82 results about "Catalytic transfer hydrogenation" patented technology

The invention relates to a catalyst for preparing p-aminophenol through catalytic hydrogenation of p-nitrophenol, and a preparation method thereof, and belongs to the technical field of catalysis. The carrier of the catalyst is a ceramic membrane, and the preparation method comprises the following steps of: modifying the membrane surface by using aminosilane; immersing in salt solution of an active ingredient; and performing hydrazine hydrate reduction to prepare a catalytic membrane. The invention has the advantages that: nano-scale catalyst particles are supported on the surface of the ceramic membrane modified by silane, and the activity and stability of the catalyst are improved; moreover, a problem that the catalyst is hardly separated from the product subsequently is avoided. The catalyst is simple in preparation process and high in activity and stability and can be widely applied to preparing the p-aminophenol through catalytic hydrogenation of the p-nitrophenol.

The present invention provides an improved process for preparation of 2-phenyl ethanol. More specifically, the present invention relates to a process for preparing 2-phenyl ethanol by catalytic transfer hydrogenation of styrene oxide, in the presence of a supported transition metal catalyst. The catalyst system comprises of a palladium supported on silica, alumina, clay or charcoal.

Methods for the production of hydrogen comprise heating a hydrogen-bearing feed material capable of undergoing a hydrogenation reaction in the presence of a hydrogen donor material, a catalyst promoting catalytic transfer hydrogenation, and a base at a temperature of from about 150° C. to about 450° C. for a time sufficient to hydrogenate the feed material and to dehydrogenate the hydrogenated feed material to produce hydrogen and carbon, and collecting the resulting hydrogen.

The invention discloses a modified nickel silicon catalyst and application thereof in preparation of gamma-butyrolactone (GBL) by means of catalytic hydrogenation of maleic anhydride. The active component of the catalyst is metal Ni, one or two of reducible metal oxides CeO2 ZnO and MoO3 is / are used as additive(s), and SiO2 is taken as a carrier, wherein the mass ratio of the metal Ni to the additive(s) to the SiO2 is equal to 1 to (0.04-0.7) to (2-3.2). A preparation method of the catalyst comprises the following steps: mixing a nickel salt with an additive precursor metal salt solution in proportion, and then adding ammonia water into the metal mixture to form a metal ammonia complex; then, dropwise adding alkaline silica sol into the complex mixed solution, and precipitating by using aheating ammonia distillation method; filtering the obtained precipitate, washing, drying and calcining to obtain the oxidized state modified nickel silicon catalyst which is abbreviated as a Ni-M-PS catalyst. The catalyst can be used for preparation of the GBL by means of the catalytic hydrogenation of the maleic anhydride, has higher catalytic activity and stability, and has a potential industrial application value.

The invention discloses a process for preparing hexahydrophthalic anhydride (HHPA) by means of catalytic hydrogenation. The process includes preparing Pd-NiO / SiO2 catalysts by the aid of impregnation processes by SiO2 used as a carrier; catalytically hydrogenating tetrahydrophthalic anhydride in a trickle-bed reactor to prepare the hexahydrophthalic anhydride (HHPA). The process has the advantages that the optimal reaction conditions and process parameters are explored; the SiO2-supported Pd and Ni binary-metal catalysts are adopted, the activity of the catalysts is appropriately deteriorated, the hydrogen partial pressures are increased, and accordingly the selectivity of the hexahydrophthalic anhydride (HHPA) which is a target product can be effectively improved; hydrogen can flow into the trickle-bed reactor from an upper location, a middle location and a lower location, accordingly, reaction layout is uniform and controllable, and side reaction can be reduced; heat generating reaction is carried out during catalyst hydrogenation, the internal circulation speed of the hydrogen in the reactor can be increased, the hydrogen is used as a heat transfer medium, accordingly, reaction heat can be timely transferred, local overheating phenomena can be effectively prevented, and the side reaction can be reduced.

The invention relates to a method for preparing lubiprostone. The method comprises the following steps: by taking triethyl silicane as a hydrogen source, and taking palladium carbon or palladium hydroxide as a catalyst, performing catalytic transfer hydrogenation, removing the protecting groups, and reducing double bonds, thereby obtaining the product. Compared with a conventional catalytic hydrogenation reaction at present, the method has the advantages of simplicity in operation, mild reaction conditions, high yield and high purity, the reaction time and reaction period are obviously shortened, the production efficiency is greatly improved, the requirements on reaction equipment are reduced, and the method is suitable for industrial production.

The invention discloses a carbon-supported basic ionic liquid-metal catalyst as well as preparation and application thereof in catalytic transfer hydrogenation reaction. The carbon-supported basic ionic liquid-metal catalyst is composed of an activated carbon carrier, basic ionic liquid and metal, wherein the basic ionic liquid and the metal are loaded on the carrier. The metal is palladium or platinum. The catalyst can be prepared by the following steps: performing alkali treatment on an activated carbon carrier to weaken acidic groups on the surface of the activated carbon carrier, loading ametal precursor salt and an alkaline ionic liquid onto the surface of the pretreated activated carbon by wet impregnation, performing drying, and reducing with a reducing agent to obtain the carbon-supported alkaline ionic liquid-metal catalyst. The invention provides an application of the basic ionic liquid-metal catalyst in a reaction for synthesizing a benzotriazole ultraviolet absorbent shownin a formula (II) through catalytic transfer hydrogenation of an azo intermediate shown in a formula (I) (the formulas are shown in the specification), and the selectivity of a target product can beremarkably improved under the condition that an alkaline auxiliary agent is not added.

The invention discloses a method for catalytic hydrogenation of heavy crude oil by using methane. Heavy crude oil is pumped into a hydrogenation reactor containing catalysts; methane is used as reaction gas for catalytic hydrogenation reaction; macromolecules in the heavy crude oil are decomposed into alkane and light-weight aromatic compounds; product oil flows out from a lower side of the hydrogenation reactor and is introduced into a gas-liquid separation tank for gas-liquid separation; tail gas flows out from the pipeline from the top of the gas-liquid separation tank and is used for subsequent treatment; product oil flows into a product tank from the bottom of the gas-liquid separation tank to be collected; the gas liquid separation tank is connected with a cooling system for reducingthe temperature of the product oil; the viscosity of the obtained product oil is 107 to 379 mPa.s; the density is 0.9511 to 0.9642 g / ml; the total acidity is 0.02 to 1.55 mg KOH / g; the average molecular weight is 172 to 210 g / mol; the water content is 0.21 to 0.30 weight percent; the product liquid yield is 96.9 to 104 percent. The operation cost of the technical flow process is reduced; the hydrogenation reaction effect is effectively improved; the operation pressure is reduced; a green and environmental-friendly process is achieved.

The present invention provides processes for the stereoselective synthesis of 6-alpha-amino morphinans. In particular, the invention provides processes for the reductive amination of 6-keto normorphinans by catalytic transfer hydrogenation.

The invention provides a silicon-containing diphenol and a preparation method thereof, wherein a structure of the silicon-containing diphenol is represented as the formula (I). The preparation method includes following steps: (A) with di-substituted divinyl silane as a raw material, performing a catalytic olefin double-decomposition reaction with vinylphenol to obtain an intermediate, di-substituted bis(hydroxylstyryl)silane; (B) performing catalytic hydrogenation and catalytic transfer hydrogenation to obtain di-substituted bis(hydroxylphenethyl)silane, which is the silicon-containing diphenol in the invention. The silicon-containing diphenol represented in the formula (I) is excellent in toughness, flame resistance and heat resistance. The preparation method is simple in operation, is mild in conditions, is high in product yield, is low in cost, is green and environment-friendly, and is high in industrialization value.