Method for preparing p-aminophenol from nitrobenzene

A technology of p-aminophenol and nitrobenzene, which is applied in the field of catalytic hydrogenation, can solve the problems of reducing the cost of catalysis, reducing poisoning, and difficulty in handling sulfuric acid, and achieves the effects of simple preparation process, accelerated reaction rate, and improved selectivity

Pending Publication Date: 2021-04-16
CHANGZHOU UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, there is still a problem of sulfuric acid corrosion in the reaction process; the invention patent CN103357407A discloses a preparation method and application of a catalyst for the preparation of p-aminophenol by a one-step method of nitrobenzene. The method is: pretreatment of activated carbon, loading of platinum salt, vanadium Loading of acid salt and reduction of catalyst; the mass percentage of platinum in the catalyst is 0.5% to 5%, and the mass percentage of vanadium is 0.05% to 2%.
By adding a certain amount of metal vanadium to the Pt/C catalyst, this invention reduces the poisoning effect of sulfide on platinum in the nitrobenzene raw material, prolongs the service life of the catalyst, and improves the catalytic activity and selectivity of the catalyst at the same time. The catalyst has stable performance and good reproducibility. It can be used to catalyze nitrobenzene to prepare p-aminophenol in one ...

Method used

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  • Method for preparing p-aminophenol from nitrobenzene
  • Method for preparing p-aminophenol from nitrobenzene
  • Method for preparing p-aminophenol from nitrobenzene

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Experimental program
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Effect test

Embodiment 1

[0023] In the first step, weigh 1 g of HZSM-5 molecular sieve and put it into a muffle furnace, and bake it at 500°C for 6 hours. Then soak in dilute sulfuric acid (0.5 mol / ml, mass ratio to carrier: 1:10, the same below) for 1 hour, dry it and put it into a muffle furnace for calcination at 400°C for 5 hours.

[0024] The second step, weigh 0.1397gH 2 PtCl 6 ·6H 2 O (equivalent to metal Pt is 0.05263g), dissolved in water to prepare an impregnating solution, using the equal volume impregnation method to use 1g of the HZSM-5 molecular sieve treated in step 1 as a carrier and soaking in the impregnating solution for half an hour.

[0025] In the third step, put the material impregnated in the second step into an oven and dry at 100°C.

[0026] In the fourth step, the material obtained in the third step is put into a muffle furnace and fired at 500° C. for 3 hours.

[0027] In the fifth step, put the burned material in the fourth step into a tube furnace at 500° C. for hydro...

Embodiment 2

[0030] Step is with embodiment 1.

[0031] Carrier is HZSM-5 molecular sieve (silicon to aluminum ratio 45) in this catalyst, and the loading capacity of metal Pt is 5%

Embodiment 3

[0033] In the first step, weigh 1 g of HZSM-5 molecular sieve and put it into a muffle furnace, and bake it at 700°C for 4 hours. After soaking in dilute sulfuric acid for 1 hour, put it into a muffle furnace and bake at 300°C for 6 hours.

[0034] The second step, weigh 0.1106gH 2 PtCl 6 ·6H 2 O (equivalent to metal Pt is 0.04167g), dissolved in water to prepare an impregnating solution, and 1 g of HZSM-5 molecular sieve as a carrier was placed in the impregnating solution for half an hour by equal volume impregnation method.

[0035] In the third step, put the material impregnated in the second step into an oven and dry at 100°C.

[0036] In the fourth step, put the material obtained in the third step into a muffle furnace and burn it at 600° C. for 2 hours.

[0037] In the fifth step, put the burnt material in the fourth step into a tube furnace at 600° C. for hydrogen reduction for 3 hours to obtain a catalyst for preparing p-aminophenol from nitrobenzene.

[0038] Carr...

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PUM

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Abstract

The invention discloses a method for preparing p-aminophenol from nitrobenzene, which mainly comprises the following steps: carrying out hydrogen reduction reaction in a CO2/H2O system in a high-pressure reaction kettle at 100-150 DEG C for 4-7 hours by using Pt as a main active component and Mg, Cr and Ni as assistants under the conditions that the H2 pressure is 0.5-2 MPa and the CO2 pressure is 4-6 MPa; after the reaction is finished, filtering the catalyst out and drying the same for continuous use, wherein the selectivity of the p-aminophenol can reach 85% or above. According to the reaction, a CO2/H2O system is used for replacing a traditional sulfuric acid system, the problems of sulfuric acid pollution to the environment and aftertreatment are solved, meanwhile, the problem of corrosion of sulfuric acid to equipment is avoided, the catalyst with the HZSM-5 molecular sieve as the carrier can adjust the acidity of the carrier, meanwhile, the defect that the acidity of the CO2/H2O system is insufficient is overcome, and the stability of the catalyst is good.

Description

technical field [0001] The invention belongs to the field of catalytic hydrogenation and relates to a method for preparing p-aminophenol from nitrobenzene. Background technique [0002] p-Aminophenol (p~Aminophenol, referred to as PAP), is an important organic intermediate and chemical raw material, widely used in medicine, rubber, dyes and other industries. In the pharmaceutical industry, p-aminophenol is mainly used in the production of paracetamol and other drugs. Paracetamidyl acetylsalicylate), vitamins, compound nicotinamide, clofibrate, 6-hydroxyquinoline, salaminophen, etc., are very important pharmaceutical intermediates; in the dye industry, PAP can be used as As an intermediate of dyes, p-aminophenol can also be used in the dye industry to produce various dyes such as dispersants, acid dyes, direct dyes, sulfur dyes and fur dyes; in the rubber industry, PAP is mainly used to produce p-phenylenediamine Anti-aging agent, with non-toxic, low pollution, high efficie...

Claims

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Application Information

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IPC IPC(8): B01J29/58B01J37/08B01J37/02B01J37/18C07C215/76C07C213/00
Inventor 何明阳张宇钱俊峰孙中华吴中
Owner CHANGZHOU UNIV
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