Catalyst for liquid-phase hydrogenation reduction reaction of 6-chloro-3-nitrotoluene-4-sulfonic acid (CLT acid) and method for preparing same

A technology of nitrotoluene and sulfonic acid solution, applied in the preparation of sulfonic acid, metal/metal oxide/metal hydroxide catalyst, chemical instruments and methods, etc., can solve the problem of low reduction yield, environmental pollution and low product purity and other problems, to achieve the effect of improving catalytic activity, reducing in-depth reactions, and reducing environmental pollution

Active Publication Date: 2012-10-03
NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] The technical purpose of the present invention is aimed at the process of producing CLT acid with toluene sulfonation route, when adopting iron powder etc. as catalyst reduction 6-chloro-3 nitrotoluene-4-sulfonic acid, the reduction yield produced is low, the product In order to solve the problems of low purity and serious environmental pollution, a new catalyst for the liquid-phase hydrogenation reduction reaction of 6-chloro-3-nitrotoluene-4-sulfonic acid in the production process of CLT acid is provided. The catalyst has good hydrogenation activity , high selectivity, low dechlorination advantages, high reduction rate, good product purity and less environmental pollution when using this catalyst to reduce 6-chloro-3 nitrotoluene-4-sulfonic acid

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] In this example, the catalyst used for the liquid-phase hydrogenation reduction reaction of 6-chloro-3-nitrotoluene-4-sulfonic acid is supported by Raschig ring type (that is, single-hole cylindrical) alumina, and on its surface The active component Pd is loaded, and the active component Pd is distributed in an eggshell shape on the surface of Raschig ring alumina. The specific preparation process of the catalyst is as follows.

[0036] (1) Take 0.098 moles of Raschig ring-type alumina and calcinate it at 300°C for 2 hours, and then cool it to room temperature. The purity of Raschig ring-type alumina is 99.5%, and the specific surface area is 103 m 2 / g, the pore volume is 0.5 ml / g carrier;

[0037] (2) Mix the Raschig ring-type alumina treated in step (1) with 4 ml of chloropalladium acid solution (containing 4 mg of elemental palladium), dissolve it in water, and then add 10 ml of aqueous sodium hydroxide solution (containing 0.0078 sodium hydroxide mol), impregnate...

Embodiment 2

[0044] In this example, the catalyst used for the liquid-phase hydrogenation reduction reaction of 6-chloro-3-nitrotoluene-4-sulfonic acid is supported by Raschig ring-type alumina, and the active component Pd is loaded on its surface, and The active component Pd is distributed in an eggshell shape on the surface of Raschig ring-type alumina, and the carrier is also loaded with additive K 2 O. The specific preparation process of the catalyst is as follows.

[0045] (1) Exactly the same as step (1) in Example 1;

[0046] (2) Exactly the same as step (2) in Example 1;

[0047] (3) Add 0.5 ml of K to the reaction product obtained in step (2) 2 CO 3 , and then reduced in 50 milliliters of 2% hydrazine hydrate aqueous solution for 1 hour; finally washed and dried to obtain the finished catalyst, wherein the active component Pd mass accounts for 0.2% of the Raschig ring-type alumina mass, K 2 The mass of O accounts for 0.05% of the mass of Raschig ring alumina.

[0048] The ca...

Embodiment 3

[0051] In this example, the structure of the catalyst used for the liquid-phase hydrogenation reduction reaction of 6-chloro-3-nitrotoluene-4-sulfonic acid is exactly the same as that in Example 2. The specific preparation process of the catalyst is as follows.

[0052] (1) It is basically the same as step (1) in Example 2, except that the Raschig ring alumina is calcined at 500°C for 2 hours;

[0053] (2) exactly the same as step (2) in Example 2;

[0054] (3) exactly the same as step (3) in Example 2;

[0055] Obtain the finished catalyst, wherein the active component Pd quality accounts for 0.2% of the Raschig ring type alumina quality, K 2 The mass of O accounts for 0.05% of the mass of Raschig ring alumina.

[0056] The catalyst prepared above was used in the continuous hydrogenation reduction of 6-chloro-3-nitrotoluene-4-sulfonic acid to prepare CLT acid. The specific preparation process was the same as the preparation process of CLT acid in the above-mentioned Exampl...

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Abstract

The invention provides a catalyst for the liquid-phase hydrogenation reduction reaction of 6-chloro-3-nitrotoluene-4-sulfonic acid (CLT acid) and a method for preparing the catalyst. The alumina (Al2O3) in the columnar structure or spherical structure is used as the carrier, and the active component which is the palladium (Pd) is supported on the surface of the carrier so that the Pd / Al2O3 catalyst preferentially distributed like an eggshell is formed, wherein the mass of the platinum is 0.05-10% of that of the carrier. Compared with the prior art, the catalyst provided by the invention has good hydrogenation activity, high selectivity and low dechlorination. When the catalyst is used for the hydrogenation reduction and the production of the CLT acid, high reduction rate is achieved, the product has good purity, and less pollution is caused to the environment.

Description

technical field [0001] The invention relates to the technical field of CLT acid, in particular to a catalyst for liquid-phase hydrogenation reduction reaction of 6-chloro-3-nitrotoluene-4-sulfonic acid and a preparation method thereof. Background technique [0002] 6-chloro-3-aminotoluene-4-sulfonic acid, its English name is 6-chloro-3-nitrotoluene-4-sulfonic acid, referred to as CLT acid. CLT acid is an important red organic pigment intermediate. It is mainly used in the production of C.I. Pigment Red 52 and C.I. Pigment Red 53 in the pigment industry. The pigment is widely used in paints, coatings, color inks, rubber and plastic coloring, etc. [0003] There are many synthetic routes of CLT acid, which mainly include: [0004] (1) Toluene sulfonation route: This route has the advantages of rich and easy-to-obtain raw materials, mature technology, and low cost; The three wastes in the process are large and difficult to handle; [0005] (2) The bromination route of o-chlo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J23/44C07C309/48C07C303/22
Inventor 周生虎徐乐
Owner NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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