Pd-Mg/C catalyst for preparing 2,3-dichloropyridine by catalytic hydrogenation of 2,3,6-trichloropyridine and preparation method of Pd-Mg/C catalyst

A technology of catalytic hydrogenation and trichloropyridine, which is applied in the direction of catalyst activation/preparation, metal/metal oxide/metal hydroxide catalyst, physical/chemical process catalyst, etc., and can solve the problems of limited industrial application, environmental pollution, and yield Low-level problems, to achieve the effect of improving reusable performance, reducing production costs, and enhancing interaction

Active Publication Date: 2018-08-10
XIAN CATALYST NEW MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

[0003] 2,3-dichloropyridine can be obtained from 2-chloro-3-aminopyridine as a starting material through two-step reactions of diazotization and Sandmeyer chlorination. The disadvantage of this method is that the yield is low, and the raw material 2-chloropyridine The cost of -3-aminopyridine is relatively high, and diazotization produces a large amount of waste liquid, causing serious environmental pollution
2,3-dichloropyridine can also be obtained by liquid-phase chlorination of pyridine or 3-chloropyridine, but there is still the problem of low yield and no industrial application value
This method was first seen in Japanese patent JP1193246, using Pd / C as a catalyst, reacting at 50°C under normal pressure for 14 hours, the selectivity of 2,3-dichloropyridine reached 88%, but the conversion rate of raw materials was only 33%, and the production efficiency was low; in the patent CN103145609A It is reported that ammonium formate is used as the hydrogen donor, and the method of catalytic hydrogen transfer is used. Although the process is simple and the operation is safe, the yield of 2,3-dichloropyridine is only 40.83%.
[0004] At present, the catalytic hydrogenation of 2,3,6-trichloropyridine to prepare 2,3-dichloropyridine mainly has the problems of low conversion rate of raw materials and low selectivity of 2,3-dichloropyridine, which limits its industrial application

Method used

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  • Pd-Mg/C catalyst for preparing 2,3-dichloropyridine by catalytic hydrogenation of 2,3,6-trichloropyridine and preparation method of Pd-Mg/C catalyst
  • Pd-Mg/C catalyst for preparing 2,3-dichloropyridine by catalytic hydrogenation of 2,3,6-trichloropyridine and preparation method of Pd-Mg/C catalyst
  • Pd-Mg/C catalyst for preparing 2,3-dichloropyridine by catalytic hydrogenation of 2,3,6-trichloropyridine and preparation method of Pd-Mg/C catalyst

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] 1. The specific surface area of ​​10g is 1562m 2 / g of activated carbon is added to the mixed aqueous solution of 200mL hydrogen peroxide and hydrochloric acid, and the H in the mixed solution 2 o 2 The mass concentration is 10%, the HCl mass concentration is 5%, soaking at room temperature for 1 hour, then boiling for 20 minutes, washing with distilled water until neutral, and obtaining modified activated carbon.

[0019] 2. Mix 6.49g (2.82×10 -2 mol)Na 2 C 4 h 4 o 6 2H 2 Dissolve O in 200mL of distilled water, then add 9.5g of modified activated carbon, stir evenly, raise the temperature to 60°C, stir at constant temperature for 40 minutes, then add 20mL containing 1.38g Na 2 PdCl 4 (4.69×10 -3 mol) and 0.29g MgCl 2 ·6H 2 The aqueous solution of O was continuously stirred at 60°C for 2.5 hours, after standing for layers, the supernatant was poured off, and dried at 120°C.

[0020] 3. The dried sample was reduced in a hydrogen atmosphere at 200°C for 2 hour...

Embodiment 2

[0022] 1. The specific surface area of ​​10g is 1218m 2 / g of activated carbon is added to the mixed aqueous solution of 200mL hydrogen peroxide and hydrochloric acid, and the H in the mixed solution 2 o 2 The mass concentration is 5%, the HCl mass concentration is 5%, soaking at room temperature for 1 hour, then boiling for 20 minutes, washing with distilled water until neutral, and obtaining modified activated carbon.

[0023] 2. Mix 4.32g (1.88×10 -2 mol)Na 2 C 4 h 4 o 6 2H 2 Dissolve O in 200mL of distilled water, then add 9.5g of modified activated carbon, stir evenly, raise the temperature to 80°C, stir at constant temperature for 60 minutes, then add 20mL containing 1.38g Na 2 PdCl 4 (4.69×10 -3 mol) and 0.17g MgCl 2 ·6H 2 The aqueous solution of O was continuously stirred at 80°C for 3 hours, the supernatant liquid was decanted after standing for stratification, and dried at 120°C.

[0024] 3. The dried sample was reduced in a hydrogen atmosphere at 300°C f...

Embodiment 3

[0026] 1. The specific surface area of ​​10g is 1989m 2 / g of activated carbon is added to the mixed aqueous solution of 200mL hydrogen peroxide and hydrochloric acid, and the H in the mixed solution 2 o 2 The mass concentration is 15%, the HCl mass concentration is 5%, soaking at room temperature for 1 hour, then boiling for 20 minutes, washing with distilled water until neutral, and obtaining modified activated carbon.

[0027] 2. Mix 8.64g (3.75×10 -2 mol)Na 2 C 4 h 4 o 6 2H 2 Dissolve O in 200mL of distilled water, then add 9.5g of modified activated carbon, stir evenly, raise the temperature to 50°C, stir at constant temperature for 30 minutes, then add 20mL containing 1.38g Na 2 PdCl 4 (4.69×10 -3 mol) and 0.42g MgCl 2 ·6H 2 The aqueous solution of O was continuously stirred at 50°C for 2 hours, the supernatant liquid was decanted after standing for stratification, and dried at 120°C.

[0028] 3. The dried sample was reduced in a hydrogen atmosphere at 250°C ...

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Abstract

The invention discloses a Pd-Mg/C catalyst for preparing 2,3-dichloropyridine by catalytic hydrogenation of 2,3,6-trichloropyridine and a preparation method of the Pd-Mg/C catalyst. The catalyst is prepared by the following steps: mixing and stirring Na2PdCl4 and MgCl2 with activated carbon carrier treated by hydrogen peroxide and hydrochloric acid in the presence of sodium tartrate, carrying outdrying, and then carrying out reduction by using H2 to obtain the Pd-Mg/C catalyst. The preparation process of the catalyst provided by the invention realizes that nano metal is highly dispersed on the carrier, the acid-base state of the surface of the catalyst is adjusted by an auxiliary Mg, the selectivity of the 2,3-dichloropyridine is improved, meanwhile, the interaction between the noble metal palladium and the carrier is enhanced, the stability is good, the reusability of the catalyst is improved, and the production cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of preparation of supported noble metal catalysts, in particular to a Pd-Mg / C catalyst for preparing 2,3-dichloropyridine by catalytic hydrogenation of 2,3,6-trichloropyridine and a preparation method thereof. Background technique [0002] 2,3-Dichloropyridine is an important fine chemical intermediate, which is widely used in the fields of medicine and pesticide research, especially in the field of pesticides. It is an important intermediate for the synthesis of a new insecticide, chlorantraniliprole, and has a wide range of applications prospect. [0003] 2,3-dichloropyridine can be obtained from 2-chloro-3-aminopyridine as a starting material through two-step reactions of diazotization and Sandmeyer chlorination. The disadvantage of this method is that the yield is low, and the raw material 2-chloropyridine The cost of -3-aminopyridine is relatively high, and the diazotization produces a large amount of ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J23/44C07D213/61
CPCB01J23/58B01J35/0066B01J37/0207B01J37/18C07D213/61
Inventor 曾永康王昭文陈丹李岳锋曾利辉高武张之翔
Owner XIAN CATALYST NEW MATERIALS CO LTD
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