Preparation method and application of catalyst for one-step preparation of p-aminophenol from nitrobenzene

A technology of p-aminophenol and nitrobenzene, which is applied in the field of preparation of catalysts for the preparation of p-aminophenol by one-step method of nitrobenzene, can solve the problems of relatively large impact on catalyst life, reduced catalyst service life, poor PAP selectivity, etc., and achieves strong Anti-sulfur poisoning performance, reduced catalytic cost, and stable performance

Inactive Publication Date: 2013-10-23
XIAN CATALYST NEW MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For example Chinese patent CN85103667A, the used catalyzer of the synthetic method of the p-aminophenol disclosed by CN1087263A is Pt / carbon catalyst, lauryltrimethylammonium chloride is tensio-active agent, and selectivity is good, but this kind of catalyzer active carbon The pores are thin and deep, the product is easy to block the inner pores and deactivate the catalyst, and the metal is also easy to lose, which has a great impact on the life of the catalyst
U.S. Patent No. 4,885,389 and US No. 4,264,529 disclose p-aminophenol synthesis methods using Pt / C or Pt / alumina, wherein the Pt / alumina catalyst is easily dissolved in the presence of an acidic medium, and the catalyst loss is serious
The p-aminophenol synthesis method disclosed in Chinese patent CN1075489C uses a Pt / nylon catalyst, which has good catalyst stability, but has the defect of poor PAP selectivity
The Pt / C catalyst disclosed in U.S. Patent No. 4,571,437 adds sulfides such as ethyl sulfide and dimethyl sulfoxide during use to improve the selectivity of the catalyst, but reduces the service life of the catalyst

Method used

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  • Preparation method and application of catalyst for one-step preparation of p-aminophenol from nitrobenzene
  • Preparation method and application of catalyst for one-step preparation of p-aminophenol from nitrobenzene

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Embodiment 1

[0027] Step 1, pretreatment of activated carbon: add 20g of powdered activated carbon to 150mL of nitric acid solution with a mass concentration of 4%, boil for 2 hours, filter after cooling; then wash the filtered solid with deionized water until the pH value is 7; The washed solid was added to 150 mL of 8% hydrochloric acid solution and boiled for 0.8 h, filtered after cooling, and the filtered solid was washed with deionized water until neutral to obtain pretreated activated carbon;

[0028] Step 2. Platinum salt loading: Add 19.56 g of the pretreated activated carbon described in step 1 into 390 mL of deionized water, and heat to 80° C. under stirring conditions to disperse the pretreated activated carbon in the deionized water evenly to obtain a carbon slurry; Then, under stirring conditions, slowly dropwise add a platinum chloride aqueous solution having a platinum content of 0.4 g and a concentration of 0.01 g / mL to the carbon slurry, and then keep stirring for 1 h after...

Embodiment 2

[0032]Step 1, pretreatment of activated carbon: add 20g of powdered activated carbon to 200mL of nitric acid solution with a mass concentration of 5%, boil for 1h, filter after cooling; then wash the filtered solid with deionized water until the pH value is 5; The washed solid was added to 200 mL of 5% hydrochloric acid solution and boiled for 1 h, filtered after cooling, and the filtered solid was washed with deionized water until neutral to obtain pretreated activated carbon;

[0033] Step 2. Platinum salt loading: Add 18.6 g of the pretreated activated carbon described in step 1 into 370 mL of deionized water, and heat to 90° C. under stirring conditions to disperse the pretreated activated carbon in the deionized water evenly to obtain a carbon slurry; Then, slowly dropwise adding platinum nitrate aqueous solution of 0.02 g / mL with a platinum content of 1 g to the carbon slurry under stirring conditions, after the dropwise addition, it was incubated and stirred for 2 hours ...

Embodiment 3

[0037] Step 1. Pretreatment of activated carbon: add 20 g of powdered activated carbon to 100 mL of 3% nitric acid solution and boil for 3 hours, filter after cooling; then wash the filtered solid with deionized water until the pH value is 6; The washed solid was added to 100 mL of 10% hydrochloric acid solution and boiled for 0.5 h, filtered after cooling, and the filtered solid was washed with deionized water until neutral to obtain pretreated activated carbon;

[0038] Step 2. Platinum salt loading: Add 19.2 g of the pretreated activated carbon described in step 1 into 100 mL of deionized water, and heat to 85° C. under stirring conditions to disperse the pretreated activated carbon in the deionized water evenly to obtain a carbon slurry; Then, under stirring conditions, slowly dropwise add a platinum acetate solution with a platinum content of 0.6 g and a concentration of 0.001 g / mL in the carbon slurry, and then insulate and stir for 0.5 h after the dropwise addition, to o...

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Abstract

The invention discloses a preparation method of a catalyst for the one-step preparation of p-aminophenol from nitrobenzene. The method comprises the following steps: preprocessing active carbon; loading a platinum salt; loading a vanadate; and reducing a catalyst, wherein the mass percentage contents of platinum and vanadium in the catalyst are 0.5-5% and 0.05-0.2% respectively. The invention also discloses a method for the one-step preparation of p-aminophenol from nitrobenzene through utilizing the catalyst. The addition of a certain amount of metallic vanadium to the Pt/C catalyst reduces the poisoning effect of sulfides in the nitrobenzene raw material to platinum, prolongs the service life of the catalyst and also improves the catalysis activity and selectivity of the catalyst; and the prepared catalyst has stable performances and very good repeatability, can be used for catalyzing the one-step preparation of p-aminophenol from nitrobenzene, reduces the purity requirement of the raw material nitrobenzene and reduces the catalysis cost.

Description

technical field [0001] The invention belongs to the technical field of preparation of precious metal catalysts, and in particular relates to a preparation method and application of a catalyst for preparing p-aminophenol by one-step method of nitrobenzene. Background technique [0002] p-Aminophenol is a widely used organic intermediate. It is mainly used in the production of paracetamol, dyes, rubber anti-aging agents and photographic developers, antioxidants and petroleum additives, etc., and has a wide range of uses. There are many ways to prepare p-aminophenol, mainly including: (1) metal reduction, catalytic hydrogenation and electrolytic reduction of p-nitrophenol; (2) nitrosation, coupling and halogenation of phenol; (3) ammonification of hydroquinone ; (4) Nitrobenzene metal reduction, electrolysis and catalytic hydrogenation. Among the many production methods of p-aminophenol, the catalytic hydrogenation of nitrobenzene has cheap and easy-to-obtain raw materials, l...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J23/648C07C215/76C07C213/00
Inventor 李钊姚琪朱柏烨曾永康张之翔
Owner XIAN CATALYST NEW MATERIALS CO LTD
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