CN1762588A - Supported nickel catalyst for synthesizing chlora aniline by hydrogenation of chloronitrobenzene and its preparation method thereof - Google Patents

Abstract

The invention relates to a carrier nickel-base catalyst used to hydrogenate the chloronitrobenzene to synthesize chloroaniline, which comprises silicon dioxide, titania or zirconia as carrier, wherein 10~40% nickel. The preparation process comprises: drying, dipping, calcining, reducing, and activating. The advantages of this invention include: low cost, simple process, little pollution, and well reaction performance.

Description

Nickel catalyst carried and the preparation method of hydrogenating chloronitrobenzene to synthesize chloroaniline

Technical field

The present invention relates to the nickel catalyst carried and preparation method thereof of the synthetic chloro aminobenzen of a kind of chloronitrobenzene liquid-phase hydrogenatin, belong to the catalyst technology that is used for the synthetic chloro aminobenzen of chloronitrobenzene liquid-phase hydrogenatin.

Background technology

Chloro aminobenzen is the important organic intermediate of a class, is widely used in the synthetic of fine chemical products such as medicine, dyestuff, pigment.For example, o-chloraniline can be applicable to the dyestuff color base, as diazo component and the manufacturing medicine and the pesticide intermediate of azo dyes.

At present, industrial main employing iron powder reducing, akali sulphide or hydrazine hydrate reduction, sulfonation ammonia is separated with several method such as liquid phase catalytic hydrogenation by the synthetic chloro aminobenzen of nitro-chlorobenzene.Wherein, adopt the reduction reaction route of iron powder, akali sulphide or hydrazine hydrate etc. that long flow path is arranged, the three wastes are many, poor product quality, fatal shortcoming such as severe operational environment.Adopt the sulfonation ammonolysis process then need add mercury salt location agent, also be easy to cause environmental pollution.Comparatively speaking, the catalytic hydrogenating reduction method is the green production process that comparatively cleans, and has the application prospect of good sustainable development.

In chloronitrobenzene liquid phase catalytic hydrogenation course of reaction, not only to guarantee higher reaction-ure conversion-age, and to suppress to encircle the generation of side reaction such as dechlorination, and keeping high target product selectivity, one of key factor wherein is the catalyst that design, preparation have suitable hydrogenation performance.At present, study and use more liquid phase hydrogenating catalyst and comprise: with inorganic carrier or carrier loaded noble metal catalyst (Appl Catal, 1997,164:197～203 of macromolecular compound; J Mol Catal, 2000,159:115～120; J Colloid Interface Sci, 1999,214:231～237; J Mol Catal, 1991,68 (3): 331～345; J Mol Catal, 2004,209:83～87 etc.), skeletal nickel catalyst (dye industry, 1997,34 (5): 31～33; Petrochemical industry, 2002,31 (1): 6～9; US 6 034 276 etc.) and amorphous alloy catalyst (catalysis journal, 2004,25 (5): 369～372; The catalysis journal, 2005,26 (3): 233～237; Deng).Noble metal catalyst catalytic activity height, selectivity is good, and reaction condition gentleness, its shortcoming are the cost height.Though Raney's nickel catalyst has the lower advantage of price, the side reaction of its hydrogenation-dechlorination is comparatively serious, needs to adopt the co-catalyst with toxicity to improve product selectivity; Simultaneously, Raney's nickel catalyst also still exists pollution and safety issue in preparation and use.Amorphous alloy is as a kind of new catalytic material, and its heat endurance is still waiting further raising.

Summary of the invention

The object of the present invention is to provide the nickel catalyst carried and preparation method of a kind of hydrogenating chloronitrobenzene to synthesize chloroaniline, this catalyst reaction performance is good, and preparation technology is simple.

The present invention is realized that by following technical proposals a kind of hydrogenating chloronitrobenzene to synthesize chloroaniline is nickel catalyst carried, it is characterized in that, and be carrier with zirconia, titanium dioxide or silica, the mass content of nickel is 10～40%.

Above-mentioned Preparation of catalysts method is characterized in that, comprises the following steps:

1) with zirconia, titanium dioxide or silica supports 100～120 ℃ of dryings 1～4 hour;

2) carrier impregnation with drying is in the solution of 15～50% nickel nitrates or nickel chloride in mass concentration, flooded 2～6 hours down in 20～30 ℃, the carrier that resulting load is had an active component through 100～140 ℃ dry after after 2～6 hours, in air in 400～700 ℃ of following roastings 2～6 hours;

3) catalyst that roasting is prepared hydrogen content be in hydrogen-nitrogen mixture of 10～30% in 400～600 ℃ of reduction 1～4 hour, promptly prepare loading type nickel-based catalyst involved in the present invention.

Characteristics of the present invention are that prepared catalyst cost is lower, and preparation technology is simple, pollute for a short time, and have the reactivity worth of good hydrogenating chloronitrobenzene to synthesize chloroaniline, and the dechlorination performance is low.

The specific embodiment

Embodiment 1

With titanium dioxide 110 ℃ of dryings 4 hours, adopt equi-volume impregnating with nickel nitrate aqueous solution in 30 ℃ of dippings 4 hours, then 110 ℃ dry 4 hours down, again in air atmosphere in 400 ℃ of roastings 2 hours.Then, it is 10% catalyst that this catalyst precursor down promptly gets nickel content with hydrogen reducing 2h at 400 ℃, under protection of nitrogen gas it is joined in the ethanolic solution that is dissolved with o-chloronitrobenzene.Be dissolved at 80 ℃, hydrogen pressure 1.0MPa, catalyst amount 500mg, MDNB 5g under the condition of 100ml ethanol and react, behind the reaction 60min, the o-chloronitrobenzene conversion ratio is 99.9%, and the selectivity of o-chloraniline is 99.1%.

Embodiment 2

Catalyst preparation process and catalytic hydrogenation reaction condition are with embodiment 1, and difference is a catalyst carrier for adopting zirconia.Behind the reaction 200min, the o-chloronitrobenzene conversion ratio is 99.5%, and the selectivity of o-chloraniline is 98.1%.

Embodiment 3

Catalyst preparation process and catalytic hydrogenation reaction condition are with embodiment 1, and difference is a catalyst carrier for adopting silica.Behind the reaction 600min, the o-chloronitrobenzene conversion ratio is 80.5%, and the selectivity of o-chloraniline is 96.6%.

Embodiment 4

Catalyst preparation process and catalytic hydrogenation reaction condition are with embodiment 1, and difference is that nickel content is 40% in the catalyst.Behind the reaction 50min, the o-chloronitrobenzene conversion ratio is 99.9%, and the selectivity of o-chloraniline is 99.3%.

Embodiment 5

Catalyst preparation process and catalytic hydrogenation reaction condition are with embodiment 1, and difference is that the temperature of catalyst roasting in air atmosphere is 500 ℃.Behind the reaction 40min, the o-chloronitrobenzene conversion ratio is 99%, and the selectivity of o-chloraniline is 99.5%.

Embodiment 6

Catalyst preparation process and catalytic hydrogenation reaction condition are with embodiment 1, and difference is that the reduction temperature of catalyst is 600 ℃.Behind the reaction 70min, the o-chloronitrobenzene conversion ratio is 99%, and the selectivity of o-chloraniline is 99%.

Embodiment 7

Catalyst preparation process and catalytic hydrogenation reaction condition are with embodiment 1, and difference is a reactant for adopting parachloronitrobenzene.Behind the reaction 53min, the parachloronitrobenzene conversion ratio is 99%, and the selectivity of parachloroanilinum is 99.5%.

Embodiment 8

Catalyst preparation process and catalytic hydrogenation reaction condition are with embodiment 1, and difference is for adopting 2, and the 5-dichloronitrobenzene is a reactant.Behind the reaction 70min, 2,5-dichloronitrobenzene conversion ratio is 98%, 2, the selectivity of 5-dichloroaniline is 98.5%.

Claims (2)

1. a hydrogenating chloronitrobenzene to synthesize chloroaniline is nickel catalyst carried, it is characterized in that, and be carrier with zirconia, titanium dioxide or silica, the load quality content of nickel is 10～40%.

2. a method for preparing the described catalyst of claim 1 is characterized in that, comprises the following steps:

1) with zirconia, titanium dioxide or silica supports 100～120 ℃ of dryings 1～4 hour;

2) carrier impregnation with drying is in the solution of 15～50% nickel nitrates or nickel chloride in mass concentration, flooded 2～6 hours down in 20～30 ℃, the carrier that resulting load is had an active component through 100～140 ℃ dry after after 2～6 hours, in air in 400～700 ℃ of following roastings 2～6 hours;

3) catalyst that roasting is prepared hydrogen content be in hydrogen-nitrogen mixture of 10～30% in 400～600 ℃ of reduction 1～4 hour, obtain being used for the loading type nickel-based catalyst of hydrogenating chloronitrobenzene to synthesize chloroaniline.