CN112547053B - Methane oxidative coupling catalyst and preparation method and application thereof - Google Patents

Methane oxidative coupling catalyst and preparation method and application thereof Download PDF

Info

Publication number
CN112547053B
CN112547053B CN202110069467.1A CN202110069467A CN112547053B CN 112547053 B CN112547053 B CN 112547053B CN 202110069467 A CN202110069467 A CN 202110069467A CN 112547053 B CN112547053 B CN 112547053B
Authority
CN
China
Prior art keywords
stirring
sio
oxidative coupling
carrier
mass
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110069467.1A
Other languages
Chinese (zh)
Other versions
CN112547053A (en
Inventor
李德宝
林明桂
刘俊义
牛鹏宇
马军祥
张力
贾丽涛
崔艳斌
余海兵
李莉
栗鑫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanxi Lu'an Chemical Co.,Ltd.
Shanxi Institute of Coal Chemistry of CAS
Original Assignee
Shanxi Institute of Coal Chemistry of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanxi Institute of Coal Chemistry of CAS filed Critical Shanxi Institute of Coal Chemistry of CAS
Priority to CN202110069467.1A priority Critical patent/CN112547053B/en
Publication of CN112547053A publication Critical patent/CN112547053A/en
Application granted granted Critical
Publication of CN112547053B publication Critical patent/CN112547053B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/32—Manganese, technetium or rhenium
    • B01J23/34—Manganese
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2/00—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms
    • C07C2/76—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by condensation of hydrocarbons with partial elimination of hydrogen
    • C07C2/82—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by condensation of hydrocarbons with partial elimination of hydrogen oxidative coupling
    • C07C2/84—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by condensation of hydrocarbons with partial elimination of hydrogen oxidative coupling catalytic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2523/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00
    • C07C2523/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • C07C2523/32—Manganese, technetium or rhenium
    • C07C2523/34—Manganese
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Catalysts (AREA)

Abstract

The invention relates to the field of a core-shell composite carrier loaded transition metal methane oxidative coupling catalyst, in particular to a methane oxidative coupling catalyst, which is prepared from WO3And MnO2As an active component, adding an alkali metal additive M on the basis of the active component, and loading the alkali metal additive M and the active component on a carrier SiO2@Al2O3The composition of the catalyst is M-WO3‑MnO2/SiO2@Al2O3. The invention also relates to a preparation method and application of the catalyst. Compared with the conventional catalyst, the catalyst has low activation temperature and good heat resistance, and can perform methane oxidative coupling reaction in a wider range.

Description

Methane oxidative coupling catalyst and preparation method and application thereof
Technical Field
The invention belongs to a core-shell composite carrier loaded transition metal methane oxidative coupling catalyst, a preparation method and application conditions thereof.
Background
The technology for preparing ethylene from natural gas comprises two routes of indirect conversion and direct conversion. The indirect conversion comprises the methanol to ethylene (MTO) of natural gas, Fischer-TropschA line-to-line ethylene production technology (FTO), and the like; the direct conversion comprises methane anaerobic dehydrogenation technology (MDA), methane oxidative coupling ethylene preparation technology (OCM) and the like. The indirect methane conversion process is complex, and the methane needs to be converted into synthesis gas at high temperature, and then the synthesis gas is subjected to one-step or two-step method to synthesize the ethylene. From the energy point of view, the indirect conversion needs to completely break the C-H bonds which should be partially remained in the product to generate synthesis gas, and then hydrocarbon products are obtained by recombination under the action of a catalyst, so that great waste on energy is caused. The direct conversion of methane has been regarded by the industry and scholars because of the simple process, among which, the anaerobic dehydrogenation technique is difficult to activate methane, the reaction usually requires a high temperature above 1000 ℃, and the products are mainly aromatic hydrocarbons and a small amount of C2 +A hydrocarbon; the reaction temperature for preparing ethylene by Oxidative Coupling (OCM) is relatively low, the important industrial raw material ethylene is taken as a main product, the industrial prospect is wide, and the method is always in a generally good technical route. Although various types of methane-activating catalysts have been developed since the first report of this process in the last 80 th century, the performance of these catalysts has a significant gap from commercial demand. Of these catalysts, the silica-supported sodium tungsten manganese system catalyst exhibits good performance in comparison with other system catalysts, CH4Conversion, C2The hydrocarbon selectivity and yield have significant advantages and are considered to be one of the most potential methane oxidative coupling catalysts. However, the sodium tungsten manganese system catalyst has insufficient stability, mainly because: (1) the silica crystal phase transformation affects the interaction with the active component; (2) the sintering and loss of the active components lead to the weakening of the synergistic effect among the components and the reduction of the performance. The key point for solving the problems is to inhibit the crystal transformation of silicon dioxide and the loss of components and improve the heat resistance of the catalyst. For this reason, researchers have endeavored to find suitable solutions to achieve high yields while extending the useful life of the catalyst.
CN1389293A discloses a catalyst for preparing ethylene by methane pressure oxidative coupling using silicon dioxide as a carrier, which can obtain 33.0% of methane conversion rate and 24.1% of C under the pressure condition2 +The yield was found. CN101385982A disclosesNa is loaded by taking mesoporous material SBA-15 as carrier2WO4And Mn, methane conversion of 30.19%, C under the preferred conditions2 +The hydrocarbon selectivity was 60.43%. CN103657640A discloses a supported catalyst using barium titanate as a carrier, C2 +The hydrocarbon yield can reach 24%. Although these catalysts exhibit good performance, the mutual fusion of the components is not yet tight enough, and the crystal transformation phenomenon of the carrier silica is also serious, so that the catalysts have poor heat resistance and poor stability, and are still unfavorable factors for industrial application.
Disclosure of Invention
The invention aims to provide a method for preparing C by oxidative coupling of methane2+A hydrocarbon supported multicomponent transition metal catalyst, a preparation method and an application thereof, which solve the problems of the catalyst.
The technical scheme adopted by the invention is as follows: a methane oxidative coupling catalyst, which is prepared from WO3And MnO2As an active component, adding an alkali metal additive M on the basis of the active component, and loading the alkali metal additive M and the active component on a carrier SiO2@Al2O3The composition of the catalyst is M-WO3-MnO2/SiO2@Al2O3。
The alkali metal additive M is one of Li, Na and K.
Active ingredient WO32.0-20.0% by mass of the carrier, MnO2The mass of the composite carrier is 1.0-10.0% of the mass of the carrier, the mass of the alkali metal additive is 0.1-10.0% of the mass of the carrier, and the mass of the composite carrier is SiO2@Al2O3The mass ratio of the medium silicon dioxide to the alumina is 1: 0.19 to 3.4.
A preparation method of a methane oxidative coupling catalyst comprises the following steps:
(1) mixing alumina and absolute ethyl alcohol according to a mass ratio of 1: 10-100, uniformly stirring, adjusting the pH value to 8.0-10.0 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 10-120 minutes, and then mixing the components in a molar ratio of TEOS: al (Al)2O3= 1: 1-10 portions of tetraethoxysilane are added, and the mixture is continuously stirred for 30 to120 minutes; repeating the steps for 5-20 times, washing the obtained sample to be neutral by using absolute ethyl alcohol, drying, and roasting at 500-800 ℃ for 1-12 hours to obtain SiO with a core-shell structure2@Al2O3A carrier;
(2) mixing a surfactant, a cosurfactant and an oil phase according to a mass ratio of 2-4: 1: 1-0.5, and uniformly stirring to form an oil phase solution A.
(3) Soluble tungsten-containing salt and manganese salt are mixed according to the mass ratio W: mn = 1: dissolving the mixture in deionized water in a ratio of 0.05-5, stirring the mixture uniformly, and adding citric acid to ensure that the total molar ratio of the citric acid to metal atoms is 3-20: 1, stirring the mixture evenly to form a mixed solution B;
(4) dropwise adding the mixed solution B into the oil phase solution A obtained in the step (2) at the speed of 2-20 mL/min, stirring while dropwise adding, and after stirring uniformly, adding the SiO obtained in the step (1)2@Al2O3The carrier is stirred to be uniform to form a microemulsion system;
(5) additionally preparing 0.1-1.0 mol/L alkaline solution, and then dropwise adding the solution to the microemulsion system formed in the step (4) until the pH value is 8.0-11.0;
(6) aging the sample obtained in the step (5) at 25-80 ℃ for 1-24 hours, separating the sample for 5-30 minutes by a centrifuge of 1000-5000 r/min, washing the sample with absolute ethyl alcohol until no obvious oil phase and surfactant exist on the surface of the precipitate, and washing the precipitate with distilled water until the precipitate is neutral;
(7) dissolving soluble alkali metal salt in distilled water with the same volume as the precipitate obtained in the step (6), adding the precipitate obtained in the step (6), stirring into paste, drying, and roasting at 700-900 ℃ for 1-12 hours to obtain M-WO3-MnO2/SiO2@Al2O3A catalyst.
The alumina in the step (1) is activated alumina with the particle size within the range of 5-150 nanometers.
SiO of core-shell structure in step (1)2@Al2O3The carrier is active alumina with the surface coating thickness of 1 within the range of 5-150 nanometers.A composite carrier formed by a 0-10.0 nm silicon dioxide layer.
The surfactant in the step (2) is one of cetyl trimethyl ammonium bromide CTAB, dioctadecyl dimethyl ammonium chloride DODMAC, polyethylene glycol octyl phenyl ether Triton X-100, dioctyl sodium sulfosuccinate AOT, sodium dodecyl sulfate SDS, sodium dodecyl benzene sulfonate DBS and lauryl polyoxyethylene sodium sulfate AES.
The cosurfactant in the step (2) is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decyl alcohol and n-dodecyl alcohol.
The oil phase in the step (2) is one of hexane, heptane, octane, cyclohexane, cycloheptane or cyclooctane.
And (4) the soluble tungsten-containing salt in the step (3) is one of sodium tungstate, potassium tungstate or ammonium tungstate.
The soluble manganese salt in the step (3) is one of manganese nitrate, manganese acetate, manganese chloride or manganese sulfate.
And (5) the alkaline solution is one of sodium carbonate, potassium carbonate or ammonia water.
The soluble alkali metal salt in the step (7) is soluble salt of one of Li, Na and K.
Application of methane oxidative coupling catalyst in preparation of C through oxidative coupling of methane2+Hydrocarbon reaction, reaction feed gas CH4/O2The ratio is 10.0-2.0, the reaction pressure is normal pressure, the reaction temperature is 700-900 ℃, and the airspeed of the reaction gas is 5000-100000 mL-g-1·h-1。
Compared with the prior art, the invention has the following advantages:
(1) the active component WO can be prepared by adopting a preparation method combining sol-gel and microemulsion3And MnO2The contact at the atomic level is beneficial to the mutual cooperation among atoms and improves the performance of the catalyst; on the other hand, the active component and the silicon dioxide are more tightly acted, the loss and sintering of the active phase are delayed, and the service life of the catalyst is prolonged.
(2) Benefit toSiO with core-shell structure formed by supporting silicon dioxide with alumina2@Al2O3On one hand, the alumina can stabilize the structure of the silicon dioxide and inhibit the crystal transformation of the silicon dioxide; on the other hand, the core-shell structure can avoid the exposure of acid sites to alumina and prevent C2Secondary oxidation of hydrocarbons.
(3) Compared with the prior conventional catalyst, the M-WO prepared by adopting the combined method3-MnO2/SiO2@Al2O3The catalyst has low activation temperature and good heat resistance, and can perform methane oxidative coupling reaction in a wider range.
Detailed Description
The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
Example 1:
mixing activated alumina with the particle size of 5nm and absolute ethyl alcohol according to the mass ratio of 1: 100, uniformly stirring, adjusting the pH value to 8.0 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 10 minutes, and then mixing the components according to the weight ratio of TEOS: al (Al)2O3= 1: 10 (molar ratio), adding tetraethoxysilane, and continuing stirring for 30 minutes; the tetraethyl orthosilicate coating step is repeated for 5 times. Washing the obtained sample with absolute ethyl alcohol to be neutral, drying, and roasting at 500 ℃ for 12 hours to obtain SiO with a core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 2.5 nm, SiO2With Al2O3The mass ratio of (1): 3.2. and mixing a surfactant CTAB, a cosurfactant n-butanol and oil phase hexane according to the weight ratio of 2: 1: 1 (mass ratio), and uniformly stirring to form an oil phase solution; taking sodium tungstate and manganese nitrate according to WO3：MnO2= 1: 0.05 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 3: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into the oil phase solution at a speed of 2mL/min while stirring, and after stirring uniformly, adding into a solvent according to WO3And MnO2The SiO obtained above was added in an amount of 20.0% and 1.0% relative to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. And (3) preparing 0.1mol/L sodium carbonate solution, and then dropwise adding the solution to the microemulsion system until the pH value is 8.0. The obtained sample is aged for 24 hours at 25 ℃, separated for 30 minutes by a centrifuge of 1000r/min, washed by absolute ethyl alcohol until no obvious oil phase and surface active agent exist on the surface of the precipitate, and then washed by distilled water until the precipitate is neutral. Lithium nitrate is made to correspond to SiO2@Al2O3Dissolving 0.1% (by metal atom mass) of the carrier in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 700 deg.C for 12 hr to obtain Li-WO3-MnO2/SiO2@Al2O3A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 2.0, the reaction pressure is normal pressure, the reaction temperature is 850 ℃, and the space velocity is 5000mL g-1·h-1. The reaction results are shown in Table 1.
Example 2:
mixing activated alumina with the particle size of 20nm and absolute ethyl alcohol according to the mass ratio of 1: 50, uniformly stirring, adjusting the pH value to 8.5 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 30 minutes, and then mixing the components according to the weight ratio of TEOS: al (Al)2O3= 1: 10 (molar ratio), adding tetraethoxysilane, and continuing stirring for 60 minutes; the tetraethyl orthosilicate coating step was repeated 20 times. Washing the obtained sample with absolute ethyl alcohol to be neutral, drying, and roasting at 600 ℃ for 6 hours to obtain SiO with a core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 5.5 nm, SiO2With Al2O3The mass ratio of (1): 0.9. and adding surfactant DODMAC, cosurfactant n-amyl alcohol and oil phase heptane according to the weight ratio of 3: 1: 0.75 (mass ratio), and uniformly stirring to form an oil phase solution; taking potassium tungstate and manganese acetate according to WO3：MnO2= 1: 0.1 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 5: 1 (molar ratio) adding citric acid, stirring uniformly and shapingForming a mixed solution; dripping the solution into the oil phase solution at a speed of 4mL/min while stirring, and after stirring uniformly, adding into a solvent according to WO3And MnO2The SiO obtained above was added in an amount of 20.0% and 2.0% relative to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. And (3) preparing 0.2mol/L potassium carbonate solution, and then dropwise adding the solution to the microemulsion system until the pH value is 9.0. The obtained sample is aged for 12 hours at 40 ℃, separated for 20 minutes by a 2000r/min centrifugal machine, washed by absolute ethyl alcohol until no obvious oil phase and surface active agent exist on the surface of the precipitate, and then washed by distilled water until the precipitate is neutral. Sodium nitrate is added to SiO2@Al2O3Dissolving 0.5% (by metal atom mass) of the carrier in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 750 deg.C for 8 hr to obtain Na-WO3-MnO2/SiO2@Al2O3A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 3.0, the reaction pressure is normal pressure, the reaction temperature is 800 ℃, and the space velocity is 8000mL g-1·h-1. The reaction results are shown in Table 1.
Example 3:
mixing activated alumina with the particle size of 20nm and absolute ethyl alcohol according to the mass ratio of 1: 50, uniformly stirring, adjusting the pH value to 9.0 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 60 minutes, and then mixing the components according to the weight ratio of TEOS: al (Al)2O3= 1: 5 (molar ratio), adding tetraethoxysilane, and continuing stirring for 60 minutes; the tetraethyl orthosilicate coating step was repeated 10 times. Washing the obtained sample with absolute ethyl alcohol to be neutral, drying, and roasting at 700 ℃ for 3 hours to obtain SiO with a core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 4.9 nm, SiO2With Al2O3The mass ratio of (1): 0.88. and adding surfactant Triton X-100, cosurfactant n-hexanol and oil phase octane according to the weight ratio of 3: 1: 0.8 (mass ratio), and uniformly stirring to form an oil phase solutionLiquid; taking potassium tungstate and manganese acetate according to WO3：MnO2= 1: 0.5 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 10: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into oil phase solution at a rate of 5mL/min while stirring, and stirring uniformly according to WO3And MnO2The SiO obtained above was added in an amount of 10.0% and 5.0% relative to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. 0.5mol/L ammonia water is prepared, and then the mixture is dripped into the microemulsion system until the pH value is 9.5. The obtained sample is aged for 12 hours at 50 ℃, is separated for 20 minutes by a centrifuge with 3000r/min, is washed by absolute ethyl alcohol until no obvious oil phase and surface active agent exist on the surface of the precipitate, and is washed by distilled water until the precipitate is neutral. Relative to SiO to potassium nitrate2@Al2O3Dissolving 1.0% (by metal atom mass) of the carrier in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 800 deg.C for 6 hr to obtain K-WO3-MnO2/SiO2@Al2O3A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 5.0, the reaction pressure is normal pressure, the reaction temperature is 800 ℃, and the space velocity is 20000 mL-g-1·h-1. The reaction results are shown in Table 1.
Example 4:
mixing activated alumina with the particle size of 50nm and absolute ethyl alcohol according to the mass ratio of 1: 20, uniformly stirring, adjusting the pH value to 9.5 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 60 minutes, and then mixing the components according to the weight ratio of TEOS: al (Al)2O3= 1: 4 (molar ratio), adding tetraethoxysilane, and continuing stirring for 90 minutes; the tetraethyl orthosilicate coating step was repeated 10 times. Washing the obtained sample with absolute ethyl alcohol to neutrality, drying, and roasting at 750 ℃ for 2 hours to obtain SiO with a core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 3.0 nm, SiO2With Al2O3The mass ratio of (1): 0.7. and adding a surfactant AOT, a cosurfactant n-heptanol and oil-phase cyclohexane according to the weight ratio of 4: 1: 0.5 (mass ratio), and uniformly stirring to form an oil phase solution; taking ammonium tungstate and manganese chloride according to WO3：MnO2= 1: 1 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 10: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into oil phase solution at a rate of 10mL/min while stirring, and stirring uniformly according to WO3And MnO2SiO obtained as described above was added in an amount of 5.0% and 5.0% with respect to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. 1mol/L ammonia water is prepared, and then the ammonia water is dripped into the microemulsion system until the pH value is 10.0. The obtained sample is aged for 10 hours at 60 ℃, is separated for 10 minutes by a centrifuge with 3000r/min, is washed by absolute ethyl alcohol until no obvious oil phase and surface active agent exist on the surface of the precipitate, and is washed by distilled water until the precipitate is neutral. Lithium acetate is made to correspond to SiO2@Al2O3Dissolving 0.2% of the carrier (calculated by metal atom mass) in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 800 deg.C for 3 hr to obtain Li-WO3-MnO2/SiO2@Al2O3A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 8.0, the reaction pressure is normal pressure, the reaction temperature is 750 ℃, and the space velocity is 50000mL g-1·h-1. The reaction results are shown in Table 1.
Example 5:
mixing active alumina with the particle size of 60nm and absolute ethyl alcohol according to the mass ratio of 1: 100, uniformly stirring, adjusting the pH value to 10.0 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 120 minutes, and then mixing the components according to the weight ratio of TEOS: al (Al)2O3= 1: 6 (molar ratio), adding tetraethoxysilane, and continuing stirring for 90 minutes; the tetraethyl orthosilicate coating step is repeated for 8 times. Anhydrous ethyl ester for obtained sampleWashing with alcohol to neutrality, drying, and calcining at 800 deg.C for 1 hr to obtain SiO with core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 1.6 nm, SiO2With Al2O3The mass ratio of (1): 1.3. and adding a surfactant SDS, a cosurfactant n-octanol and an oil phase cycloheptane into the mixture according to the weight ratio of 4: 1: 0.6 (mass ratio), and uniformly stirring to form an oil phase solution; taking ammonium tungstate and manganese sulfate according to WO3：MnO2= 1: 2 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the mixture is stirred according to the following ratio of citric acid: total metal atoms = 20: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into the oil phase solution at a rate of 20mL/min while stirring, and stirring uniformly according to WO3And MnO2The SiO obtained above was added in an amount of 3.0% and 6.0% relative to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. And preparing 1mol/L sodium carbonate solution, and then dropwise adding the solution to the microemulsion system until the pH value is 10.0. Aging the obtained sample at 80 deg.C for 3 hr, centrifuging at 5000r/min for 5min, washing with anhydrous ethanol until no obvious oil phase and surfactant are on the surface of precipitate, and washing with distilled water to neutrality. Sodium acetate is made to correspond to SiO2@Al2O3Dissolving 0.75% (by metal atom mass) of the carrier in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 850 deg.C for 2 hr to obtain Na-WO3-MnO2/SiO2@Al2O3A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 2.5, the reaction pressure is normal pressure, the reaction temperature is 700 ℃, and the space velocity is 30000mL g-1·h-1. The reaction results are shown in Table 1.
Example 6:
mixing active alumina with the particle size of 100nm and absolute ethyl alcohol according to the mass ratio of 1: 100, stirring uniformly, adjusting the pH value to 10.0 by using ammonia water, and continuously stirring until the components are dispersed uniformlyAfter homogenization, sonication was carried out for 120 minutes, and then the ratio of TEOS: al (Al)2O3= 1: 2 (molar ratio), adding tetraethoxysilane, and continuing stirring for 120 minutes; the tetraethyl orthosilicate coating step was repeated 20 times. Washing the obtained sample with absolute ethyl alcohol to be neutral, drying, and roasting at 800 ℃ for 1 hour to obtain SiO with a core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 10.0 nm, SiO2With Al2O3The mass ratio of (1): 0.19. and mixing surfactant DBS, cosurfactant n-decyl alcohol and oil phase cyclooctane according to the weight ratio of 3.6: 1: 0.7 (mass ratio), and uniformly stirring to form an oil phase solution; taking ammonium tungstate and manganese nitrate according to WO3：MnO2= 1: 5 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 20: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into oil phase solution at a rate of 10mL/min while stirring, and stirring uniformly according to WO3And MnO2The SiO obtained above was added at 2.0% and 10.0% with respect to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. And (3) preparing 0.5mol/L potassium carbonate solution, and then dropwise adding the solution to the microemulsion system until the pH value is 11.0. Aging the obtained sample at 80 deg.C for 1 hr, centrifuging at 5000r/min for 5min, washing with anhydrous ethanol until no obvious oil phase and surfactant are on the surface of precipitate, and washing with distilled water to neutrality. Relative to SiO, potassium acetate2@Al2O3Dissolving 5% of carrier (calculated by metal atom mass) in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 900 deg.C for 1 hr to obtain K-WO3-MnO2/SiO2@Al2O3A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 12.0, the reaction pressure is normal pressure, the reaction temperature is 900 ℃, and the space velocity is 60000 mL-g-1·h-1. The reaction results are shown in Table 1.
Example 7:
mixing active alumina with the particle size of 10nm and absolute ethyl alcohol according to the mass ratio of 1: 10, uniformly stirring, adjusting the pH value to 8.5 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 20 minutes, and then mixing the components according to the weight ratio of TEOS: al (Al)2O3= 1: 2 (molar ratio), adding tetraethoxysilane, and continuing stirring for 30 minutes; the tetraethyl orthosilicate coating step is repeated for 15 times. Washing the obtained sample with absolute ethyl alcohol to be neutral, drying, and roasting at 600 ℃ for 6 hours to obtain SiO with a core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 6.2 nm, SiO2With Al2O3The mass ratio of (1): 0.24. and mixing surfactant AES, cosurfactant n-dodecanol and oil-phase hexane according to the weight ratio of 2: 1: 1 (mass ratio), and uniformly stirring to form an oil phase solution; taking sodium tungstate and manganese acetate according to WO3：MnO2= 1: 0.3 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 6: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into the oil phase solution at a speed of 4mL/min while stirring, and after stirring uniformly, adding into a solvent according to WO3And MnO2SiO obtained as described above was added in an amount of 5.0% and 1.5% relative to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. And (3) preparing 0.5mol/L potassium carbonate solution, and then dropwise adding the solution to the microemulsion system until the pH value is 9.0. The obtained sample is aged for 6 hours at 40 ℃, is separated for 10 minutes by a 2500r/min centrifuge, is washed by absolute ethyl alcohol until no obvious oil phase and surfactant exist on the surface of the precipitate, and is washed by distilled water until the precipitate is neutral. Sodium nitrate is added to SiO2@Al2O3Dissolving 0.75% (by metal atom mass) of the carrier in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 800 deg.C for 3 hr to obtain Na-WO3-MnO2/SiO2@Al2O3A catalyst. The methane oxidative coupling reaction is carried out on a fixed bed quartz tube reactorIs carried out under the reaction condition of CH4/O2The volume ratio is 3.0, the reaction pressure is normal pressure, the reaction temperature is 800 ℃, and the space velocity is 8000mL g-1·h-1. The reaction results are shown in Table 1.
Example 8:
mixing active alumina with the particle size of 10nm and absolute ethyl alcohol according to the mass ratio of 1: 20, uniformly stirring, adjusting the pH value to 9.0 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 60 minutes, and then mixing the components according to the weight ratio of TEOS: al (Al)2O3= 1: 5 (molar ratio), adding tetraethoxysilane, and continuing stirring for 60 minutes; the tetraethyl orthosilicate coating step is repeated for 15 times. Washing the obtained sample with absolute ethyl alcohol to neutrality, drying, and roasting at 700 ℃ for 4 hours to obtain SiO with a core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 5.1 nm, SiO2With Al2O3The mass ratio of (1): 0.58. and mixing a surfactant CTAB, a cosurfactant n-butanol and oil phase heptane according to the weight ratio of 3.6: 1: 0.7 (mass ratio), and uniformly stirring to form an oil phase solution; taking ammonium tungstate and manganese sulfate according to WO3：MnO2= 1: 0.3 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 6: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into oil phase solution at a rate of 3mL/min while stirring, and stirring uniformly according to WO3And MnO2SiO obtained as described above was added in an amount of 5.0% and 1.5% relative to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. And (3) preparing 0.5mol/L sodium carbonate solution, and then dropwise adding the solution to the microemulsion system until the pH value is 9.5. The obtained sample is aged for 6 hours at 60 ℃, is separated for 10 minutes by a 2500r/min centrifuge, is washed by absolute ethyl alcohol until no obvious oil phase and surfactant exist on the surface of the precipitate, and is washed by distilled water until the precipitate is neutral. Sodium acetate is made to correspond to SiO2@Al2O3Dissolving 1.0% (by mass of metal atom) of the carrier in distilled water of the same volume as the precipitate, adding the obtained precipitate, andstirring into paste, drying, and calcining at 850 deg.C for 3 hr to obtain Na-WO3-MnO2/SiO2@Al2O3A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 3.0, the reaction pressure is normal pressure, the reaction temperature is 800 ℃, and the space velocity is 8000mL g-1·h-1. The reaction results are shown in Table 1.
Example 9:
mixing active alumina with the particle size of 60nm and absolute ethyl alcohol according to the mass ratio of 1: 60, uniformly stirring, adjusting the pH value to 9.5 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 90 minutes, and then mixing the components according to the weight ratio of TEOS: al (Al)2O3= 1: 1 (molar ratio), adding tetraethoxysilane, and continuing stirring for 120 minutes; the tetraethyl orthosilicate coating step is repeated for 5 times. Washing the obtained sample with absolute ethyl alcohol to be neutral, drying, and roasting at 550 ℃ for 9 hours to obtain SiO with a core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 4.8 nm, SiO2With Al2O3The mass ratio of (1): 0.35. and adding surfactant DODMAC, cosurfactant n-amyl alcohol and oil phase octane according to the weight ratio of 4: 1: 1 (mass ratio), and uniformly stirring to form an oil phase solution; taking potassium tungstate and manganese nitrate according to WO3：MnO2= 1: 1 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 5: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into oil phase solution at a rate of 5mL/min while stirring, and stirring uniformly according to WO3And MnO2The SiO obtained above was added in an amount of 10.0% and 10.0% relative to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. 0.1mol/L ammonia water is prepared, and then the mixture is dripped into the microemulsion system until the pH value is 10.0. Aging the obtained sample at 50 deg.C for 12 hr, centrifuging at 3000r/min for 10min, washing with anhydrous ethanol until the precipitate has no obvious oil phase and surfactant on the surface, and washing with distilled waterTo neutral. Sodium nitrate is added to SiO2@Al2O3Dissolving 10.0% (by metal atom mass) of the carrier in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 800 deg.C for 6 hr to obtain Na-WO3-MnO2/SiO2@Al2O3A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 8.0, the reaction pressure is normal pressure, the reaction temperature is 850 ℃, and the space velocity is 100000 mL-g-1·h-1. The reaction results are shown in Table 1.
Example 10:
mixing activated alumina with the particle size of 150nm and absolute ethyl alcohol according to the mass ratio of 1: 100, uniformly stirring, adjusting the pH value to 9.5 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 120 minutes, and then mixing the components according to the weight ratio of TEOS: al (Al)2O3= 1: 10 (molar ratio), adding tetraethoxysilane, and continuing stirring for 120 minutes; the tetraethyl orthosilicate coating step is repeated for 5 times. Washing the obtained sample with absolute ethyl alcohol to be neutral, drying, and roasting at 550 ℃ for 6 hours to obtain SiO with a core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 1.0 nm, SiO2With Al2O3The mass ratio of (1): 3.4. and adding surfactant Triton X-100, cosurfactant hexanol and oil-phase cyclohexane according to the weight ratio of 3: 1: 1 (mass ratio), and uniformly stirring to form an oil phase solution; taking sodium tungstate and manganese nitrate according to WO3：MnO2= 1: 0.5 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 3: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into oil phase solution at a rate of 3mL/min while stirring, and stirring uniformly according to WO3And MnO2The SiO obtained above was added at 2.0% and 1.0% with respect to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. 0.5mol/L ammonia water is prepared and then is dripped into the micro-scale catalystEmulsion system until pH 8.0. The obtained sample is aged for 24 hours at 20 ℃, separated for 5 minutes by a centrifuge with the speed of 5000r/min, washed by absolute ethyl alcohol until no obvious oil phase and surface active agent exist on the surface of the precipitate, and then washed by distilled water until the precipitate is neutral. Sodium acetate is made to correspond to SiO2@Al2O3Dissolving 10.0% (by metal atom mass) of the carrier in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 850 deg.C for 4 hr to obtain Na-WO3-MnO2/SiO2@Al2O3A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 3.0, the reaction pressure is normal pressure, the reaction temperature is 800 ℃, and the space velocity is 8000mL g-1·h-1. The reaction results are shown in Table 1.
Example 11:
mixing active alumina with the particle size of 100nm and absolute ethyl alcohol according to the mass ratio of 1: 100, uniformly stirring, adjusting the pH value to 9.0 by using ammonia water, continuously stirring until the pH value is uniformly dispersed, performing ultrasonic treatment for 100 minutes, and then mixing the components according to the weight ratio of TEOS: al (Al)2O3= 1: 8 (molar ratio), adding tetraethoxysilane, and continuing stirring for 100 minutes; the tetraethyl orthosilicate coating step was repeated 10 times. Washing the obtained sample with absolute ethyl alcohol to neutrality, drying, and roasting at 650 ℃ for 4 hours to obtain SiO with a core-shell structure2@Al2O3The carrier and the characterization result show that SiO is contained2The thickness of the layer is about 1.8 nm, SiO2With Al2O3The mass ratio of (1): 1.5. and adding a surfactant AOT, a cosurfactant n-heptanol and an oil phase cycloheptane into the mixture according to the weight ratio of 3: 1: 0.8 (mass ratio), and uniformly stirring to form an oil phase solution; taking potassium tungstate and manganese chloride according to WO3：MnO2= 1: 0.2 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 10: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into oil phase solution at a rate of 10mL/min while stirring, and stirring uniformly according to WO3And MnO2The SiO obtained above was added in an amount of 10.0% and 2.0% relative to the mass of the support2@Al2O3And stirring uniformly to form a microemulsion system. 1.0mol/L ammonia water is prepared, and then the mixture is dripped into the microemulsion system until the pH value is 9.0. The obtained sample is aged for 24 hours at 20 ℃, separated for 5 minutes by a centrifuge with the speed of 5000r/min, washed by absolute ethyl alcohol until no obvious oil phase and surface active agent exist on the surface of the precipitate, and then washed by distilled water until the precipitate is neutral. Relative to SiO to potassium nitrate2@Al2O3Dissolving 2.0% (by metal atom mass) of the carrier in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 850 deg.C for 4 hr to obtain K-WO3-MnO2/SiO2@Al2O3A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 3.0, the reaction pressure is normal pressure, the reaction temperature is 850 ℃, and the space velocity is 10000mL g-1·h-1. The reaction results are shown in Table 1.
Comparative example 1:
mixing a surfactant, a cosurfactant and an oil phase according to the weight ratio of 3.6: 1: 0.7 (mass ratio), and uniformly stirring to form an oil phase solution; taking ammonium tungstate and manganese nitrate according to WO3：MnO2= 1: 0.3 (mass ratio) is dissolved in deionized water, and after the mixture is stirred to be uniform, the weight ratio of citric acid: total metal atoms = 6: 1 (molar ratio) adding citric acid, and uniformly stirring to form a mixed solution; dripping the solution into oil phase solution at a rate of 3mL/min while stirring, and stirring uniformly according to WO3And MnO2Adding silicon dioxide with particle size of 10nm into the carrier with a mass ratio of 5.0% and 1.5%, and stirring to obtain microemulsion system. And (3) preparing 0.5mol/L sodium carbonate solution, and then dropwise adding the solution to the microemulsion system until the pH value is 9.5. The obtained sample is aged for 6 hours at 60 ℃, is separated for 10 minutes by a 2500r/min centrifuge, is washed by absolute ethyl alcohol until no obvious oil phase and surfactant exist on the surface of the precipitate, and is washed by distilled water until the precipitate is neutral. Sodium acetate relative to SiO2@Al2O3Dissolving 1.0% (by metal atom mass) of the carrier in distilled water with the same volume as the precipitate, adding the obtained precipitate, stirring to obtain paste, drying, and roasting at 850 deg.C for 3 hr to obtain Na-WO3-MnO2/SiO2A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 3.0, the reaction pressure is normal pressure, the reaction temperature is 800 ℃, and the space velocity is 8000mL g-1·h-1. The reaction results are shown in Table 1.
Comparative example 2:
dissolving manganese nitrate in a certain amount of deionized water to ensure that MnO is2Impregnating 60-80 mesh silica in equal volume relative to the weight of the carrier of 1.5%, drying, and adding ammonium tungstate according to WO3：MnO2= 1: dissolving 0.3 (corresponding oxide mass ratio) in a certain amount of deionized water, soaking the obtained sample twice in equal volume, drying, soaking the twice-soaked sample again in equal volume with sodium acetate according to 1.0% (by metal atom mass) of the carrier mass, drying, and roasting at 850 deg.C for 3 hr to obtain Na-WO prepared by soaking method3-MnO2/SiO2A catalyst. The oxidative coupling reaction of methane is carried out on a fixed bed quartz tube reactor under the reaction condition of CH4/O2The volume ratio is 3.0, the reaction pressure is normal pressure, the reaction temperature is 800 ℃, and the space velocity is 8000mL g-1·h-1. The reaction results are shown in Table 1.
TABLE 1 results of catalyst reaction evaluation
Figure DEST_PATH_IMAGE001
*Containing 3% or less of C3And the above hydrocarbons, the same as below.
As shown in the table, the supported multi-component transition metal catalyst prepared by the method of combining the sol-gel and the microemulsion shows excellent reaction performance, and CH (methyl) is adopted under the optimal conditions4The conversion rate was 36.2%,C2hydrocarbon selectivity 68.3%, C2+The hydrocarbon yield can reach 24.7% (example 8, 800 ℃); the support of comparative example 1 contains only silica and no alumina and performs similarly to the catalyst of example 8, whereas the catalyst of comparative example 2, prepared by impregnation, performs significantly less than the catalyst provided by the present invention.
The stability differences between the preferred catalysts provided by the present invention and the catalysts of comparative example 1 were compared by reaction performance evaluation, and the results are shown in table 2.
TABLE 2 evaluation results of preferred catalyst stability
Figure 370678DEST_PATH_IMAGE002
Reaction conditions are as follows: the temperature is 800 ℃, and the space velocity is 8000h-1，CH4/O2=3.0
As shown in the above table, the catalyst provided by the present invention has good stability performance due to the inhibition effect of alumina on silica transcrystallization, compared with the catalyst containing no alumina in comparative example 1, and the performance does not change significantly in 200 hours on-line.

Claims (10)

1. A methane oxidative coupling catalyst characterized by: with WO3And MnO2As an active component, adding an alkali metal additive M on the basis of the active component, and loading the alkali metal additive M and the active component on a carrier SiO2@Al2O3The composition of the catalyst is M-WO3-MnO2/SiO2@Al2O3The alkali metal additive M is one of Li, Na and K, and an active component WO32.0-20.0% by mass of the carrier, MnO2The mass of the composite carrier is 1.0-10.0% of the mass of the carrier, the mass of the alkali metal additive is 0.1-10.0% of the mass of the carrier, and the mass of the composite carrier is SiO2@Al2O3The mass ratio of the medium silicon dioxide to the alumina is 1: 0.19 to 3.4, and the preparation method of the methane oxidative coupling catalyst comprises the following steps:
(1) mixing alumina and absolute ethyl alcohol according to a mass ratio of 1: 10 to 100Mixing the components according to the proportion, adjusting the pH value to 8.0-10.0 by using ammonia water after uniformly stirring, continuously stirring until the mixture is uniformly dispersed, performing ultrasonic treatment for 10-120 minutes, and then mixing the components according to the molar ratio of TEOS: al (Al)2O3= 1: adding tetraethoxysilane into the mixture according to the proportion of 1-10, and continuously stirring the mixture for 30-120 minutes; repeating the steps for 5-20 times, washing the obtained sample to be neutral by using absolute ethyl alcohol, drying, and roasting at 500-800 ℃ for 1-12 hours to obtain SiO with a core-shell structure2@Al2O3A carrier;
(2) mixing a surfactant, a cosurfactant and an oil phase according to a mass ratio of 2-4: 1: 1-0.5, and uniformly stirring to form an oil phase solution A;
(3) soluble tungsten-containing salt and manganese salt are mixed according to the mass ratio W: mn = 1: dissolving the mixture in deionized water in a ratio of 0.05-5, stirring the mixture uniformly, and adding citric acid to ensure that the total molar ratio of the citric acid to metal atoms is 3-20: 1, stirring the mixture evenly to form a mixed solution B;
(4) dropwise adding the mixed solution B into the oil phase solution A obtained in the step (2) at the speed of 2-20 mL/min, stirring while dropwise adding, and after stirring uniformly, adding the SiO obtained in the step (1)2@Al2O3The carrier is stirred to be uniform to form a microemulsion system;
(5) additionally preparing 0.1-1.0 mol/L alkaline solution, and then dropwise adding the solution to the microemulsion system formed in the step (4) until the pH value is 8.0-11.0;
(6) aging the sample obtained in the step (5) at 25-80 ℃ for 1-24 hours, separating the sample for 5-30 minutes by a centrifuge of 1000-5000 r/min, washing the sample with absolute ethyl alcohol until no obvious oil phase and surfactant exist on the surface of the precipitate, and washing the precipitate with distilled water until the precipitate is neutral;
(7) dissolving soluble alkali metal salt in distilled water with the same volume as the precipitate obtained in the step (6), adding the precipitate obtained in the step (6), stirring into paste, drying, and roasting at 700-900 ℃ for 1-12 hours to obtain M-WO3-MnO2/SiO2@Al2O3A catalyst.
2. A methane oxidative coupling catalyst according to claim 1, wherein: the alumina in the step (1) is activated alumina with the particle size within the range of 5-150 nanometers.
3. The process for preparing a methane oxidative coupling catalyst according to claim 1, wherein: SiO of core-shell structure in step (1)2@Al2O3The carrier is a composite carrier formed by coating a silicon dioxide layer with the thickness of 1.0-10.0 nanometers on the surface of active aluminum oxide within the range of 5-150 nanometers.
4. A methane oxidative coupling catalyst according to claim 1, wherein: the surfactant in the step (2) is one of cetyl trimethyl ammonium bromide CTAB, dioctadecyl dimethyl ammonium chloride DODMAC, polyethylene glycol octyl phenyl ether Triton X-100, dioctyl sodium sulfosuccinate AOT, sodium dodecyl sulfate SDS, sodium dodecyl benzene sulfonate DBS and lauryl polyoxyethylene sodium sulfate AES.
5. A methane oxidative coupling catalyst according to claim 1, wherein: the cosurfactant in the step (2) is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decyl alcohol and n-dodecyl alcohol.
6. A methane oxidative coupling catalyst according to claim 1, wherein: the oil phase in the step (2) is one of hexane, heptane, octane, cyclohexane, cycloheptane or cyclooctane.
7. A methane oxidative coupling catalyst according to claim 1, wherein: and (4) the soluble tungsten-containing salt in the step (3) is one of sodium tungstate, potassium tungstate or ammonium tungstate.
8. A methane oxidative coupling catalyst according to claim 1, wherein: the soluble manganese salt in the step (3) is one of manganese nitrate, manganese acetate, manganese chloride or manganese sulfate.
9. A methane oxidative coupling catalyst according to claim 1, wherein: and (5) the alkaline solution is one of sodium carbonate, potassium carbonate or ammonia water.
10. Use of an oxidative coupling catalyst with methane according to claim 1, wherein: for preparing C by oxidative coupling of methane2+Hydrocarbon reaction, reaction feed gas CH4/O2The ratio is 10.0-2.0, the reaction pressure is normal pressure, the reaction temperature is 700-900 ℃, and the airspeed of the reaction gas is 5000-100000 mL-g-1·h-1。
CN202110069467.1A 2021-01-19 2021-01-19 Methane oxidative coupling catalyst and preparation method and application thereof Active CN112547053B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110069467.1A CN112547053B (en) 2021-01-19 2021-01-19 Methane oxidative coupling catalyst and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110069467.1A CN112547053B (en) 2021-01-19 2021-01-19 Methane oxidative coupling catalyst and preparation method and application thereof

Publications (2)

Publication Number Publication Date
CN112547053A CN112547053A (en) 2021-03-26
CN112547053B true CN112547053B (en) 2021-09-14

Family

ID=75035667

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110069467.1A Active CN112547053B (en) 2021-01-19 2021-01-19 Methane oxidative coupling catalyst and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN112547053B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113617363B (en) * 2021-08-30 2023-03-17 武汉强丰新特科技有限公司 Supported multi-metal oxide catalyst and preparation method and application thereof
CN114905186A (en) * 2022-04-15 2022-08-16 哈尔滨工业大学 SiO with inertia 2 Preparation method and application of negative expansion particles of protective layer
CN114956940B (en) * 2022-05-30 2024-05-14 昆明理工大学 Method for converting methane into ethylene and acetylene with assistance of low-temperature plasma

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103418429A (en) * 2012-05-16 2013-12-04 中国石油化工股份有限公司 Methane oxygen-free dehydrogenation aromatization catalyst and preparation method thereof
CN104447316A (en) * 2013-09-24 2015-03-25 中国石油化工股份有限公司 Preparation method for preparing ethylidene diacetate from methyl acetate
CN108067264A (en) * 2016-11-11 2018-05-25 中国石油化工股份有限公司抚顺石油化工研究院 A kind of methane reforming catalyst and its preparation method and application

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103418429A (en) * 2012-05-16 2013-12-04 中国石油化工股份有限公司 Methane oxygen-free dehydrogenation aromatization catalyst and preparation method thereof
CN104447316A (en) * 2013-09-24 2015-03-25 中国石油化工股份有限公司 Preparation method for preparing ethylidene diacetate from methyl acetate
CN108067264A (en) * 2016-11-11 2018-05-25 中国石油化工股份有限公司抚顺石油化工研究院 A kind of methane reforming catalyst and its preparation method and application

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"Phase States of Li(Na,K,Rb,Cs)/W/Mn/SiO2 Composite Catalysts for Oxidative Coupling of Methane";G. D. Nipan et al;《Russian Journal of Inorganic Chemistry》;20161231;第61卷(第14期);第1689-1707页 *

Also Published As

Publication number Publication date
CN112547053A (en) 2021-03-26

Similar Documents

Publication Publication Date Title
CN112547053B (en) Methane oxidative coupling catalyst and preparation method and application thereof
CN108238846B (en) Preparation method of catalyst for ethanol synthesis, catalyst obtained by preparation method and application of catalyst
CN102463136B (en) Core-shell structure MFI molecular sieve and its preparation method
CN108178164B (en) Hierarchical porous ZSM-5 molecular sieve, preparation method thereof and method for preparing PX catalyst by using same
KR20130082273A (en) Catalyst for oxidative coupling reaction of methane, method for preparing the same, and method for oxidative coupling reaction of methane using the same
CN101767036A (en) Titanium silicalite TS-1 catalyst preparation method
JPH0231056B2 (en)
CN105523569A (en) Lamellar ZSM-5 molecular sieve and synthesis method thereof
EP3558869B1 (en) Process to convert synthesis gas to olefins using a bifunctional chromium / zinc oxide-sapo-34 catalyst
CN102285669B (en) Method for preparing SAPO-34 molecular sieve with rich Si(4Al) structures and product and application thereof
CN113318774B (en) Modified Co-based catalyst, preparation method and application thereof, and method for preparing propylene by propane anaerobic dehydrogenation
CN111375444A (en) Core-shell iron-based catalyst for directly producing aromatic hydrocarbon from synthesis gas and preparation method and application thereof
CN114029070A (en) In-situ hydrogenolysis aryl ether bond catalyst and preparation method and application thereof
CN108722408B (en) Catalyst for synthesizing ethylene glycol by dimethyl oxalate gas phase hydrogenation and preparation method thereof
CN108772061B (en) Solid acid catalyst for isomerization reaction and n-butane-isobutane isomerization method
CN113058643A (en) Modified TS-1 molecular sieve composite catalyst and preparation method and application thereof
CN109876804B (en) Titanium dioxide loaded ruthenium catalyst for preparing cyclohexene through selective hydrogenation of benzene and preparation method thereof
CN112547054B (en) Supported methane oxidative coupling catalyst and preparation method and application thereof
CN108816227B (en) Metal frame derived supported copper-based catalyst and preparation method thereof
CN102861604B (en) Olefin catalytic agent prepared by naphtha catalytic cracking and preparation method and application thereof
CN114425396A (en) Supported non-noble metal catalyst, preparation method and application thereof, and low-carbon alkane dehydrogenation method
CN106582806B (en) To be hydrated modified aluminas as the method for matrix fabricated in situ SAPO-11@γ-Al2O3 composite carrier
CN108671935B (en) Preparation method and application of surface acidity-enhanced supported copper-based catalyst
Zhang et al. Synergistic catalysis of nano-Pd and nano rare-earth oxide/AC: complex nanostructured catalysts fabricated by a photochemical route for selective hydrogenation of phenol
CN110694679A (en) EMT/FAU core-shell molecular sieve catalyst and preparation method and application thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20220315

Address after: 046200 Wangqiao Industrial Park, Xiangyuan County, Changzhi City, Shanxi Province

Patentee after: Shanxi Lu'an Chemical Co.,Ltd.

Patentee after: Shanxi Institute of coal chemistry, Chinese Academy of Sciences

Address before: 030001 No. 27 Taoyuan South Road, Shanxi, Taiyuan

Patentee before: INSTITUTE OF COAL CHEMISTRY, CHINESE ACADEMY OF SCIENCES

TR01 Transfer of patent right