CN106607035A - Modified alpha-alumina carrier and its preparation method and use - Google Patents
Modified alpha-alumina carrier and its preparation method and use Download PDFInfo
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- CN106607035A CN106607035A CN201510686188.4A CN201510686188A CN106607035A CN 106607035 A CN106607035 A CN 106607035A CN 201510686188 A CN201510686188 A CN 201510686188A CN 106607035 A CN106607035 A CN 106607035A
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Abstract
The invention relates to a modified alpha-alumina carrier and a preparation method thereof. Cobalt is used in carrier preparation and the molded alpha-alumina carrier is subjected to acid treatment so that the modified alpha-alumina carrier is obtained. The invention also relates to a silver catalyst using the modified alpha-alumina carrier and a preparation method of the silver catalyst. The silver catalyst supported by the modified alpha-alumina carrier has good activity and selectivity in the ethylene oxidation production of ethylene oxide. The preparation method utilizes easily available raw materials and has simple processes. The modified alpha-alumina carrier and the silver catalyst have a wide application prospect.
Description
Technical field
The invention belongs to catalyst carrier and catalyst preparation technical field, and in particular to a kind of modified Alpha-alumina
Carrier and its preparation and application.
Background technology
Oxidation of ethylene mainly generates oxirane under silver catalyst effect, while side reaction also occurs generates two
Carbonoxide and water etc., wherein activity, selectivity and stability are the main performance index of silver catalyst.It is so-called
Activity refers to that process for ethylene oxide production reaches reaction temperature required during certain reaction load；Reaction temperature is got over
Low, the activity of catalyst is higher.So-called selectivity refers to that ethylene changes into the molal quantity of oxirane in reaction
With the ratio of the overall reaction molal quantity of ethylene.So-called stability is then expressed as the fall off rate of activity and selectivity, under
The stability of reduction of speed rate more small catalyst is better.
Using high activity, high selectivity and have good stability during oxidation of ethylene produces oxirane
Silver catalyst can greatly improve economic benefit, therefore manufacture high activity, high selectivity and good stability
Silver catalyst is the Main way of silver catalyst research.The performance of silver catalyst is except the composition and system with catalyst
Preparation Method has outside important relationship, and the performance of the carrier for also using with catalyst and its preparation have important relationship.
At present, or the silver catalyst selectivity on market is good, but activity is not so good；Activity is good, selects
Property is not so good.Therefore, in view of the needs in market, need that research and development are a kind of can both to have improved silver catalyst at present
Activity, stability, can improve the treatment technology of the selective carrier of silver catalyst again, and the silver being made from it is urged
Agent and its application process.
The content of the invention
The technical problem to be solved is for above-mentioned the deficiencies in the prior art, there is provided a kind of modified alpha-oxygen
Change alumina supporter, the carrier has higher specific surface area and intensity, and has more macropore.To be modified this described
Silver catalyst made by alpha-alumina supports, is conducive to the dispersion of chain carrier, and is conducive to product
Desorption.Therefore, the modified alpha-alumina supports are applied to into oxidation of ethylene production reacting ethylene oxide process, are carried
High its activity and selectivity, especially significantly improves selectivity.
For this purpose, first aspect present invention provides a kind of modified alpha-alumina supports, it is carried by Alpha-alumina containing cobalt
Body is obtained through acid solution process.
In the present invention, the alpha-alumina supports containing cobalt by the precursor mixture Jing molding of alpha-alumina supports containing cobalt,
It is dried and roasting is obtained, wherein, the precursor mixture of alpha-alumina supports containing cobalt is included：
Component a, three water A12O3；
Component b, false water A12O3；
Component d, mineralizer；
Component e, cobalt simple substance and/or cobalt compound；
Component f, binding agent；
Component g, water；And it is optional
Component c, weight alkaline earth metal compound.
In the present invention, the precursor mixture of alpha-alumina supports containing cobalt is by solid constituent a-e gross weight meter
Composition is as follows：
Component g, the water of surplus.
Preferably, the precursor mixture of alpha-alumina supports containing cobalt presses the composition of solid constituent a-e gross weight meter
It is as follows：
Component g, the water of surplus.
In some embodiments of the invention, the mineralizer is fluoride.
The present invention other embodiments in, the cobalt compound include cobalt oxide, cobalt carbonate, cobalt nitrate,
At least one in cobaltous chloride and cobaltous sulfate.It is preferred that the cobalt compound is cobalt oxide and/or cobalt nitrate.
Second aspect present invention provides a kind of modified alpha-alumina supports as described in the first aspect of the invention
Preparation method, it includes：
Step A, by the mixing of component a-g, is obtained the precursor mixture of alpha-alumina supports containing cobalt；
Step B, will contain cobalt alpha-alumina supports precursor mixture molding, and be dried, roasting, be obtained α containing cobalt-
Alumina support；
Step C, will contain cobalt alpha-alumina supports carries out the prepared modified alpha-alumina support precursor of acid solution process；
Step D, is washed to modified alpha-alumina support precursor, is dried and roasting, and modified alpha-oxidation is obtained
Alumina supporter；
Wherein, in step C, using acid compound aqueous solution to alpha-alumina supports containing cobalt carry out acid solution
Process.
In the preparation method of the modified alpha-alumina supports of the present invention, the hydrogen of the aqueous solution of the acid compound
Ion concentration is 0.01-4mol/L.It is preferred that the hydrogen ion concentration of the aqueous solution of the acid compound is
0.05-1.5mol/L。
In the preparation method of the modified alpha-alumina supports of the present invention, in step C, the alpha-oxidation containing cobalt
Alumina supporter is 1 with the weight ratio of the aqueous solution of the acid compound:(1-150).It is preferred that the α containing cobalt-oxygen
It is 1 to change alumina supporter with the weight ratio of the aqueous solution of the acid compound:(20-60).
The present invention modified alpha-alumina supports preparation method in, the acid compound include mineral acid and
/ or Acidic inorganic salts, wherein the mineral acid includes at least one of sulphuric acid, nitric acid, hydrochloric acid and oxalic acid；It is described
Acidic inorganic salts include ammonium nitrate and/or ammonium chloride.
In the preparation method of the modified alpha-alumina supports of the present invention, in step C, what the acid solution was processed
Temperature is 20-200 DEG C.It is preferred that the temperature that the acid solution is processed is 40-100 DEG C.The time that the acid solution is processed is
0.2-3h.It is preferred that the time that the acid solution is processed is 0.5-1.5h.
Third aspect present invention provide a kind of silver catalyst, comprising modified alpha as described in the first aspect of the invention-
Modified alpha-alumina supports and be carried on prepared by alumina support or as described in respect of the second aspect of the invention method
Silver-colored simple substance in the modified alpha-alumina supports.
Fourth aspect present invention provides a kind of preparation method of the silver catalyst as described in third aspect present invention,
Including：
Step M：The modified alpha-alumina supports or the present invention the described in first aspect present invention are impregnated with impregnation liquid
Modified alpha-alumina supports prepared by two aspect methods describeds；
Step N：Solid-liquid separation removes impregnation liquid.
In the preparation method of the silver catalyst of the present invention, impregnation liquid composition by weight is as follows：
The water of surplus.
Preferably, impregnation liquid composition by weight is as follows：
The water of surplus.
Fifth aspect present invention provides a kind of modified alpha-alumina supports as described in the first aspect of the invention, such as
Modified alpha-alumina supports, the silver as described in third aspect present invention prepared by second aspect present invention methods described
Catalyst or the silver catalyst such as the preparation of fourth aspect present invention methods described produce oxirane in oxidation of ethylene
During application.
Specific embodiment
To make the present invention easier to understand, below in conjunction with embodiment the present invention is described in detail, these enforcements
Example only plays illustrative effect, it is not limited to the range of application of the present invention.
Existing alumina support macropore is few, and specific surface area is little.Need research and development one kind both can improve at present to urge
The activity of agent, stability, can improve the treatment technology of the selective carrier of silver catalyst again, and be made from it
Silver catalyst and its application process.
Therefore, first aspect present invention is related to a kind of modified alpha-alumina supports, and it is by alpha-alumina supports containing cobalt
It is obtained through acid solution process.
In the present invention, the alpha-alumina supports containing cobalt by the precursor mixture Jing molding of alpha-alumina supports containing cobalt,
It is dried and roasting is obtained, wherein, the precursor mixture of alpha-alumina supports containing cobalt is included：
Component a, three water A12O3；
Component b, false water A12O3；
Component c, weight alkaline earth metal compound (optional)；
Component d, mineralizer；
Component e, cobalt simple substance and/or cobalt compound；
Component f, binding agent；And
Component g, water.
In the present invention, the modified alpha-alumina supports are a kind of porous Alpha-aluminas containing cobalt through acid solution process
Carrier, and due to cobalt element contained in alpha-alumina supports containing cobalt be in its preparation process with other compositions
What the mode of common mixing was added, therefore in alpha-alumina supports containing cobalt and modified alpha-alumina supports containing cobalt
Cobalt element is equally distributed.
In the present invention, component a is three water A12O3, and be the water α-A1 of graininess three2O3, its granularity is
The mesh of 50 mesh -500.Three water A12O3Presence can increase the duct of carrier, so as to form porous α-A12O3Carrier.
In the present invention, component b is false water A12O3, its granularity is preferably greater than equal to 200 mesh.
In the present invention, component c is attached most importance to alkaline earth metal compound, and it can improve the performance of carrier.The present invention
Described heavy alkaline earth metal compound is the compound of strontium and/or barium, preferably include strontium and/or barium oxide,
At least one in sulfate, acetate, nitrate, carbonate and oxalates.The particularly preferred heavy alkaline earth
Metallic compound is at least one in Barium monoxide, barium sulfate, barium nitrate and brium carbonate.
In the present invention, it is preferred to component d mineralizer is fluoride-mineralization agent.Fluoride-mineralization of the present invention
The transformation of crystal for being added to accelerated oxidation aluminum of agent.It is preferred that fluoride of the present invention is inorganic fluoriding
One or more in thing, including fluohydric acid gas, ammonium fluoride, aluminium fluoride, Afluon (Asta) and cryolite.Particularly preferably
The fluoride is ammonium fluoride.
In the present invention, component f binding agent can be with component b one water A1 of vacation2O3Alumina gel is generated, by each group
Divide and be bonded together, become the paste of extrudable molding.Binding agent preferably used is acid, bag in the present invention
Include at least one in nitric acid, formic acid, acetic acid, propanoic acid and hydrochloric acid.When using acid as binding agent, preferably
Nitric acid, and it is hybridly prepared into into aqueous solution of nitric acid with water.
In some embodiments of the invention, preferred nitric acid and the weight ratio of water are 1:(1.25-10).It is more excellent
Choosing, nitric acid is 1 with the weight ratio of water:(2-4).
In the present invention, it is also possible to which Alumina gel partly or entirely replaces the vacation one of the binding agent of component f and component b
Water A12O3。
In the present invention, the precursor mixture of alpha-alumina supports containing cobalt is by solid constituent a-e gross weight meter
Composition is as follows：
Component g, the water of surplus.
Preferably, the precursor mixture of alpha-alumina supports containing cobalt presses the composition of solid constituent a-e gross weight meter
It is as follows：
Component g, the water of surplus.
In some embodiments of the invention, the cobalt compound include cobalt oxide, cobalt carbonate, cobalt nitrate,
At least one in cobaltous chloride and cobaltous sulfate.It is preferred that the cobalt compound is cobalt oxide and/or cobalt nitrate.
Second aspect present invention provides a kind of modified alpha-alumina supports as described in the first aspect of the invention
Preparation method, it includes：
Step A, by the mixing of component a-g, is obtained the precursor mixture of alpha-alumina supports containing cobalt；
Step B, will contain cobalt alpha-alumina supports precursor mixture molding, and be dried, roasting, be obtained α containing cobalt-
Alumina support；
Step C, will contain cobalt alpha-alumina supports carries out the prepared modified alpha-alumina support precursor of acid solution process；
Step D, is washed to modified alpha-alumina support precursor, is dried and roasting, and modified alpha-oxidation is obtained
Alumina supporter；
Wherein, in step C, using acid compound aqueous solution to alpha-alumina supports containing cobalt carry out acid solution
Process.
According to the inventive method, the composition of the precursor mixture of alpha-alumina supports containing cobalt is as follows：
Component a, the water Al of -500 purpose of 50 mesh three2O3；
Component b, more than or equal to the water Al of vacation one of 200 mesh2O3；
Component c, accounts for the heavy alkaline earth metal compound that component a-e gross weight is 0-2% (weight)；
Component d, fluoride-mineralization agent；
Component e, is counted with the weight of cobalt element and accounts for cobalt simple substance of the component a-e gross weight as 0.001%-5% and/or contain
Cobalt compound；
Component f, binding agent；And
Component g, the water of surplus.
In the preparation method of the modified alpha-alumina supports of the present invention, the hydrogen of the aqueous solution of the acid compound
Ion concentration is 0.01-4mol/L.It is preferred that the hydrogen ion concentration of the aqueous solution of the acid compound is
0.05-1.5mol/L。
In the preparation method of the modified alpha-alumina supports of the present invention, in step C, the alpha-oxidation containing cobalt
Alumina supporter is 1 with the weight ratio of the aqueous solution of the acid compound:(1-150).It is preferred that the α containing cobalt-oxygen
It is 1 to change alumina supporter with the weight ratio of the aqueous solution of the acid compound:(20-60).
The present invention modified alpha-alumina supports preparation method in, the acid compound include mineral acid and
/ or Acidic inorganic salts, wherein the mineral acid includes at least one of sulphuric acid, nitric acid, hydrochloric acid and oxalic acid；It is described
Acidic inorganic salts include ammonium nitrate and/or ammonium chloride.
In the present invention, after is mediated uniformly the mixture in step A, paste is generally yielded.To the present invention
Advantageously, generally first by component a-e (if all if use) mix homogeneously after, in proceeding to kneader, so
Add component f and g to be mediated afterwards, be uniformly kneaded into paste, be especially kneaded into the cream of extrudable molding
Shape thing；Molded body is obtained after paste molding, the molded body can be dried to aqueous 10% (weight) below, done
Dry temperature is 80-120 DEG C, and drying time is controlled in 1-24 hours according to moisture.The shape of gained molded body
Can be annular, spherical, cylindricality, porous column shape or other arbitrary shapes.
Some specific embodiments of the invention, in stepb, generally at 1000-1500 DEG C, preferably
Roasting is carried out at a temperature of 1000-1400 DEG C.Roasting time is no less than 1 hour.Roasting time is usually 2-24
Hour.It is preferred that roasting time is 2-8 hours.Aluminium oxide is set to be completely converted into α-A1 substantially by roasting2O3,
Such as more than 90% is converted into α-A12O3, obtain alpha-alumina supports.
In the present invention, it is preferred to the acid solution is processed carry out under agitation.
In the present invention, it is preferred to the acid solution is processed carry out under uniform temperature (such as by heating), according to this
Inventor's research of invention finds, carry out in a heated condition acid solution process can more preferable dealuminzation, increase carrier
Specific surface area, and increase macropore.
According to the inventive method, in step C, the temperature that the acid solution is processed is 20-200 DEG C.It is preferred that described
The temperature of acid solution process is 40-100 DEG C.
According to the inventive method, in step C, the time that the acid solution is processed is 0.2-3h.It is preferred that the acid
The time of liquid process is 0.5-1.5h.
In some embodiments of the invention, in step D, the temperature of the roasting is 400-1000 DEG C.It is excellent
The temperature for selecting the roasting is 500-800 DEG C.It is furthermore preferred that the temperature of the roasting is 540 DEG C.
In other embodiments of the present invention, in step D, the time of the roasting is at least 1 hour.
It is preferred that the time of the roasting is 2-24 hours.It is more highly preferred to, the time of the roasting is 4-10 hours.
In some other embodiment of the present invention, in step D, preferably use deionized water wash and be modified
Alpha-alumina supports precursor, is washed modified alpha-alumina support precursor to filtrate in neutrality by deionized water,
Then process is dried again.The temperature of the drying is 60-180 DEG C.It is preferred that the temperature of the drying is
80-120℃。
The modified alpha-alumina supports for obtaining prepared according to the methods of the invention, are by alpha-alumina supports Jing containing cobalt
It is obtained after peracid treatment, be also referred to as modified alpha-alumina supports containing cobalt or containing cobalt improved alpha-alumina supports.This
The there is provided alpha-alumina supports of invention have following characteristics：Specific surface area is 0.2-2.0m2/ g, pore volume is
0.35-0.85mL/g, water absorption rate >=30%, crushing strength is 20-140N/ grains.
In the present invention, cobalt element is added in the preparation process of carrier, therefore, it equally equably divides
Cloth is in modified alpha-alumina supports.The addition of cobalt element, is conducive to improving the specific surface area and intensity of carrier,
And the process of acid compound, further increase duct and the specific surface area of carrier.
The present invention has carried out acid treatment to the alpha-alumina supports containing cobalt, can so play the effect of cobalt element,
The effect of acid treatment can be played again.This contains the alpha-alumina supports of cobalt after acid treatment, and alumina wafer can diminish,
There are more folds in surface, increases the specific surface area of carrier, improves the activity of silver catalyst；Macropore increases
It is many, the desorption of oxirane is increased, improve the selectivity of silver catalyst.After acid treatment, cobalt element
Still it is uniformly distributed in the carrier.
Third aspect present invention is related to a kind of silver catalyst, comprising modified alpha-oxygen as described in the first aspect of the invention
Change alumina supporter or the as described in respect of the second aspect of the invention modified alpha-alumina supports of method preparation and be carried on institute
The silver-colored simple substance in modified alpha-alumina supports is stated, wherein, the silver-colored simple substance loaded in the modified alpha-alumina supports
Content be about 16.1% (weight).
Fourth aspect present invention is related to a kind of preparation method of silver catalyst described in third aspect present invention, including：
Step M：The modified alpha-alumina supports or the present invention the described in first aspect present invention are impregnated with impregnation liquid
Modified alpha-alumina supports prepared by two aspect methods describeds；
Step N：Solid-liquid separation removes impregnation liquid.
In the preparation method of the silver catalyst of the present invention, impregnation liquid composition by weight is as follows：
The water of surplus.
Preferably, impregnation liquid composition by weight is as follows：
The water of surplus.
In the present invention, preferably the silver compound is at least one in silver oxide, silver nitrate and silver oxalate.
In the present invention, preferably the alkali metal promoter for the one kind in the compound of lithium, sodium, potassium, rubidium and caesium or
It is various.It is furthermore preferred that the alkali metal promoter is in cesium sulfate, cesium nitrate, lithium nitrate and potassium hydroxide
Plant or various.Most preferably, the alkali metal promoter is cesium sulfate.
In the present invention, preferably the base earth metal promoter is the one kind or many in the compound of magnesium, calcium, strontium and barium
Kind.It is furthermore preferred that the base earth metal promoter be the oxide of magnesium, calcium, strontium and barium, oxalates, sulfate,
One or more in acetate and nitrate.
In the present invention, preferably the rhenium auxiliary agent is in oxide, perrhenic acid, perrhenic acid caesium and the ammonium perrhenate of rhenium
One or more.It is furthermore preferred that the rhenium auxiliary agent is ammonium perrhenate.
In the present invention, preferably the organic amine is in pyridine, butylamine, ethylenediamine, 1,3- propane diamine and ethanolamine
One or more.It is furthermore preferred that the organic amine is ethylenediamine and/or ethanolamine.It is highly preferred, it is described
Organic amine is ethylenediamine and ethanolamine mixtures.
In some embodiments of the invention, also including the coassist agent of rhenium auxiliary agent in the impregnation liquid, with further
Improve activity, selectivity and the stability of gained silver catalyst.The coassist agent of the rhenium auxiliary agent includes element week
The compound of arbitrary transition metal in phase table, or the mixture of several transistion metal compounds.It is preferred that the rhenium is helped
The coassist agent of agent is group vib and the oxyacid and its salt of VIIB races element, including wolframic acid, sodium tungstate, wolframic acid
One or more in potassium, ammonium tungstate, wolframic acid caesium, molybdic acid, ammonium molybdate and ammonium metatungstate.Its consumption is 0-1000wt
ppm.It is preferred that its consumption is 0-500wt ppm.
In the present invention, the dipping process can be carried out under subatmospheric pressure conditions.It is preferred that being less than in vacuum
Carry out under conditions of 10mmHg.Dip time is preferably 10-60min.
In the present invention, the preferably solid is separated into leaching.
In the present invention, the silver compound be major catalyst, the alkali metal promoter, base earth metal promoter, rhenium
Auxiliary agent etc. is catalyst promoter.
In some embodiments of the invention, the modified alpha-alumina supports that prepared by said method are can root using before
Activated according to needs.Activation can be carried out in air or oxygen content are not more than the nitrogen oxygen atmosphere of 21v%.Its
Activation temperature is 180-700 DEG C.It is preferred that activation temperature is 200-500 DEG C.Its soak time is 1-120min.It is excellent
Soak time is selected to be 2-60min.
Fifth aspect present invention provides modified alpha-alumina supports as described in the first aspect of the invention, such as this
Modified alpha-alumina supports prepared by bright second aspect methods described, the silver catalysis as described in third aspect present invention
Agent or the silver catalyst such as the preparation of fourth aspect present invention methods described produce oxirane process in oxidation of ethylene
In application.
Silver catalyst is used in epoxidation of ethylene according to obtained in the method for the invention, the epoxidation reaction
Condition is conventional reaction condition in the art, and such as the reaction temperature can be 200-275 DEG C.
" water " one word used in the present invention, in the case where not specifying, refers to deionized water.
Term " optional " of the present invention refers to and contains or not contain, also refers to add or be added without.
The specific surface area of carrier is surveyed according to international test standards ISO-9277 using nitrogen physisorption BET method
It is fixed.It is, for example possible to use U.S. Kang Ta companies NOVA2000e type nitrogen physisorptions instrument determines the ratio of carrier
Surface area.
The pore volume of carrier is determined using mercury injection method.It is, for example possible to use Merck ＆ Co., Inc of U.S. AutoPore9510 types
Mercury injection apparatus determines the pore volume of carrier.
The amount of alkaline earth metal compound can be by being calculated in carrier.
The side pressure strength of carrier, it is for instance possible to use Dalian Chemical Research ＆. Design Inst. produces the types of DL II intelligence granule
Intensity measuring device, randomly selects 30 support samples, averages after measure radial direction crushing strength and obtains.
Term " water absorption rate " used refers to that the carrier saturation of unit mass adsorbs the volume of water, unit in the present invention
It is mL/g.Assay method is as follows：A certain amount of carrier is weighed first (it is assumed that its quality is m1), in boiling water
Boil to take out to be erected on the moderate wet gauze of water content by carrier after 1h and remove the unnecessary moisture of carrier surface, most
The quality of the carrier after absorption water is weighed afterwards (it is assumed that m2), the water absorption rate of carrier is calculated as follows.
Water absorption rate=(m2-m1)/m1/ρWater
Wherein ρWaterIt is the density of water under temperature of the measurement, atmospheric pressure.
The measure of catalyst performance：Be related in the present invention various silver catalyst laboratory microreactors (with
Lower abbreviation " micro- anti-") evaluating apparatus test its initial activity and selectivity.It is anti-used in micro anti-evaluation device
The stainless steel tube that device is internal diameter 4mm, reaction tube is answered to be placed in heating mantle.The admission space of catalyst is 1mL,
Inert filler is arranged at bottom, makes beds be located at the flat-temperature zone of heating mantle.The catalyst activity that the present invention is adopted
With selective condition determination such as table 1：
The condition determination of the catalyst activity and selectivity of table 1
METHOD FOR CONTINUOUS DETERMINATION reactor enters after above-mentioned reaction condition is stably reached, exit gas is constituted.Measurement result is entered
Selectivity S is calculated as follows after the correction of row volume contraction：
Wherein Δ EO is reactor outlet gas and inlet gas ethylene oxide concentration difference, Δ CO2It is reactor outlet
Gas is poor with gas concentration lwevel in inlet gas, takes the test of the average as the same day of more than 10 groups test datas
As a result.
Modified alpha-alumina supports provided by the present invention and its silver catalyst of load have advantages below：
(1) the modified alpha-alumina supports that the present invention is provided, by adding cobalt element in carrier preparation process
And the alpha-alumina supports of molding are carried out with the process of acid compound, improve the ratio table of alpha-alumina supports
Area and crushing strength, the active component after being conducive to it is dispersed；And cobalt element is uniformly distributed to carrying
High catalyst activity is helpful, is conducive to the reservation of aperture, increases carrier specific surface area；Alpha-alumina containing cobalt is carried
Body surface face is in alkalescence, is conducive to oxirane to be desorbed, and improves selectivity.
(2) the modified alpha-alumina supports macropore that the present invention is provided is more, and water absorption rate is high, is conducive to oxirane
Desorption, is conducive to improving selectivity.
(3) silver catalyst by made by the modified alpha-alumina supports of the present invention that the present invention is provided, in ethylene
During oxidation production oxirane, good selectivity and activity are unexpectedly shown.
(4) present invention is easy to obtain to the raw material that alpha-alumina supports are modified, and preparation method step
Simply.
(5) the modified alpha-alumina supports and silver catalyst that the present invention is provided have broad application prospect.
Embodiment
Comparative example 1
By the water α-A1 of -500 purpose of 200 mesh three2O3The water A1 of vacation one of 372g, the mesh of 200 mesh -4002O3112g、
MgF23g and Ba (NO3)2The solid mixture of 0.5g is put into mix homogeneously in blender, then proceeds to kneader,
Add dust technology (nitric acid:Water=1:3, weight ratio) 90mL, the paste of extrudable molding is kneaded into, extrude
It is shaped to the five hole columns of external diameter 8.0mm, long 6.0mm, internal diameter 1.0mm.By the five holes column in
10h is dried at 80-120 DEG C, makes free water content be reduced to 10% (weight) below, molding alpha-oxidation is obtained
Alumina supporter precursor.Then the precursor is put in electric furnace, Jing 30h are increased to 1400 DEG C from room temperature, afterwards constant temperature
2h, is obtained white α-A12O3Carrier.By obtained white α-A12O3Carrier is named as Z-1, and determines
Its crushing strength, water absorption rate and specific surface area, the results are shown in Table 2.
Comparative example 2
Being put in the raw material of blender mixing also includes Co (NO3)2.6H2O 1.48g, remaining is identical with comparative example 1.
By the obtained white-A1 of α containing cobalt2O3Carrier is named as Z-2, and determines its crushing strength, water absorption rate and ratio
Surface area, the results are shown in Table 2.
Comparative example 3
It is 1 by the weight ratio of alpha-alumina supports and the aqueous solution of acid compound:20 prepare 400g 0.5mol/L
HNO3Solution, and by HNO3Solution is heated to 80 DEG C, weighs 20g Z-1 carriers and is put into HNO3Solution,
After stirring 0.5h, acid solution alpha-alumina supports precursor is taken out, deionized water cleaning is to filtrate pH value
7 or so；Then acid solution alpha-alumina supports precursor is put into baking oven and is dried 10h in 100 DEG C, after dry acid
Liquid alpha-alumina supports precursor is put into Muffle furnace in 540 DEG C of roastings 4 hours, and modified alpha-alumina supports are obtained.
Obtained modified alpha-alumina supports are named as into Z-3, and determine its crushing strength, water absorption rate and specific surface
Product, the results are shown in Table 2.
Embodiment 1
It is 1 by the weight ratio of alpha-alumina supports and the aqueous solution of acid compound:20 prepare 400g 0.5mol/L
HNO3Solution, and by HNO3Solution is heated to 80 DEG C, weighs 20g Z-2 carriers and is put into HNO3Solution,
After stirring 0.5h, acid solution alpha-alumina supports precursor is taken out, deionized water cleaning is to filtrate pH value
7 or so.Then acid solution alpha-alumina supports precursor is put into baking oven and is dried 10h in 100 DEG C, after dry acid
Liquid alpha-alumina supports precursor is put into Muffle furnace in 540 DEG C of roastings 4 hours, and modified alpha-alumina supports are obtained.
Obtained modified alpha-alumina supports are named as into Z-4, and determine its crushing strength, water absorption rate and specific surface
Product, the results are shown in Table 2.
Embodiment 2
It is 1 by the weight ratio of alpha-alumina supports and the aqueous solution of acid compound:20 prepare 400g 0.01mol/L
HNO3Solution, and by HNO3Solution is heated to 80 DEG C, weighs 20g Z-2 carriers and is put into HNO3Solution,
After stirring 0.5h, acid solution alpha-alumina supports precursor is taken out, deionized water cleaning is to filtrate pH value
7 or so.Then acid solution alpha-alumina supports precursor is put into baking oven and is dried 10h in 100 DEG C, after dry acid
Liquid alpha-alumina supports precursor is put into Muffle furnace in 540 DEG C of roastings 4 hours, and modified alpha-alumina supports are obtained.
Obtained modified alpha-alumina supports are named as into Z-5, and determine its crushing strength, water absorption rate and specific surface
Product, the results are shown in Table 2.
Embodiment 3
It is 1 by the weight ratio of alpha-alumina supports and the aqueous solution of acid compound:20 prepare 400g 1.5mol/L
HNO3Solution, and by HNO3Solution is heated to 80 DEG C, weighs 20g Z-2 carriers and is put into HNO3Solution,
After stirring 0.5h, acid solution alpha-alumina supports precursor is taken out, deionized water cleaning is to filtrate pH value
7 or so.Then acid solution alpha-alumina supports precursor is put into baking oven and is dried 10h in 100 DEG C, after dry acid
Liquid alpha-alumina supports precursor is put into Muffle furnace in 540 DEG C of roastings 4 hours, and modified alpha-alumina supports are obtained.
Obtained modified alpha-alumina supports are named as into Z-6, and determine its crushing strength, water absorption rate and specific surface
Product, the results are shown in Table 2.
Embodiment 4
It is 1 by the weight ratio of alpha-alumina supports and the aqueous solution of acid compound:60 prepare 1200g 0.5mol/L
HNO3Solution, and by HNO3Solution is heated to 80 DEG C, weighs 20g Z-2 carriers and is put into HNO3Solution,
After stirring 0.5h, acid solution alpha-alumina supports precursor is taken out, deionized water cleaning is to filtrate pH value
7 or so.Then acid solution alpha-alumina supports precursor is put into baking oven and is dried 10h in 100 DEG C, after dry acid
Liquid alpha-alumina supports precursor is put into Muffle furnace in 540 DEG C of roastings 4 hours, and modified alpha-alumina supports are obtained.
Obtained modified alpha-alumina supports are named as into Z-7, and determine its crushing strength, water absorption rate and specific surface
Product, the results are shown in Table 2.
Embodiment 5
It is 1 by the weight ratio of alpha-alumina supports and the aqueous solution of acid compound:20 prepare 400g 0.5mol/L
HNO3Solution, and by HNO3Solution is heated to 40 DEG C, weighs 20g Z-2 carriers and is put into HNO3Solution,
After stirring 0.5h, acid solution alpha-alumina supports precursor is taken out, deionized water cleaning is to filtrate pH value
7 or so.Then acid solution alpha-alumina supports precursor is put into baking oven and is dried 10h in 100 DEG C, after dry acid
Liquid alpha-alumina supports precursor is put into Muffle furnace in 540 DEG C of roastings 4 hours, and modified alpha-alumina supports are obtained.
Obtained modified alpha-alumina supports are named as into Z-8, and determine its crushing strength, water absorption rate and specific surface
Product, the results are shown in Table 2.
Embodiment 6
It is 1 by the weight ratio of alpha-alumina supports and the aqueous solution of acid compound:20 prepare 400g 0.5mol/L
HNO3Solution, and by HNO3Solution is heated to 80 DEG C, weighs 20g Z-2 carriers and is put into HNO3Solution,
After stirring 1h, acid solution alpha-alumina supports precursor is taken out, deionized water cleaning is 7 to filtrate pH value
Left and right.Then acid solution alpha-alumina supports precursor is put into baking oven and is dried 10h in 100 DEG C, after dry acid
Liquid alpha-alumina supports precursor is put into Muffle furnace in 540 DEG C of roastings 4 hours, and modified alpha-alumina supports are obtained.
Obtained modified alpha-alumina supports are named as into Z-9, and determine its crushing strength, water absorption rate and specific surface
Product, the results are shown in Table 2.
The physical parameter of the carrier of table 2
| Carrier is originated | Support samples | Crushing strength (N/ grains) | Water absorption rate (%) | Specific surface area (m2/g) |
| Comparative example 1 | Z-1 | 48 | 51.14 | 0.752 |
| Comparative example 2 | Z-2 | 59 | 52.46 | 1.065 |
| Comparative example 3 | Z-3 | 41 | 50.93 | 1.187 |
| Embodiment 1 | Z-4 | 53 | 52.19 | 1.356 |
| Embodiment 2 | Z-5 | 57 | 52.32 | 1.169 |
| Embodiment 3 | Z-6 | 50 | 51.56 | 1.621 |
| Embodiment 4 | Z-7 | 52 | 52.06 | 1.402 |
| Embodiment 5 | Z-8 | 56 | 52.27 | 1.178 |
| Embodiment 6 | Z-9 | 51 | 52.02 | 1.411 |
Above-mentioned comparative example 2, embodiment 1-6 is compared as can be seen that in carrier with comparative example 1 with comparative example 3
Add after cobalt element in preparation process, the intensity and specific surface area of carrier are improved；And carry out after acid treatment, than
Surface area further increases, but intensity has declined again.Especially comparative example 3, its intensity is substantially reduced, this
It is because that not adding cobalt element in the carrier preparation process has directly carried out acid treatment.
The preparation of corresponding silver catalyst in comparative example 1-3 and embodiment 1-6
700g silver nitrate is dissolved in 750mL deionized waters silver nitrate solution is obtained；325g ammonium oxalate is dissolved in
Ammonium oxalate solution is obtained in the deionized water that 50 DEG C of 250mL；With vigorous stirring by silver nitrate solution and ammonium oxalate
Solution uniformly mixes, and generates white silver oxalate precipitate；After the aging 1h of silver oxalate precipitate, filter, and spend
Ion water washing filter cake is until without nitrate ion in filtrate, be obtained paste silver oxalate filter cake, the filter cake for being obtained
In contain argent about 60% (weight), aqueous about 15% (weight).
300g ethylenediamines, 110g ethanolamine and 375g deionized waters are added in the glass flask of band stirring, is obtained
To mixed solution.Obtained silver oxalate paste is slowly added in mixed liquor under stirring, temperature is maintained at -5 DEG C
To 10 DEG C, silver oxalate is all dissolved, be subsequently adding 2.2g cesium sulfates and 1.4g strontium acetates, then add deionization
Water makes solution gross mass reach 2000g, by resulting solution mix homogeneously, obtains silver catalyst impregnation liquid, is obtained
The silver content of the silver compound impregnation liquid for obtaining is 22% (weight).
The each 15g of obtained support samples in comparative example 1-3 and embodiment 1-6 is taken, the appearance of vacuum-pumping is respectively placed in
In device, vacuum being evacuated to less than 10mmHg, being added thereto to above-mentioned silver catalyst impregnation liquid, submergence is carried
Body, keeps 30min.Leaching afterwards removes unnecessary silver catalyst impregnation liquid, by the carrier after dipping at 350 DEG C
Air stream in heat 5min, cool down, comparative example 1-3 is prepared respectively and the corresponding silver of embodiment 1-6 is urged
Agent.Obtained silver catalyst is named as into CZ-1 to CZ-9, to the silver in obtained silver catalyst and helping
The content (wherein content is in terms of metal) of agent is analyzed, in CZ-1 to CZ-9 silver and auxiliary agent (caesium and
Strontium) content it is essentially identical, the content of wherein silver element is about 16.1% (weight).And use minisize reaction
Device evaluating apparatus determine its activity and selectivity, and the temperature and selective data when reaction proceeds to the 8th day is listed in
In table 3.
The physical parameter of the catalyst of table 3
| Catalyst source | Catalyst | Initial reaction temperature (DEG C) | EO (mol%) | Selectivity (%) |
| Comparative example 1 | CZ-1 | 227 | 2.51 | 83.02 |
| Comparative example 2 | CZ-2 | 222.5 | 2.50 | 84.07 |
| Comparative example 3 | CZ-3 | 228.1 | 2.50 | 83.23 |
| Embodiment 1 | CZ-4 | 223.8 | 2.50 | 84.77 |
| Embodiment 2 | CZ-5 | 223.0 | 2.51 | 84.19 |
| Embodiment 3 | CZ-6 | 225.9 | 2.51 | 85.10 |
| Embodiment 4 | CZ-7 | 223.9 | 2.49 | 84.89 |
| Embodiment 5 | CZ-8 | 223.2 | 2.50 | 84.24 |
| Embodiment 6 | CZ-9 | 224 | 2.51 | 84.88 |
By data in table 3 it is known that its load according to made by the modified alpha-alumina supports of present invention offer
Silver catalyst, be applied to oxidation of ethylene production reacting ethylene oxide during, be conducive to chain carrier
Catalyst (CZ-1 prepared by the carrier (without cobalt element) in dispersion, with comparative example 1 and comparative example 3
With CZ-3) to compare, selectivity of catalyst and activity are significantly improved；(contain cobalt element with the carrier of comparative example 2
But without acid compound process) prepare catalyst (CZ-2) compare, its selectivity is improved significantly.
It should be noted that embodiment described above is only used for explaining the present invention, do not constitute to the present invention's
Any restriction.By referring to exemplary embodiments, invention has been described, it should be appreciated that wherein used
Word is descriptive and explanatory vocabulary, rather than limited vocabulary.Can be by regulation in the claims in the present invention
In the range of the present invention is modified, and the present invention is carried out in without departing substantially from scope and spirit of the present invention
Revision.Although the present invention described in it is related to specific method, material and embodiment, it is not intended that
The present invention is limited to wherein disclosed particular case, conversely, the present invention to can be extended to other all with identical function
Methods and applications.
Claims (12)
1. a kind of modified alpha-alumina supports, it is obtained by alpha-alumina supports containing cobalt through acid solution process.
2. modified alpha-alumina supports according to claim 1, it is characterised in that the α containing cobalt-oxygen
Change alumina supporter to be obtained by the precursor mixture Jing molding of alpha-alumina supports containing cobalt, drying and roasting, wherein, it is described
The precursor mixture of alpha-alumina supports containing cobalt is included：
Component a, three water A12O3；
Component b, false water A12O3；
Component d, mineralizer；
Component e, cobalt simple substance and/or cobalt compound；
Component f, binding agent；
Component g, water；And it is optional
Component c, weight alkaline earth metal compound.
3. modified alpha-alumina supports according to claim 2, it is characterised in that the α containing cobalt-oxygen
The composition for changing alumina supporter precursor mixture by solid constituent a-e gross weight meter is as follows：
4. modified alpha-alumina supports according to claim 3, it is characterised in that the α containing cobalt-oxygen
The composition for changing alumina supporter precursor mixture by solid constituent a-e gross weight meter is as follows：
5. modified alpha-alumina supports according to any one in claim 2-4, it is characterised in that
The mineralizer is fluoride；
The cobalt compound includes at least in cobalt oxide, cobalt carbonate, cobalt nitrate, cobaltous chloride and cobaltous sulfate
Kind；It is preferred that the cobalt compound is cobalt oxide and/or cobalt nitrate.
6. a kind of preparation method of the modified alpha-alumina supports as described in any one in claim 1-5,
It includes：
Step A, by the mixing of component a-g, is obtained the precursor mixture of alpha-alumina supports containing cobalt；
Step B, will contain cobalt alpha-alumina supports precursor mixture molding, and be dried, roasting, be obtained α containing cobalt-
Alumina support；
Step C, will contain cobalt alpha-alumina supports carries out the prepared modified alpha-alumina support precursor of acid solution process；
Step D, is washed to modified alpha-alumina support precursor, is dried and roasting, and modified alpha-oxidation is obtained
Alumina supporter；
Wherein, in step C, using acid compound aqueous solution to alpha-alumina supports containing cobalt carry out acid solution
Process.
7. preparation method according to claim 6, it is characterised in that the acid compound it is water-soluble
The hydrogen ion concentration of liquid is 0.01-4mol/L；It is preferred that the hydrogen ion concentration of the aqueous solution of the acid compound is
0.05-1.5mol/L。
8. preparation method according to claim 6, it is characterised in that in step C, the α containing cobalt-
Alumina support is 1 with the weight ratio of the aqueous solution of the acid compound:(1-150)；It is preferred that the α containing cobalt-
Alumina support is 1 with the weight ratio of the aqueous solution of the acid compound:(20-60).
9. the preparation method according to any one in claim 6-8, it is characterised in that the acidification
Compound includes mineral acid and/or Acidic inorganic salts, wherein the mineral acid includes sulphuric acid, nitric acid, hydrochloric acid and oxalic acid
At least one of；The Acidic inorganic salts include ammonium nitrate and/or ammonium chloride.
10. the preparation method according to any one in claim 6-9, it is characterised in that in step C
In, the temperature that the acid solution is processed is 20-200 DEG C；It is preferred that the temperature that the acid solution is processed is 40-100 DEG C；Institute
The time for stating acid solution process is 0.2-3h；It is preferred that the time that the acid solution is processed is 0.5-1.5h.
11. a kind of silver catalysts, comprising the modified alpha-carrying alumina as described in any one in claim 1-5
Modified alpha-alumina supports and be carried on that in body or such as claim 6-10 prepared by any one methods described
Silver-colored simple substance in the modified alpha-alumina supports.
12. modified alpha-alumina supports as described in any one in claim 1-5, such as claim 6-10
Modified alpha-alumina supports or silver catalyst as claimed in claim 11 prepared by middle any one methods described
Application during oxidation of ethylene produces oxirane.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109821530A (en) * | 2017-11-23 | 2019-05-31 | 中国科学院大连化学物理研究所 | A kind of cobalt-base catalyst and its method for propylene ring oxidation reaction |
| CN116639958A (en) * | 2023-05-23 | 2023-08-25 | 南充三环电子有限公司 | Alumina powder and preparation method and application thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1511633A (en) * | 2002-12-31 | 2004-07-14 | 中国石油化工股份有限公司北京燕山分 | Carrier for producing silver catalyst for epoxy ethane production, its preparing method and use |
| CN102441435A (en) * | 2010-09-30 | 2012-05-09 | 中国石油化工股份有限公司 | Method for preparing alumina carrier for silver catalyst, carrier prepared by using method and application thereof |
| CN104437665A (en) * | 2013-09-16 | 2015-03-25 | 中国石油化工股份有限公司 | Silver catalyst alpha-alumina carrier preparation method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1511633A (en) * | 2002-12-31 | 2004-07-14 | 中国石油化工股份有限公司北京燕山分 | Carrier for producing silver catalyst for epoxy ethane production, its preparing method and use |
| CN102441435A (en) * | 2010-09-30 | 2012-05-09 | 中国石油化工股份有限公司 | Method for preparing alumina carrier for silver catalyst, carrier prepared by using method and application thereof |
| CN104437665A (en) * | 2013-09-16 | 2015-03-25 | 中国石油化工股份有限公司 | Silver catalyst alpha-alumina carrier preparation method |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109821530A (en) * | 2017-11-23 | 2019-05-31 | 中国科学院大连化学物理研究所 | A kind of cobalt-base catalyst and its method for propylene ring oxidation reaction |
| CN116639958A (en) * | 2023-05-23 | 2023-08-25 | 南充三环电子有限公司 | Alumina powder and preparation method and application thereof |
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