Catalyst for selective hydrogenation of chloroaryl nitro compounds

Abstract

The present invention first provides a catalyst for catalyzing the selective hydrogenation of chlorinated aromatic nitro compounds, and the catalyst is Pt / TiO 2 / SBA‑15 catalyst or Pt / ZrO 2 / SBA-15 catalyst, and the platinum content in the catalyst is 0.01 to 0.3wt%, preferably 0.05 to 0.15wt%, and more preferably 0.08 to 0.10wt%. The present invention also provides a preparation method of the catalyst and its application in the selective hydrogenation of p-chloronitrobenzene to prepare p-chloroaniline. The catalyst in the present invention shows superior catalytic activity when used to catalyze the selective hydrogenation of p-chloronitrobenzene to prepare p-chloroaniline. The conversion rate and selectivity are very high, both can be as high as 99% or more, and dechlorination side reactions are greatly reduced. . The composite nanostructure catalyst used in the method provided by the invention has a simple preparation method, a short production cycle, a low platinum loading, and a low catalyst cost, and does not need to add a reducing agent during preparation. Platinum has good dispersion and high catalytic activity.

Description

technical field [0001] The invention belongs to the field of catalytic hydrogenation, in particular to a catalyst for catalyzing the selective hydrogenation of chlorinated aromatic nitro compounds. Background technique [0002] p-Chloroaniline is an important organic intermediate widely used in the synthesis of dyes, medicines and pesticides. At present, most p-chloroanilines are produced by reducing p-chloronitrobenzene. The reduction methods mainly include metal reduction method, electrochemical reduction method, non-hydrogen reducing agent reduction method, catalytic hydrogenation reduction method, etc., among which catalytic hydrogenation The reduction method has advanced technology and high yield, which is more in line with the requirements of modern chemical industry for atom economy; among them, the catalytic hydrogenation method of precious metals occupies the main position. In the past, the heterogeneous catalytic reduction method under high temperature and pressure...

AI Technical Summary

Problems solved by technology

However, there are always some problems in the above-mentioned prior art: as some preparation conditions are harsh in the preparation method, the reagents used are not friendly to the environment, the dispersibility of platinum is not good, and the particle size is relatively large

At present, the common methods of preparing platinum-based catalysts at home and abroad, such as impregnation method, sol-gel method, and ion exchange method, have disadvantages such as complicated preparation process, easy aggregation of platinum nanoparticles, and non-green, which affect the overall performance of the catalyst.

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