CN102728386A

CN102728386A - Pd-Ni/Al2O3 catalyst, its preparation method and application thereof

Info

Publication number: CN102728386A
Application number: CN2012102104171A
Authority: CN
Inventors: 冯乙巳; 程月; 郑波; 周雪梅; 许皓诚; 王维丞
Original assignee: Hefei University of Technology
Current assignee: Hefei University of Technology
Priority date: 2012-06-25
Filing date: 2012-06-25
Publication date: 2012-10-17
Anticipated expiration: 2032-06-25
Also published as: CN102728386B

Abstract

The invention discloses a Pd-Ni/Al2O3 catalyst, its preparation method and an application thereof. With PdCl2 and Ni(NO3)2 being used as active components and Al2O3.H2O being used as a catalyst carrier, the Pd-Ni/Al2O3 catalyst is prepared by loading the active components onto the catalyst carrier, wherein the gross mass of PdCl2 and Ni(NO3)2 is 0.5-1 wt% of the weight of Al2O3.H2O and the mass ratio of Pd to Ni in the active components is 1:0.5-3. The Pd-Ni/Al2O3 catalyst can be used as a selective catalyst in cyclopentadiene selective hydrogenation for synthesis of cyclopentene. By the adoption of the catalyst, hydrogenation reaction can be conducted at normal temperature; the reaction condition is mild; conversion rate and selectivity are very good; the conversion rate is 98-99.5%; and the selectivity of cyclopentene also reaches 97-98.5%.

Description

A kind of Pd-Ni/Al 2O 3Catalysts and its preparation method and purposes

One, technical field

The present invention relates to a kind of Pd-Ni/Al ₂O ₃Catalysts and its preparation method and purposes prepare in the cyclopentene at the cyclopentadiene catalytic hydrogenation and to use as catalyst.

Two, background technology

In recent years, along with the fast development of ethylene industry, the output of C 5 fraction sharply rises, and dicyclopentadiene accounts for 21% of C 5 fraction, makes dicyclopentadiene have very much researching value as the raw material of synthetic cyclopentene.The dicyclopentadiene cut generates cyclopentadiene through depolymerization, and selective hydrogenation can obtain cyclopentene then.In the dicyclopentadiene downstream product; Cyclopentene occupies very important position; Because cyclopentene specific structure; It is a kind of important Organic Chemicals, can be used for preparing high added value intermediates such as cyclopentanol, cyclopentanone, glutaraldehyde, ring amyl methyl ether, bromocyclopentane, is widely used in fields such as spices, medical industry and synthetic rubber.

The key of cyclopentadiene hydrogenating is activity of such catalysts and selectivity thereof, has the report of multiple hydrogenation catalyst abroad, but all there are shortcomings such as preparation complicacy, life-span weak point, poor selectivity in these catalyst.Cyclopentadiene can selective hydrogenation under appropriate condition generates cyclopentene, and also hydrogenation generates pentamethylene entirely, and this depends primarily on the condition of reacting employed catalyst and reaction etc.Because cyclopentene and pentamethylene boiling point are comparatively approaching, be difficult to separate, the productive rate of therefore selecting proper reaction conditions and hydrogenation catalyst to improve target product is a critical problem.In the early stage bibliographical information; The selection hydrogenation catalyst that is prepared cyclopentene by cyclopentadiene hydrogenating more typically has Raney nickel, and the use Raney nickel of mentioning like U.S. Pat 4108911 is as catalyst, and ethylene glycol is as solvent; Under certain condition, the conversion ratio of cyclopentadiene reaches 90.7%.The selectivity of cyclopentene is 96.7%.Bibliographical information is also arranged in the recent period, Pd salt as the major catalyst effect under, be raw material with the cyclopentadiene, ethanol is as solvent, catalytic hydrogenation reaction has synthesized cyclopentene; Investigated the influence of the existence of different anions Pd salt in the catalyst system and catalyzing and multiple co-catalyst to selective hydrogenation.But their catalyst is difficult with separating of cyclopentene, and the conversion ratio of cyclopentadiene is lower, because the boiling point of cyclopentadiene and cyclopentene are very approaching, the purification of product will be compared difficulty like this.It is main active component with the Metal Palladium that employing is also arranged in the prior art, Al ₂O ₃, active carbon etc. is used for the reaction that cyclopentadiene is selected the hydrogenation preparing cyclopentene as the solid supported of carrier, this solid catalyst can separate with product more easily.As reporting with γ-Al among the Chinese patent CN1911877A ₂O ₃Be carrier; Metal Palladium is an active component, and solvent is taken from any in toluene, the cyclohexane etc., through being employed in the heat-exchanger rig of settling a kind of injector in the hydrogenation reactor; The comparatively ideal reaction heat of having removed the generation of cyclopentadiene hydrogenating process; Make reaction obtain higher cyclopentene yield, but this method complicated operation, and cost is higher.To have proposed a kind of active component be Pd-Zn to Deutsche Bundespatent for another example, and carrier is Al ₂O ₃Loaded catalyst be used for the cyclopentadiene hydrogenating preparing cyclopentene.Though this scheme cyclopentene selectivity can reach 96%, the cyclopentadiene conversion ratio is merely 86%.

Three, summary of the invention

The present invention is intended to for the synthetic cyclopentene of cyclopentadiene selective hydrogenation provides a kind of catalysts selective, with the selectivity of raising reaction and the conversion ratio of product.

The catalyst that the present invention uses is easy to separate with product; Reuse is preferably arranged; The use of mixed solvent has also effectively reduced a large amount of heats that produce in the course of reaction, and reaction condition is also relatively gentleer simultaneously, can solve some defectives of prior art scheme effectively.

Pd-Ni/Al of the present invention ₂O ₃Catalyst is characterized in that: with PdCl ₂And Ni (NO ₃) ₂Be active component, with Al ₂O ₃H ₂O is a catalyst carrier, the catalyst that obtains after being carried on active component on the catalyst carrier;

PdCl ₂And Ni (NO ₃) ₂Gross mass be Al ₂O ₃H ₂The 0.5-1% of O quality;

The mass ratio of Pd and Ni is 1:0.5-3 in the active component.

Pd-Ni/Al of the present invention ₂O ₃The Preparation of catalysts method comprises each unit process of load and activation:

Said load is with PdCl ₂And Ni (NO ₃) ₂Be dissolved in the acetum of mass concentration 25-35%, add Al after the stirring and dissolving again ₂O ₃H ₂O stirs and leaves standstill 1.5-2.5h, subsequently in 100-120 ℃ of dry 8-10h, again in 540-560 ℃ of roasting 2.5-3.5h; PdCl ₂And Ni (NO ₃) ₂Gross mass be Al ₂O ₃H ₂The 0.5-1% of O quality, Pd and Ni mass ratio are 1:0.5-3;

Said activation is to feed hydrogen after the roasting to carry out catalyst activation, activation temperature 240-260 ℃, and activation pressure 0.1-0.2MPa, hydrogen flowing quantity 40-50ml/min soak time 40-50 hour, promptly makes Pd-Ni/Al ₂O ₃Catalyst.

Pd-Ni/Al of the present invention ₂O ₃The purposes of catalyst is characterized in that: prepare in the cyclopentene as Application of Catalyst in cyclopentadiene liquid phase catalytic hydrogenation reduction reaction.

The detailed process that the cyclopentadiene catalytic hydrogenation prepares cyclopentene is following:

With the cyclopentadiene is raw material, is mixed solvent with ethanol and acetonitrile, in hydrogen atmosphere, Pd-Ni/Al ₂O ₃In 25-40 ℃ of reaction 1.5-3 hour, Hydrogen Vapor Pressure was controlled at 0.8-1.5MPa, Pd-Ni/Al under the existence of catalyst ₂O ₃The addition of catalyst is the 3-7% of cyclopentadiene quality; The volume ratio of ethanol and acetonitrile is 1:0.2-1 in the mixed solvent; The addition of mixed solvent is 5-10 a times of cyclopentadiene quality.

Utilize the reaction scheme of catalyst to catalyzing hydrogenating of the present invention following:

The present invention selects the bimetallic catalyst of Pd and Ni, and the adding of Ni active component reduces activity of such catalysts, suppressed the cyclopentadiene excessive hydrogenation and generated pentamethylene, thereby the synthetic cyclopentene of cyclopentadiene selective hydrogenation has better choice property.Pd salt is much lower because the cost of Ni salt is compared, and the Ni catalyst also reduces reaction cost as the adding of co-catalyst.

The present invention is with Al ₂O ₃H ₂O under the same conditions, uses Al as catalyst carrier ₂O ₃H ₂O is as catalyst carrier and γ-Al ₂O ₃Compare as carrier, the output of cyclopentene can improve 10-20%, and this is because the former has a large amount of constitution waters, and there is a large amount of hydrophilic hydroxyls in the surface of catalyst, improved the selectivity of its catalysis greatly.

The cyclopentadiene hydrogenating reaction is a strong exothermal reaction; In order to reduce the thermal discharge of reaction; The present invention selects ethanol and acetonitrile mixed solvent, and the use of mixed solvent has increased the selectivity of cyclopentene, and can effectively stop in the course of reaction Yin Wendu too high; The cyclopentadiene self-polymerization generates dicyclopentadiene, and the application of mixed solvent simultaneously makes activity of such catalysts obtain prolonging.

Use catalyst hydrogenation reaction of the present invention to carry out at normal temperatures; Reaction condition is gentle; Employed load property catalyst is easy to separate with product; And the synthetic cyclopentene of cyclopentadiene selective hydrogenation has extraordinary conversion ratio and selectivity, and conversion ratio is 98-99.5%, and the selectivity of cyclopentene also reaches 97-98.5%.

Conversion ratio of the present invention and optionally computational methods are following:

Four, the specific embodiment

Non-limiting examples of the present invention is narrated as follows:

1, Preparation of catalysts

With PdCl ₂And Ni (NO ₃) ₂Add in the acetum of mass concentration 30%, Pd and Ni mass ratio are 1:0.5-3, add Al after the stirring and dissolving again ₂O ₃H2O; Stir and leave standstill 2h, subsequently in 100-120 ℃ of dry 8-10h, again in 540-560 ℃ of roasting 2.5-3.5h; Feed hydrogen after the roasting and carry out catalyst activation; The oxide of Ni is reduced to have active Ni, 250 ℃ of activation temperatures, pressure 0.1MPa, hydrogen flowing quantity 45ml/min, soak time 48 hours promptly make Pd-Ni/Al ₂O ₃Catalyst, wherein PdCl ₂And Ni (NO ₃) ₂Gross mass be Al ₂O ₃H ₂The 0.5-1% of O quality;

2, liquid phase catalytic hydrogenation

Pd-Ni/Al with step 1 preparation ₂O ₃Catalyst and 50g cyclopentadiene (derive from the dicyclopentadiene cracking, dicyclopentadiene content is at 85-95wt%) add a built-in cooling coil and are equipped with in the agitated reactor of agitating device, add ethanol and acetonitrile mixed solvent; Behind the good seal; At first use nitrogen replacement 3 times, use hydrogen exchange again 3 times, be warming up to 25-40 ℃ of beginning stirring reaction; And Hydrogen Vapor Pressure is controlled at 0.8-1.5MPa, Pd-Ni/Al ₂O ₃The addition of catalyst is the 3-7% of cyclopentadiene quality; The volume ratio of ethanol and acetonitrile is 1:0.2-1 in the mixed solvent; The addition of mixed solvent be the cyclopentadiene quality 5-10 doubly, treat that the cyclopentadiene conversion ratio reaches 98% and stops reaction when above, rectification and purification is carried out in the reactant liquor taking-up.Products therefrom utilizes gas-chromatography analysis.

The preparation parameter setting of embodiment 1-10 is seen table 1, and the conversion ratio and the selectivity of cyclopentadiene are seen table 2.From table 2, can find out; With the cyclopentadiene is in the reaction of the synthetic cyclopentene of material choice property hydrogenation, selects for use ethanol and acetonitrile as mixed solvent, is raw material cyclopentadiene quality 3-7% at catalyst amount; Catalyst activity component Pd/Ni mass ratio is at 1:0.5-3; When active component accounted between the 0.5-1.0% of loaded catalyst gross mass, Hydrogen Vapor Pressure was between 0.8-1.5MPa, and temperature is reacted between 30-35 ℃ all had better conversion rate and selectivity in 1.5-3 hour.Wherein the conversion ratio and the selectivity of the cyclopentadiene that makes of the preparation condition of embodiment 2 are the highest.

Table 1

* the active component addition is meant PdCl ₂And Ni (NO ₃) ₂Gross mass account for Al ₂O ₃H ₂The percentage of O quality.

Table 2

	Cyclopentadiene conversion ratio/%	Cyclopentene selectivity/%
			Implement 1	98.1	97.8
Implement 2	99.5	98.5
			Implement 3	98.5	97.1
Implement 4	98.0	97.5
			Implement 5	99.1	97.2
Implement 6	98.1	98.1
			Implement 7	98.4	97.9
Implement 8	98.7	97.2
			Implement 9	98.1	98.3
Implement 10	98.6	97.0

Claims

1. Pd-Ni/Al ₂O ₃Catalyst is characterized in that: with PdCl ₂And Ni (NO ₃) ₂Be active component, with Al ₂O ₃H ₂O is a catalyst carrier, the catalyst that obtains after being carried on active component on the catalyst carrier;

The mass ratio of Pd and Ni is 1:0.5-3 in the active component.

2. described Pd-Ni/Al of claim 1 ₂O ₃The Preparation of catalysts method comprises each unit process of load and activation, it is characterized in that:

Said load is with PdCl ₂And Ni (NO ₃) ₂Add in the acetum of mass concentration 25-35%, add Al after the stirring and dissolving again ₂O ₃H ₂O stirs and leaves standstill 1.5-2.5h, subsequently in 100-120 ℃ of dry 8-10h, again in 540-560 ℃ of roasting 2.5-3.5h; PdCl ₂And Ni (NO ₃) ₂Gross mass be Al ₂O ₃H ₂The 0.5-1% of O quality, Pd and Ni mass ratio are 1:0.5-3;

Said activation is to feed hydrogen after the roasting to carry out catalyst activation, activation temperature 240-260 ℃, and activation pressure 0.1-0.2MPa, hydrogen flowing quantity 40-50ml/min, soak time 40-50 hour.

3. described Pd-Ni/Al of claim 1 ₂O ₃The purposes of catalyst is characterized in that: prepare in the cyclopentene as Application of Catalyst in cyclopentadiene liquid phase catalytic hydrogenation reduction reaction.