Catalyst for catalyzing selective hydrogenation of chloro nitro-compound

Abstract

The invention firstly provides a catalyst for catalyzing selective hydrogenation of a chloro nitro-compound. The catalyst is a Pt / TiO2 / SBA-15 catalyst or a Pt / ZrO2 / SBA-15 catalyst, and the content ofplatinum in the catalyst is 0.01-0.3 wt%, preferably 0.05-0.15 wt%, more preferably 0.08-0.10 wt%. The invention further correspondingly provides a preparation method of the catalyst and application of the catalyst in the reaction of selective hydrogenation of parachloronitrobenzene to prepare parachloroaniline. The catalyst shows excellent catalytic activity when used for catalyzing selective hydrogenation of parachloronitrobenzene to prepare parachloroaniline, the conversion rate and the selectivity are very high and both can reach up to 99% or above, and dechlorinating side reactions are greatly reduced. The preparation method of the composite nano-structure catalyst used in the method is simple, the production period is short, the platinum capacity is low, thus, the cost of the catalyst is low, and no reducing agent needs to be added during preparation. The dispersity of platinum is good, and catalytic activity is high.

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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