Catalyst for liquid phase hydrogenation of chloronitrobenzene and preparation method thereof

Abstract

The invention discloses a catalyst for liquid phase hydrogenation of chloronitrobenzene and a preparation method thereof. The invention is characterized in that the catalyst consists of amorphous alloy NiB, wherein the mass percentage of Ni is 10 to 80 percent and the mass percentage of B is 20 to 90 percent. The preparation method is an ultrasonic wave-assisted liquid phase reduction method, and comprises the following steps: (1) preparing solution; (2) forming a precipitate; and (3) washing precipitate and storing. The invention has the advantages that: the catalyst has high activity and selectivity; and when the catalyst is used, the chloronitrobenzene conversion rate is over 99 percent and the dechloridation rate is below 4 percent.

Description

(1) Technical field: [0001] The invention relates to a catalyst, in particular to a catalyst for liquid-phase hydrogenation of chloronitrobenzene and a preparation method thereof. (two) background technology: [0002] Chlorinated organic compounds are products in which one or several hydrogen atoms in aliphatic hydrocarbons, aromatic hydrocarbons and their derivatives are replaced by chlorine atoms. A variety of chlorinated hydrocarbons are used as basic raw materials or intermediates for various organic synthesis, and are widely used in industries such as organic chemicals, pesticides, medicines, dyes, etc., thus making the production of chlorinated hydrocarbons very important in the organic chemical industry. Part. [0003] However, the production process of chlorinated aromatic amines is relatively backward. At present, iron powder and alkali sulfide reduction methods are mainly used in China. Such a process will produce dozens of tons of high-concentration, difficult-to...

AI Technical Summary

Problems solved by technology

[0003] However, the production process of chlorinated aromatic amines is relatively backward. At present, iron powder and alkali sulfide reduction methods are mainly used in China. Such a process will produce dozens of tons of high-concentration, difficult-to-treat organic sewage and toxic Sludge, a variety of chlorinated organic compounds can pose serious threats to the environment and ecosystem

[0004] Commonly used catalysts include Raney Ni and supported noble metals (such as Pd / C and Pt / Al2O3, etc.), but this method has the disadvantage of hydrogenolysis and dehalogenation. There are two main methods to prevent hydrogenolysis and dehalogenation. One is to add dehalogenation inhibitors or The hydrogenation catalyst is pre-poisoned, but the addition of dehalogenation inhibitors will increase secondary pollution, bring difficulties to separation and increase production costs, while poisoning the hydrogenation catalyst will greatly reduce the activity of the catalyst; the second is to improve the performance of the catalyst, However, in most cases, the activity and stability of the treated hydrogenation catalyst will decrease, resulting in an increase in the amount of catalyst used. Therefore, the problem of dehalogenation has not been well solved by greening.