CN1302845C

CN1302845C - Co-Fe-B amorphous alloy catalyst, its preparation method and application

Info

Publication number: CN1302845C
Application number: CNB2004100168846A
Authority: CN
Inventors: 李和兴; 吴跃东
Original assignee: Shanghai Normal University
Current assignee: Shanghai Normal University; University of Shanghai for Science and Technology
Priority date: 2004-03-11
Filing date: 2004-03-11
Publication date: 2007-03-07
Anticipated expiration: 2024-03-11
Also published as: CN1666816A

Abstract

The present invention discloses a Co-Fe-B amorphous alloy catalyst, a preparation method and the application thereof. In the Co-Fe-B amorphous alloy catalyst, the mole percentage of each component meets the following requirements of 0 to 32% of Co, 0.1 to 32% of Fe and 67 to 70% of B. Detected by X-ray diffraction and selective area electronic diffraction, the Co-Fe-B amorphous alloy catalyst has an obvious amorphous structure, and the specific surface area of the Co-Fe-B amorphous alloy catalyst is 19 to 71m<2>/g. The Co-Fe-B amorphous alloy catalyst can be used for preparing ethylamine using liquid phase selective hydrogenation of acetonitrile. The method of the present invention has the advantages of easy operation and essentially no environmental pollution in the process of preparation, and not only has superior catalytic activity and selectivity to acetonitrile hydrogenization, but also has superior catalysis and activity selectivity to reactions of furfural hydrogenization, dextrose hydrogenization, cinnamaldehyde hydrogenization, etc. Thus, the present invention can probably become a novel and environmentally friendly catalysis material of high efficiency.

Description

Co-Fe-B amorphous alloy catalyst and its production and application

Technical field

The present invention relates to a kind of Co-Fe-B amorphous alloy catalyst and preparation method thereof, be specifically related to be used for the selective hydrogenation of liquid phase acetonitrile and prepare ethamine Co-Fe-B amorphous alloy catalyst and preparation method thereof.

Background technology

Nanometer and amorphous alloy are the focus and the fields, forward position of current catalyticing research.Because the unordered and unique texture feature of shortrange order of its long-range, nanometer amorphous alloy all shows excellent catalytic activity and selectivity and sulfur poisoning-resistant ability in many hydrogenation reactions, becomes the catalyst of new generation of tool development prospect 21 century.

Use more amorphous alloy catalyst at present and mainly concentrate on the binary amorphous alloy catalyst, as Ni-B, Co-B, Fe-B, on the catalyst such as Ru-B, about other metal that in binary catalyst, mixes report is arranged also on the document,, and do not appear in the newspapers so far about the Co-Fe-B amorphous alloy catalyst such as interpolation W, Cr, Mo and some rare earth elements.And present industrial widely used liquid phase acetonitrile selective hydrogenation catalyst, catalytic activity and Co-Fe-B catalyst are similar, and (ammonification of industrial employing ethanol prepares ethamine, make catalyst with Raney Ni, and few with the industrial report of liquid phase hydrogenation of acetonitrile), but the selectivity to target product ethamine is generally 37.2%, therefore relevant department's expectation can provide a kind of catalytic activity and the higher catalyst of selectivity, to satisfy industrial needs.

Summary of the invention

One of technical issues that need to address of the present invention are to disclose a kind of Co-Fe-B amorphous alloy catalyst, to overcome catalytic activity and the not high enough defective of selectivity that prior art exists;

Two of the technical issues that need to address of the present invention provide above-mentioned Preparation of catalysts method;

Another technical issues that need to address of the present invention are the commercial Application that disclose above-mentioned catalyst.

Technical conceive of the present invention is such:

The inventor thinks, introduces Fe in the Co-B amorphous alloy, can significantly improve its catalytic activity in liquid phase acetonitrile selective hydrogenation, and the selectivity of target product ethamine is still kept higher level.Activated centre in the Co-Fe-B amorphous alloy catalyst is a metal Co, Fe and B to the facilitation of acetonitrile selective hydrogenation mainly owing to following factor: (1) is considered from geometric effect, it is unordered and the amorphous alloy structure of shortrange order helps improving catalytic activity and the selectivity of catalyst in hydrogenation reaction that the adding of B causes forming unique long-range; In the Co-B amorphous alloy, introduce Fe, produce synergy between Fe and the Co, cause the ligancy of activated centre Co to descend, the randomness factor increases, and the Co-Co bond length shortens simultaneously, shows in the presence of Fe, the coordination degree of unsaturation of activated centre Co increases, the uniformity that active sites distributes increases, and the synergy between active sites Co and the Co increases simultaneously, and these all help catalytic hydrogenation.Consider from electronic effect that (2) have stronger mutual electronic action in this catalyst, portions of electronics is transferred to Co by B and Fe, causing B and Fe is short of electricity, and as the metal Co electron rich in activated centre, helps improving catalytic activity.

In the Co-Fe-B amorphous alloy catalyst of the present invention, the molar percentage of each component is:

Co：0＜～32％，Fe：0.1～32％，B：67～70％。

Co-Fe-B amorphous alloy catalyst of the present invention detects by X-ray diffraction and SEAD, has tangible amorphous structure, and specific area is 19～71m ²/ g, 20～60m more fortunately ²/ g scope.

Preparation of catalysts method of the present invention comprises the steps:

With KBH ₄Concentration is that 0.2～2mol/L, NaOH concentration are that the mixed solution of 0.2mol/L is added dropwise to CoCl ₂And FeCl ₃Mixed solution, control KBH ₄With (Co ²⁺And Fe ²⁺) mol ratio be 6～4: 1, reaction 1～60min reduces fully to guarantee metal ion, reaction temperature is 5～50 ℃, collects the Co-Fe-B amorphous alloy catalyst then from product, and preferably is kept in the absolute ethyl alcohol.

CoCl ₂And FeCl ₃Be commercially available, can adopt conventional method to prepare Fe ³⁺With Co ²⁺Mol ratio be 1: 3～7, preferred 1: 5,

The present invention is applied to this catalyst the selective hydrogenation of acetonitrile liquid phase first and prepares ethamine.This method is easy and simple to handle, substantially do not produce environmental pollution in the preparation process, not only hydrogenation of acetonitrile had excellent catalytic activity and selectivity, and reactions such as furfural hydrogenation, glucose hydrogenation, hydrogenation on cinnamic aldehyde are all had good catalysis and active selectivity, be expected to become efficient and eco-friendly new catalytic material.

Description of drawings

Fig. 1 is the x-ray diffraction pattern collection of illustrative plates.

The specific embodiment

To further describe the present invention by specific embodiment below, enumerating these embodiment only is in order to set forth rather than limit by any way the present invention.

Specific embodiments

Embodiment 1

With KBH ₄Concentration is that 2mol/L, NaOH concentration are that the mixed solution of 0.2mol/L is added dropwise to CoCl ₂And FeCl ₃Mixed solution, Fe ³⁺With Co ²⁺Mol ratio be 1: 5, control KBH ₄And Co ²⁺And Fe ²⁺Mol ratio be 5: 1, reaction 30min reduces fully to guarantee metal ion, reaction temperature is 10 ℃, and the particle that makes then spends deionised water to neutral, removes with absolute ethanol washing and anhydrates, collect the Co-Fe-B amorphous alloy catalyst, be kept in the absolute ethyl alcohol.The catalyst that makes thus by the molar percentage of each component of icp analysis is: Co:26.9%, and Fe:5.2%, B:67.9% adds up to 100%, and it is 55.3m that the BET method records specific area ²/ g.X-ray diffraction pattern is seen Fig. 1.

Embodiment 2～10

Adopt the identical method of embodiment 1, wherein, technological parameter sees Table 2.Fe ³⁺With Co ²⁺Mol ratio see Table 1: you are than seeing Table 1:

Table 1 Fe ³⁺With Co ²⁺Mol ratio

Embodiment	1	2	3	4	5	6	7	8	9	10
Embodiment	1	2	3	4	5	6	7	8	9	10	Mol ratio	1∶3	1∶5	1∶7	1∶4	1∶5	1∶5	1∶5	1∶5	1∶5	1∶5

The composition of the catalyst of table 2 different content Fe, specific area

Embodiment	Catalyst	Temperature ℃	KBH ₄Concentration (mol/L)	The Fe molar content	The Co molar content	Specific area (m ²/g)
Embodiment	Catalyst	Temperature ℃	KBH ₄Concentration (mol/L)	The Fe molar content	The Co molar content	Specific area (m ²/g)	2	Co-B	20	2	0	1	20.9
3	Co-Fe-B	20	2	0.001	0.999	23.9	2	Co-B	20	2	0	1	20.9
3	Co-Fe-B	20	2	0.001	0.999	23.9	4	Co-Fe-B	20	2	0.094	0.906	35.4
5	Co-Fe-B	20	2	0.143	0.857	41.9	4	Co-Fe-B	20	2	0.094	0.906	35.4
5	Co-Fe-B	20	2	0.143	0.857	41.9	6	Co-Fe-B	20	2	0.164	0.836	47.6
7	Co-Fe-B	20	2	0.198	0.802	55.3	6	Co-Fe-B	20	2	0.164	0.836	47.6
7	Co-Fe-B	20	2	0.198	0.802	55.3	8	Co-Fe-B	20	2	0.202	0.798	61.0
9	Co-Fe-B	20	2	0.259	0.741	70.3	8	Co-Fe-B	20	2	0.202	0.798	61.0
9	Co-Fe-B	20	2	0.259	0.741	70.3	10	Fe-B	20	2	1	0	35.0

Embodiment 11～16

The catalyst of embodiment 2～7 is used for the selective hydrogenation of acetonitrile liquid phase prepares the ethamine reaction, the initial pressure of hydrogenation reaction is PH ₂=3.0MPa, reaction temperature is controlled at 110 ℃, is reflected in the 0.5L autoclave to carry out, and adds prepared catalyst, 30ml acetonitrile, the 90ml ethanol of 1.5g, react to the acetonitrile conversion ratio be 100%, result such as table 3:

The catalyst hydrogenation pressure of table 3 different content Fe falls with catalytic activity and compares

Catalyst	Embodiment	2	Embodiment 3	Embodiment 4	Embodiment 5	Embodiment 6	Embodiment 7
Catalyst	Embodiment	2	Embodiment 3	Embodiment 4	Embodiment 5	Embodiment 6	Embodiment 7	React 5 minutes pressure and fall (atm)	3.6	5.0	6.9	8.2	10.2	8.5
Initial hydrogen-absorption speed (mmol/hg)	348.5	484	667.9	793.8	987.4	822.8		React 5 minutes pressure and fall (atm)	3.6	5.0	6.9	8.2	10.2	8.5

By table 3 as seen, mix the Co-B amorphous alloy catalyst of a certain amount of Fe, in the liquid phase acetonitrile hydrogenating reaction, initial hydrogen-absorption speed improves greatly.And the Co-Fe-B catalyst of doping 20wt%Fe has best catalytic activity, reaches 987.4mmol/hg Co, compares with the Co-B catalyst of not mixing Fe, and reaction rate improves 183.3%.

Embodiment 17～22

Adopt and implement 1 same method and prepare Co-Fe-B catalyst, Fe ³⁺With Co ²⁺Mol ratio be 1: 5, temperature such as table 4, the part-structure parameter of Zhi Bei catalyst is listed in table 3 thus.

The catalyst of the different bath temperature preparations of table 4 is formed specific area

Embodiment	Catalyst	Temperature ℃	KBH ₄Concentration (mol/L)	The Fe molar content	The Co molar content	Specific area (m ²/g)
Embodiment	Catalyst	Temperature ℃	KBH ₄Concentration (mol/L)	The Fe molar content	The Co molar content	Specific area (m ²/g)	17	Co-Fe-B	5	2	0.164	0.836	#
18	Co-Fe-B	10	2	0.164	0.836	#	17	Co-Fe-B	5	2	0.164	0.836	#
18	Co-Fe-B	10	2	0.164	0.836	#	19	Co-Fe-B	20	2	0.164	0.836	47.6
20	Co-Fe-B	30	2	0.164	0.836	#	19	Co-Fe-B	20	2	0.164	0.836	47.6
20	Co-Fe-B	30	2	0.164	0.836	#	21	Co-Fe-B	40	2	0.164	0.836	#
22	Co-Fe-B	50	2	0.164	0.836	#	21	Co-Fe-B	40	2	0.164	0.836	#

Above-mentioned catalyst is used for the selective hydrogenation of acetonitrile liquid phase prepares the ethamine reaction, the initial pressure of hydrogenation reaction is PH ₂=3.0MPa, reaction temperature is controlled at 110 ℃, is reflected in the 0.5L autoclave to carry out, and initially adds the prepared catalyst of 1.5g, 30ml acetonitrile, 90ml ethanol, react to the acetonitrile conversion ratio be 100%, result such as table 5:

The catalyst hydrogenation pressure of the different bath temperature preparations of table 5 falls with catalytic activity and compares

Catalyst	Embodiment 17	Embodiment 18	Embodiment 19	Embodiment 20	Embodiment 21	Embodiment 22
Catalyst	Embodiment 17	Embodiment 18	Embodiment 19	Embodiment 20	Embodiment 21	Embodiment 22	React 5 minutes pressure and fall (atm)	12.0	13.0	10.2	6.8	5.6	4.2
Initial hydrogen-absorption speed (mmol/hg)	1161.6	1258.4	968.1	658.3	542.1	406.6	React 5 minutes pressure and fall (atm)	12.0	13.0	10.2	6.8	5.6	4.2

By table 5 as seen, the Co-Fe-B amorphous alloy catalyst of the doping 20wt%Fe of different bath temperatures preparation, bath temperature 5～50 ℃ better, 10 ℃ are best.In the liquid phase acetonitrile hydrogenating reaction, 10 ℃ of initial hydrogen-absorption speeds improve 29.2% than 20 ℃.And catalyst has best catalytic activity, reaches 1258.4mmol/hg Co.

Embodiment 23～28

Adopt and implement 1 same method and prepare the Co-Fe-B catalyst, difference is, Fe: the mol ratio of Co is 1: 5, used KBH ₄Solution concentration is 0.2～2mol/L, and the bath temperature of reduction is 10 ℃.The part-structure parameter of Zhi Bei catalyst is listed in table 5 with this understanding.

Table 6 variable concentrations KBH ₄The catalyst of reduction is formed, specific area

Embodiment	Catalyst	Temperature ℃	KBH ₄Concentration (mol/L)	The Fe molar content	The Co molar content	Specific area (m ²/g)
Embodiment	Catalyst	Temperature ℃	KBH ₄Concentration (mol/L)	The Fe molar content	The Co molar content	Specific area (m ²/g)	23	Co-Fe-B	10	0.2	0.164	0.836	47.5
24	Co-Fe-B	10	0.5	0.164	0.836	47.5	23	Co-Fe-B	10	0.2	0.164	0.836	47.5
24	Co-Fe-B	10	0.5	0.164	0.836	47.5	25	Co-Fe-B	10	1.0	0.164	0.836	47.5
26	Co-Fe-B	10	1.5	0.164	0.836	47.5	25	Co-Fe-B	10	1.0	0.164	0.836	47.5
26	Co-Fe-B	10	1.5	0.164	0.836	47.5	27	Co-Fe-B	10	2.0	0.164	0.836	47.5
28	Co-Fe-B	10	2.5	0.164	0.836	47.5	27	Co-Fe-B	10	2.0	0.164	0.836	47.5

Above-mentioned catalyst is used for the selective hydrogenation of acetonitrile liquid phase prepares the ethamine reaction, the initial pressure of hydrogenation reaction is PH ₂=3.0MPa, reaction temperature is controlled at 110 ℃, is reflected in the 0.5L autoclave to carry out, and initially adds the prepared catalyst of 1.5g, 30ml acetonitrile, 90ml ethanol, react to the acetonitrile conversion ratio be 100%, result such as table 7:

Table 7 different K BH ₄The catalyst hydrogenation pressure of reduction falls with catalytic activity and compares

Catalyst	Embodiment 23	Embodiment 24	Embodiment 25	Embodiment 26	Embodiment 27	Embodiment 28
Catalyst	Embodiment 23	Embodiment 24	Embodiment 25	Embodiment 26	Embodiment 27	Embodiment 28	React 5 minutes pressure and fall (atm)	3.8	7.0	8.4	10.1	13.0	11.2
Initial hydrogen-absorption speed (mmol/hg)	367.8	677.6	813.1	977.7	1258.4	1084.2	React 5 minutes pressure and fall (atm)	3.8	7.0	8.4	10.1	13.0	11.2

By table 7 as seen, different K BH ₄The Co-Fe-B amorphous alloy catalyst of the doping 20wt%Fe of reduction preparation, KBH ₄Concentration is 0.2～2.5mol/L, and 2.0mol/L is best.In the liquid phase acetonitrile hydrogenating reaction, 2.0mol/L KBH ₄The catalyst of reduction preparation has best catalytic activity, reaches 1258.4mmol/hg Co.

Claims

1. a Co-Fe-B amorphous alloy catalyst is characterized in that, component and molar percentage are: Co:0＜～32%, Fe:0.1～32%, B:67～70%;

Specific area is 19～71m ²/ g.

2. require 1 described Preparation of catalysts method according to claim, it is characterized in that comprising the steps: KBH ₄, NaOH mixed solution be added dropwise to CoCl ₂And FeCl ₃Mixed solution, control KBH ₄With (Co ²⁺And Fe ²⁺) mol ratio be 6～4: 1, reaction 1～60min, reaction temperature is 5～50 ℃, collects the Co-Fe-B amorphous alloy catalyst then from product;

Fe in the mixed solution ³⁺With Co ²⁺Mol ratio be 1: 3～7.

3. require 2 described Preparation of catalysts methods according to claim, it is characterized in that the Co-Fe-B amorphous alloy catalyst is kept in the absolute ethyl alcohol.

4. require 2 described Preparation of catalysts methods according to claim, it is characterized in that CoCl ₂And FeCl ₃Mixed solution in Fe ³⁺With Co ²⁺Mol ratio be 1: 5.

5. require 2 described Preparation of catalysts methods according to claim, it is characterized in that, KBH ₄Concentration is that 0.2～2mol/L, NaOH concentration are that the mixed solution of 0.2mol/L is added dropwise to CoCl ₂And FeCl ₃Mixed solution.

6. the described catalyst of claim 1 prepares application in the ethamine in the selective hydrogenation of acetonitrile liquid phase.