of the active component is more than 0.5 percent by weight and is not more than 20 percent by weight; based on the mass of the carrier, the loading quantity of the carbon quantum dot is not more than 15.0 percent by weight. The invention further provides application of the porous carbon-loaded composite material catalyst to the reaction of synthesis of chloroaniline by selective catalytic hydrogenation of chloro-nitrobenzene. The catalyst has the characteristics of being high in conversion rate, high in catalytic activity and high in stability.

During the preparation process of phosphorus containing beta-zeolite, work water solution compounded with aluminum source, alkali source and tetraethyl ammonium cationic solution is mixed with silica gel of granularity 20-300 mesh as silicon source to moisten the surface of the silica gel grain; the mixture is maintained at 80-140 deg.c for 20-80 hr to obtain crystal seed colloid; aluminum phosphate in the amount of 5-30 wt% of the crystal seed colloid is thrown into the crystal seed colloid, and through homogeneous mixing, crystallization at 140-170 deg.c for 50-100 hr, separation of solid matter, washing to Na2O content less than 0.1 wt% and drying, phosphorus containing beta-zeolite is prepared. The beta-zeolite product may contain phosphorus up to 5 wt% and has relatively high catalytic selectivity when being used in alkylation.

The invention relates to a method for preparing dicarboxylic acid, in particular to a method for preparing adipic acid by biomimetic catalyzing oxygen oxidation of cyclohexane. The present invention selects metallophthalocyanines, mononuclear metalloporphyrins or μ-oxygen-binuclear metalloporphyrins similar in structure to biological enzymes as catalysts, and the dosage thereof is 0.1 to 1‰ of the weight of cyclohexane. As a solvent, 0.5-3.5 MPa of oxygen is passed through, the reaction temperature is controlled to be 110-160° C., and the reaction time is 4-32 hours. In the invention, the amount of catalyst is small, the reaction temperature and pressure are low, and the oxidation depth is easy to control. The catalysts used have good catalytic properties for the reaction of oxygen oxidation of cyclohexane to prepare adipic acid. The catalyst can be recycled to reduce the preparation cost. The invention adopts a one-step method to prepare adipic acid, and the reaction operation is simple and easy.