Modification method for raney nickel catalyst for p-chloronitrobenzene hydrogenation

Abstract

The invention relates to a modification method for a raney nickel catalyst for p-chloronitrobenzene hydrogenation, and belongs to the technical field of organic synthesis. According to the method, a catalyst is added to deionized water containing 1-5% of a modifier, a stirring reaction is performed for 20-40 minutes at a temperature of 30-70 DEG C, and a standing treatment is performed for 30-90 minutes; a reduction agent with the concentration of 5-15% is added, a stirring reaction is performed for 30-60 minutes at the temperature of 40-50 DEG C, and NaHCO3 is adopted to adjust the pH value to 8-10, wherein a mass ratio of the reduction agent to the raney nickel catalyst is 4:1-8:1; a standing treatment is performed for 30-60 minutes, and deionized water is adopted to wash until the solution is neutral, a filtering treatment is performed, water is added, and sealed preservation is performed to prepare the modified raney nickel catalyst. According to the present invention, under the condition of no addition of the dechlorination inhibitor, the p-chloronitrobenzene conversion rate is more than or equal to 99.9%, the dechlorination side reaction generation rate in the p-chloronitrobenzene hydrogenation process is less than or equal to 2%, and the yield of p-chloroaniline is more than or equal to 95%; compared to the existing methods for preparing the hydrogenation catalyst, the method of the present invention has the following advantages that: the hydrogenation process is simplified, the three waste is less after the hydrogenation, the cost is low, the energy consumption is low, and the industrial requirements of quality increasing, consumption reducing, and environmental protection are achieved.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and proposes a method for modifying and modifying a skeleton nickel catalyst for hydrogenation of p-chloronitrobenzene. Background technique [0002] Nickel (Raney Ni) is an extremely important catalyst for hydrogenation. It has been widely used in the hydrogenation process, such as the hydrogenation of alkynes, alkenes, aryls, carbonyls, nitro groups and nitrile groups. The quantity is also larger. The catalytic reaction process of nickel catalyst is roughly divided into four steps: (1) hydrogen adsorption on the surface of nickel metal particles and split into hydrogen atoms; (2) adsorption of reactants; (3) surface reaction; (4) product desorption. Therefore, in the hydrogenation process, the activity and service life of the Raney nickel catalyst directly affect the quality, yield and economic benefits of the product. With the improvement of catalyst performance requirements in the...

AI Technical Summary

Problems solved by technology

However, there are few studies on the modification of later-stage framework nickel catalysts.

However, the requirements for framework nickel catalysts in organic chemical hydrogenation processes are different, which prevents framework nickel catalysts from being more widely used in various hydrogenation processes.