11 results about "Raney nickel" patented technology

This invention relates to a method for preparing hexamethylenediamine by hydrogenation of adiponitrile in the presence of a Raney nickel catalyst, wherein a Raney nickel catalyst modified by treatment with carbon monoxide or carbon dioxide in a liquid medium is used.

The embodiment of the present application discloses a preparation method of nor-tropine alcohol. The method comprises the following steps: performing demethylation reaction on tropinone and chloroethyl chloroformate in the presence of a solvent, performing vacuum concentration and evaporation, and obtaining demethyltropinone; performing reduction reaction on the demethyltropinone and lithium tri-t-butoxyaluminum hydride in the presence of a solvent, and obtaining the nor-tropine alcohol. The present application adopts a new type of reducing agent lithium tri-t-butoxyaluminum hydride, which is safe, not sensitive to air and water, and simple in post-treatment, thus avoiding safety hazards from the source. The present application avoids the use of dangerous Raney nickel and does not need to use an autoclave, so that the production capacity is greatly improved. The present application performs the reaction under low-temperature conditions, is low in energy consumption, can effectively reduce production cost, and is moderate in reaction conditions, safe and simple in operation, and is conducive to large-scale industrial production.

The application provides a Raney nickel electrode and a preparation method and application thereof, and relates to the field of hydrogen production by electrolysis of water. An electrode substrate with a Raney nickel catalytic layer on the surface is subjected to heat treatment to obtain a heat-treated electrode; an alkali solution, an additive and the heat-treated electrode are mixed, activated, washed and dried to obtain the Raney nickel electrode; the volume concentration of oxygen in the heat treatment is gradually reduced until a low-oxygen atmosphere or an oxygen-free atmosphere, and the temperature is gradually increased. By introducing a controllable gradient heat treatment process before alkali activation, sufficient diffusion between Ni and Al is promoted to form a specific content stable Ni3Al phase, the Ni-Al synergistic structure in the Ni3Al phase can regulate the surface electronic structure to a certain extent, improve the distribution of active sites on the electrode surface, and improve the hydrogen evolution and oxygen evolution performance. In addition, while ensuring the integrity of the porous electrode skeleton structure, the alloying degree is improved.

The application discloses a method for preparing trimethylolamine by a continuous flow method, and comprises the following steps: mixing polyformaldehyde and alkali to obtain a mixed solution 1; mixing a nitromethane solution and the mixed solution 1 to form a reaction solution, and then introducing the reaction solution into a micro-channel continuous flow reactor to obtain a mixed solution 2 after reaction; adjusting the flow rates of the mixed solution 2 and hydrogen, and then mixing the gas-liquid mixture into a gas-liquid mixer at the inlet of a micro-packed bed continuous flow reactor, passing through a catalyst bed layer of the micro-packed bed continuous flow reactor to react, and then adjusting the temperature through a reactor heat exchange cavity of the micro-packed bed continuous flow reactor to obtain a crude product after reaction, and then performing post-treatment and purification to obtain a trimethylolamine product; and the catalyst comprises a supported Pd catalyst, a supported Ni catalyst or a Raney nickel catalyst. The preparation method of the application enables the solid catalyst to fully contact with the mixed solution 2 and hydrogen, compared with a conventional intermittent hydrogenation preparation method, the reaction time is shortened, the product purity is high, the safety is high, and the method is beneficial to industrialized scale production.

The application discloses a flexible polyimide film and a preparation method thereof, and relates to the technical field of polyimide films. In the preparation of the flexible polyimide film, 4,4'-(oxybis(methylene))bis(chlorobenzene) and 4-nitrophenol are reacted to obtain a dinitro intermediate; the dinitro intermediate is reduced by Raney nickel to obtain an ether-containing diamine monomer; 5-bromo-1,3-diaminobenzene and 3,5-bis(trifluoromethyl)phenylboronic acid are reacted to obtain a fluorine-containing monomer; gamma-aminopropyltriethoxysilane is hydrolyzed and grafted on the surface of boron nitride to obtain modified boron nitride; and the ether-containing diamine monomer, the fluorine-containing monomer, the modified boron nitride and pyromellitic dianhydride are in-situ polymerized to obtain the flexible polyimide film. The flexible polyimide film prepared by the application has excellent insulation, heat dissipation performance and mechanical flexibility.

The application discloses a preparation method of 3-chloro-5-fluoro-2-methylbenzoic acid, relates to the technical field of 3-chloro-5-fluoro-2-methylbenzoic acid production, and the method is characterized in that: 2-methyl-5-nitrobenzoic acid is used as a starting raw material, selective chlorination is carried out on the starting raw material in preheated high-temperature concentrated sulfuric acid and dichloro hydantoin, then esterification is completed by a one-pot method, catalytic hydrogenation reduction is carried out under low-pressure and low-temperature conditions by the synergistic action of a Raney nickel catalyst and a platinum-carbon catalyst, a high-purity amino intermediate is obtained, smooth thermal decomposition fluorination is carried out in a diglycol dimethyl ether solvent, alkaline hydrolysis and refinement are carried out, and finally the end product is obtained; the product has high purity and high yield.

The application discloses a synthesis method of indole-2-carboxylic acid, which is suitable for industrial production and comprises the following steps: (1) condensation: mixing o-nitrotoluene, diethyl oxalate and sodium ethoxide ethanol solution, raising to 75-85 DEG C and reacting for 1.5-3 hours, adding into water, stirring for 0.5-1.5 hours, removing ethanol, decoloring, filtering, adjusting the pH of the filtrate to 1-2, and obtaining an intermediate; (2) reduction: adding methanol to the intermediate, adding Raney nickel, raising to 55-65 DEG C, adding hydrogen and reacting, lowering to room temperature, filtering, removing methanol, lowering to 0-5 DEG C and preserving for 1-2 hours, and filtering to obtain a crude product; and (3) purification: adding water to the crude product, adjusting the pH to 8-9, decoloring, filtering, adjusting the pH to 2-3, precipitating a solid, filtering, and drying the filter cake.

The application discloses a catalyst for hydrogenation of pimelidic acid dinitrile to pimelidic acid diamine and a preparation method and application thereof, and belongs to the technical field of fine chemical synthesis and catalytic material. The catalyst is prepared as follows: magnesium-aluminum composite oxide LDO and cerium nitrate hexahydrate are stirred and dissolved in water, and then reacted at pH of 9-10; after reaction, suction filtration is carried out; after calcination, a CeO2-LDO composite carrier is obtained; the CeO2-LDO composite carrier and nickel nitrate hexahydrate are dissolved in water, and then reacted at pH of 12-13; after reaction, suction filtration is carried out; after drying, reduction calcination is carried out, and a Ni / CeO2-LDO catalyst is obtained. In the process of using the catalyst for hydrogenation of pimelidic acid dinitrile to pimelidic acid diamine, the reaction condition temperature is low, and the catalyst consumption is small; the conversion rate of pimelidic acid dinitrile is greater than or equal to 99%, the selectivity of pimelidic acid diamine is greater than or equal to 99%, the performance is better than that of a traditional Raney nickel catalyst, the catalyst has excellent cycle stability, and the demand of industrial continuous production can be met.

The application discloses an FeCoNiMnCr high-entropy alloy oxygen evolution electrode and a preparation method and application thereof, and belongs to the field of hydrogen energy technology and new materials. The preparation method comprises the following steps: mixing Fe, Co, Ni, Mn and Cr metal elements in proportion, vacuum smelting and gas atomization to obtain high-entropy alloy powder; mixing the high-entropy alloy powder with aluminum powder, and then spraying the mixture to a nickel mesh substrate by means of plasma spraying; performing heat treatment in an inert atmosphere; and forming a high-entropy alloy electrode with a three-dimensional porous structure through alkali leaching. The electrode prepared by the application has excellent mechanical stability, high oxygen evolution catalytic activity and excellent chemical stability, and has the characteristics of low overpotential and long service life in the preparation of hydrogen by alkaline water electrolysis. The oxygen evolution overpotential of the electrode is reduced by 80-120 mV compared with that of a traditional Raney nickel electrode under a current density of 500 mA / cm2, and the voltage change rate is less than 2.5% in a 500-hour stability test. The process is simple and controllable, is suitable for large-scale industrial production, and can be widely applied to the fields of green hydrogen preparation and alkaline water electrolysis hydrogen production systems.

This invention relates to the field of co-production synthesis technology and discloses a co-production synthesis process for N,N,N'-trimethyl-N'-hydroxyethyl diaminoethyl ether and bis(dimethylaminoethyl) ether. Using methylethanolamine, concentrated sulfuric acid, ethylene oxide, paraformaldehyde, and hydrogen as raw materials, the process involves sequential BMAEE synthesis, hydroxyethylation reaction, methylation reaction, and distillation purification steps to achieve co-production. Raney nickel is used as a catalyst in the methylation reaction. The Raney nickel catalyst is recycled and regenerated through rare earth modification, and then reused. The rare earth modification and regeneration involves adding lanthanum oxide to the recycled Raney nickel catalyst for low-temperature modification. The catalytic activity of the modified and regenerated Raney nickel catalyst can be restored to more than 95% of that of the fresh catalyst, enabling multiple reuses. This not only significantly reduces the raw material procurement cost of the catalyst but also reduces the amount of solid waste generated from spent catalysts.

The application discloses a kind of phosphorus-containing noble metal coating's alkaline electrolytic water hydrogen production electrode and preparation method, electrode includes Raney nickel base material, inner layer cobalt-nickel-phosphorus-boron protective layer, intermediate ruthenium-based catalytic layer and outer layer cobalt-nickel-phosphorus-boron catalytic layer, form " sandwich " coating structure.When preparing, first, through chemical plating, inner layer protective layer is deposited on substrate, then, through immersion replacement method, intermediate ruthenium-based catalytic layer is deposited in the immersion solution containing ruthenium ions, after sintering treatment, outer layer catalytic layer is deposited, immersion solution can be recycled and reused after replenishing ruthenium salt, improve ruthenium utilization rate;Through the double protection of inner and outer layers to intermediate ruthenium layer, the long-term operation stability of electrode under industrial current density is significantly improved, while the amount of noble metal is greatly reduced, high catalytic activity and low cost are considered.