Preparation method of supported catalyst with high specific surface area and application of supported catalyst in paranitroaniline synthesis

Abstract

The invention discloses a preparation method of a supported catalyst with a high specific surface area, the method comprises the following steps: dispersing porous nano silicon oxide in deionized water, then adding an aniline monomer under an ice-water bath condition, uniformly mixing, then adding an ammonium persulfate solution, stirring to react, filtering the reaction liquid after the reaction is finished, washing the precipitate with deionized water, drying, and calcining the dried solid in a muffle furnace in an inert atmosphere to prepare nitrogen-doped carbon layer-coated nano silicon oxide; and adding the prepared nitrogen-doped carbon layer-coated nano silicon oxide into a dispersion liquid of a phase transfer catalyst, carrying out adsorption treatment, and then drying to obtain the supported catalyst with high specific surface area. The supported catalyst prepared by the method is large in specific surface area and high in catalytic activity, the yield and the purity of a target product are improved to a great extent when the supported catalyst is used for synthesizing paranitroaniline, the catalyst is small in dosage and convenient to recycle, and the production cost of the product is greatly improved.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a preparation method of a loaded catalyst with a high specific surface area and its application in the synthesis of p-nitroaniline. Background technique [0002] p-Nitroaniline is an extremely important intermediate in organic synthesis in the fields of dyes, pesticides, antioxidants, etc. Amines, etc., are further used in the manufacture of azo dyes, such as direct dark green B, acid medium brown G, acid black 10B, etc. [0003] At present, the domestic production method of p-nitroaniline is mainly the amination method of p-nitrochlorobenzene. p-nitrochlorobenzene and concentrated liquid ammonia are reacted in a stirred tank at 140-180°C, 3.7-5.5MPa, and a large excess of liquid ammonia for 15-20 hours, and crystallized and filtered to obtain p-nitroaniline. The process mainly has problems such as low production efficiency, unstable product quality, and poor reliability of equ...

AI Technical Summary

Problems solved by technology

This process mainly has problems such as low production efficiency, unstable product quality, and poor reliability of equipment amplification.

Some documents point out that methods such as phase transfer catalysts can be introduced to improve production efficiency. Although this method improves the yield of products to a large extent, the separation of catalysts is inconvenient and the amount of use is large, which increases the preparation cost of products.