CN114308043A - Preparation method of acidified two-dimensional layered vermiculite supported nickel-based catalyst - Google Patents
Preparation method of acidified two-dimensional layered vermiculite supported nickel-based catalyst Download PDFInfo
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- 239000003054 catalyst Substances 0.000 title claims abstract description 108
- 239000010455 vermiculite Substances 0.000 title claims abstract description 76
- 229910052902 vermiculite Inorganic materials 0.000 title claims abstract description 76
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- 238000002360 preparation method Methods 0.000 title claims abstract description 19
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- 238000000034 method Methods 0.000 claims abstract description 26
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- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
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- 239000012298 atmosphere Substances 0.000 claims description 10
- 239000001257 hydrogen Substances 0.000 claims description 10
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- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 5
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- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 abstract description 2
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- SCPYDCQAZCOKTP-UHFFFAOYSA-N silanol Chemical compound [SiH3]O SCPYDCQAZCOKTP-UHFFFAOYSA-N 0.000 description 2
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- KDRIEERWEFJUSB-UHFFFAOYSA-N carbon dioxide;methane Chemical compound C.O=C=O KDRIEERWEFJUSB-UHFFFAOYSA-N 0.000 description 1
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- FMQXRRZIHURSLR-UHFFFAOYSA-N dioxido(oxo)silane;nickel(2+) Chemical compound [Ni+2].[O-][Si]([O-])=O FMQXRRZIHURSLR-UHFFFAOYSA-N 0.000 description 1
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- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
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- 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
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Abstract
The invention relates to a preparation method of an acidified two-dimensional layered vermiculite supported nickel-based catalyst. The method adopts expanded vermiculite as a carrier, obtains a vermiculite structure without a layered molecular sieve with a large specific surface area by treating in an acid solution, washing and drying, and prepares the acidified two-dimensional layered vermiculite supported nickel-based catalyst by a micro-excess liquid phase high-temperature roasting method. The invention has the advantages of simple catalyst composition, simple and convenient preparation process, easy operation, low production cost and the like, the catalyst prepared without adding an auxiliary agent subsequently has the advantages of uniform dispersion of metal particles, small average particle size, strong sintering resistance and carbon deposition resistance at high temperature and the like, and has good industrial prospect when being applied to the reforming reaction of methane and carbon dioxide to prepare the synthesis gas.
Description
Technical Field
The invention belongs to the technical field of catalyst preparation and environmental protection, and particularly relates to a preparation method of an acidified two-dimensional layered vermiculite supported nickel-based catalyst.
Background
As the greenhouse effect increases, overcoming the effects that global warming may bring has become a global common goal and challenge. Methane and carbon dioxide are used as two greenhouse gases, and the comprehensive conversion and utilization of the methane and the carbon dioxide have important significance for relieving the greenhouse effect. Methane and carbon dioxide reforming reactions (DRM) can utilize these two gases to convert them to H2Syngas in equimolar ratio/CO. The synthesis gas produced by DRM can be used to produce high value-added chemicals using a fischer-tropsch synthesis. According to thermodynamic analysis, DRM is a high temperature endothermic reversible reaction, requiring higher reaction temperatures. Therefore, the catalyst used under such conditions may be deactivated by sintering of the active metal. In addition, during the DRM reaction, side reactions that cause carbon deposition, i.e., methane cracking reaction and carbon monoxide disproportionation reaction, are also accompanied. Therefore, a great deal of research has been devoted to solving these two problems, mainly by using noble metal-supported catalysts. However, in view of the cost of these noble metal catalysts, their industrial application is limited. Therefore, nickel-based catalysts are one of the most favored alternatives to noble metal catalysts due to their abundant nickel reserves, low cost, and high catalytic activity comparable to noble metal catalysts. However, nickel-based catalysts are more susceptible to deactivation during high temperature reactions due to sintering and carbon deposition. The active center of the catalyst is reduced by sintering the active components of the nickel-based catalyst, so that the reaction activity is reduced; in addition, carbon deposition generated in the reaction process of the catalyst covers the active site of the catalyst and blocks the pore channel of the catalyst, thereby influencing the diffusion of reactant and product molecules. Therefore, it is important to improve the sintering resistance and carbon deposition resistance of the catalyst.
Disclosure of Invention
The invention aims to provide a preparation method of an acidified two-dimensional layered vermiculite supported nickel-based catalyst aiming at the defects in the prior art. The method provides a preparation idea from top to bottom, expanded vermiculite is used as a carrier, a vermiculite structure of the layered molecular sieve with a large specific surface area is obtained by treating, washing and drying in an acid solution, and the acidified two-dimensional layered vermiculite supported nickel-based catalyst is prepared by a micro-excess liquid-phase high-temperature roasting method. The invention has the advantages of simple catalyst composition, simple and convenient preparation process, easy operation, low production cost and the like, the catalyst prepared without adding an auxiliary agent subsequently has the advantages of uniform dispersion of metal particles, small average particle size, strong sintering resistance and carbon deposition resistance at high temperature and the like, and has good industrial prospect when being applied to the reforming reaction of methane and carbon dioxide to prepare the synthesis gas.
In order to realize the preparation of the catalyst, the technical scheme of the invention is as follows:
a preparation method of an acidified two-dimensional layered vermiculite supported nickel-based catalyst comprises the following steps:
(1) immersing expanded vermiculite into a hydrochloric acid solution under the condition of stirring, and violently stirring and refluxing for 4-6 hours at the temperature of 60-90 ℃; washing the obtained bright yellow precipitate with deionized water, filtering, and drying to obtain acid-treated vermiculite powder carrier; wherein the concentration of the hydrochloric acid solution is 1-3 mol/L; adding 5-15g of expanded vermiculite into every 200ml of hydrochloric acid solution; the rotation number of the violent stirring is 700-900 rpm;
(2) mixing Ni (NO)3)2Dropwise adding the solution onto a vacuum-dried acid-treated vermiculite powder carrier, drying in the air, and drying at 100-120 ℃ for 6-10 hours to obtain dry powder;
wherein, Ni (NO) is added per 1mL3)2The solution contains 0.06-0.17 g of Ni (NO)3)2·6H2O; dripping 0.5-3 mL of mixed solution into every 1g of acid-treated vermiculite carrier;
the vacuum drying temperature is 60-90 ℃, and the time is 3-5 hours;
(3) heating the dried powder to 500-600 ℃ at the speed of 1-3 ℃/min in the air atmosphere, and roasting for 3-5 h to obtain the catalyst of the acidified two-dimensional layered vermiculite confinement nickel nanoparticles;
the method further comprises the step (4), heating the acidified two-dimensional layered vermiculite supported nickel-based catalyst to 450-550 ℃ in a nitrogen atmosphere, switching the gas to a pure hydrogen atmosphere, and reducing for 1-3 hours;
in the catalyst, the loading amount of nickel is 2.5-7.5 wt%;
the hydrochloric acid treatment concentration of the acidified two-dimensional layered porous vermiculite is 2.5 mol/L.
The water absorption capacity of each 1g of acid-treated vermiculite carrier before impregnation is 2.3mL, and the vacuum drying temperature is 80 ℃.
In the roasting process, the heating rate is 2 ℃/min, the roasting temperature is 550 ℃, and the roasting time in the air atmosphere is 4 h.
In the reduction process, the reduction temperature is 500 ℃, and the reduction time in a pure hydrogen atmosphere is 2 h.
Preferably, in the preparation method of the acidified two-dimensional layered vermiculite supported nickel-based catalyst, the supported amount of nickel in the two-dimensional layered porous catalyst prepared by the slight excess impregnation method is 5 wt%, the catalyst still shows good catalytic activity and stability under the premise of relatively low nickel supported amount, and the nickel particle size is only 3-5 nm, which indicates that the catalyst has good nickel dispersibility.
The application of the preparation method of the acidified two-dimensional layered vermiculite supported nickel-based catalyst prepared by the method is used for catalytically synthesizing carbon monoxide and hydrogen by taking carbon dioxide and methane as raw materials.
The method specifically comprises the following steps: mixing the catalyst and quartz sand, putting the mixture into a fixed bed reactor, and reacting at the temperature of 700 ℃ plus 800 ℃ and the space velocity of 90000-100000 mL h-1gcat -1Then introducing methane, carbon dioxide and nitrogen to obtain carbon monoxide and hydrogen;
wherein, the raw material ratio is methane: carbon dioxide: nitrogen is 1:1: 2.
The invention has the substantive characteristics that:
at present, the improvement of the sintering resistance and the carbon deposition resistance of the nickel-based catalyst becomes a key scientific and technical problem of the dry reforming reaction of methane.
For the problem of catalyst sintering, the preparation method of the nickel-based methane dry reforming catalyst provided by the invention has the advantages that nickel nanoparticles with small size in the obtained nickel-based catalyst are dispersed in a two-dimensional layered vermiculite porous structure with good thermal stability, the carrier is rich in silanol structure, the nickel metal particles are anchored, and the anti-sintering performance of the nickel-based catalyst is improved by utilizing the interaction of strong metal of two-dimensional layered nickel silicate and the carrier. For the problem of carbon deposition resistance, about 2-5 wt% of Fe is left in the acidified porous vermiculite prepared by the invention2O3Can be used as a natural assistant to accelerate the gasification of deposited carbon species, thereby obviously improving the stability and the anti-carbon deposition performance of the catalyst.
The invention has the beneficial effects that:
1. compared with the traditional nickel-based catalyst loaded by silicon dioxide, the catalyst can form a two-dimensional layered porous vermiculite structure. Even if the catalyst is prepared by using a traditional impregnation method, good metal dispersibility and small particle size can be realized due to the confinement effect of the modified carrier. This confinement effect inhibits sintering of the metal nanoparticles under high temperature reactions. Meanwhile, as the carbon deposition reaction is a structure sensitive reaction, the catalyst has strong metal agglomeration resistance and good carbon deposition resistance, and the stability of the catalyst is obviously improved.
2. According to the invention, a hydrochloric acid acidifier is used for preparing the acidified two-dimensional layered vermiculite supported nickel-based catalyst, the acidification concentration is optimized, the vermiculite can obtain the maximum silanol content after being acidified by 2.5mol/L hydrochloric acid, more nickel metal particles can be anchored, the nickel metal particles can be more easily close to the surface of a carrier taking silicon dioxide as a main matrix, and stronger interaction with the carrier is formed in the high-temperature roasting process, so that the stability of the catalyst is improved.
3. After the acidified two-dimensional layered vermiculite supported nickel-based catalyst used in the invention is reacted at a high temperature for 24 hours, the layered porous structure of the catalyst is still maintained, because the structure of the vermiculite is kept unchanged under the high-temperature condition due to the high-temperature stability of the vermiculite, the size of the supported nickel metal particles is almost not increased, and the high-temperature stability of the acidified two-dimensional porous vermiculite supported nickel-based catalyst is shown.
4. The catalyst prepared by the invention is at the high temperature of 750 ℃ and 96000mL h-1g-cat-1The catalyst prepared by the method has good stability and anti-carbon deposition performance.
Drawings
FIG. 1 is an SEM image of two-dimensional exfoliated porous vermiculite obtained in example 1 of the present invention after 2.5mol/L hydrochloric acid treatment.
Fig. 2 is a TEM image of a reduced acidified two-dimensional layered porous vermiculite supported nickel-based catalyst.
Fig. 3 is a particle size statistical plot of nickel metal particles of a reduced acidified two-dimensional layered porous vermiculite supported nickel-based catalyst.
Fig. 4 is a TEM image of the acidified two-dimensional layered porous vermiculite supported nickel based catalyst after 24h reaction.
Fig. 5 is a particle size statistical diagram of nickel metal particles of the acidified two-dimensional layered porous vermiculite supported nickel-based catalyst after 24h reaction.
FIG. 6 is a TG plot of the methane dry reforming nickel-based catalyst obtained in example 1 of the present invention after 24h of reaction.
Detailed Description
To further illustrate the present invention, the present invention will now be described in detail by way of specific embodiments.
Example 1
Preparing acidified two-dimensional layered porous vermiculite: 10g of ball-milled commercial expanded vermiculite (100 meshes) is mixed with 200mL of 2.5mol/L hydrochloric acid solution to prepare suspension with the solid-liquid ratio of 1:20, and 50mL of 36-38% concentrated hydrochloric acid with 2.5mol/L hydrochloric acid is dissolved in 200mL of deionized water to prepare the water-based paint. Stirring and refluxing the suspension vigorously at 80 ℃ at the rotating speed of 800rpm for 4 h; the obtained bright yellow precipitate is filtered and washed by deionized water until the filtrate is neutral, and the obtained solid is dried at 100 ℃ overnight to obtain the vermiculite powder carrier treated by 2.5mol/L hydrochloric acid.
Preparing an acidified two-dimensional layered porous vermiculite supported nickel-based catalyst: 1g of the acid-treated vermiculite powder carrier prepared above was dried under vacuum at 80 ℃ to remove water vapor in the pore channels, and the water absorption was measured. The method comprises the following specific steps: deionized water was added dropwise to the dried vermiculite powder with stirring until the powder became pasty and the water just before it appeared slightly exuded. Stirring at 25 deg.C for 30min until water is evaporated, and drying in vacuum oven at 80 deg.C overnight. The water absorption of the acidified vermiculite was measured to be 2.3 mL/g.
0.25g of Ni (NO)3)2·6H2The O solid was dissolved in 2.3mL of deionized water and the prepared solution was added dropwise to the above dried 1g of acidified vermiculite. And repeating the steps, and drying the naturally dried powder at 100 ℃ overnight to obtain the precursor loaded with the nickelate. Grinding the sample to powder after drying, roasting for 4h at 550 ℃, raising the temperature by 2 ℃ per minute by adopting a programmed temperature, and obtaining a gray product which is NiO-SiO after roasting2An intermediate. The nickel loading of the catalyst prepared was 4.51 wt%.
The catalysts described above were tested for catalytic activity: 25mg (40-60 mesh) of the prepared catalyst was weighed and placed in a fixed bed quartz tube reactor (length 50cm, outer diameter 10mm, inner diameter 6mm, the same as in the following examples) to conduct catalyst performance test. Before testing, the catalyst was reduced in situ using pure hydrogen at 500 ℃ for 2 h. Then, the mixture is replaced by a raw material atmosphere, the sampling amount of methane, carbon dioxide and nitrogen is 1:1:2 (the flow rate is 10mL, 10mL and 20mL), the temperature is 750 ℃, and the space velocity is 96000mL h-1gcat -1Activity tests are carried out, the conversion rates of methane and carbon dioxide of the catalysts are kept about 90% in 24h activity evaluation, and the catalysts after reaction hardly generate carbon deposition.
Example 2
Preparing acidified two-dimensional layered porous vermiculite: 10g of ball-milled commercial expanded vermiculite (100 meshes) is mixed with 200mL of 3mol/L hydrochloric acid solution to prepare suspension with a solid-to-liquid ratio of 1:20, and 50mL of 36-38% concentrated hydrochloric acid with 3mol/L hydrochloric acid is dissolved in 150mL of deionized water to prepare the water-based paint. Stirring and refluxing the suspension vigorously at 80 deg.C for 4 h; the obtained bright yellow precipitate is filtered and washed by deionized water until the filtrate is neutral, and the obtained solid is dried at 100 ℃ overnight to obtain the vermiculite powder carrier after 3mol/L hydrochloric acid treatment.
Preparing an acidified two-dimensional layered porous vermiculite supported nickel-based catalyst: 1g of the acid-treated vermiculite powder carrier prepared above was dried under vacuum at 80 ℃ to remove water vapor in the pore channels, and the water absorption was measured. The method comprises the following specific steps: deionized water was added dropwise to the dried vermiculite powder with stirring until the powder became pasty and the water just before it appeared slightly exuded. Stirring at 25 deg.C for 30min until water is evaporated, and drying in vacuum oven at 80 deg.C overnight. The water absorption of the acidified vermiculite was measured to be 2.8 mL/g.
0.25g of Ni (NO)3)2·6H2The O solid was dissolved in 2.8mL of deionized water and the prepared solution was dropped drop-wise into dry acidified vermiculite. And repeating the steps, and drying the naturally dried powder at 100 ℃ overnight to obtain the precursor loaded with the nickelate. Grinding the sample to powder after drying, roasting for 4h at 550 ℃, raising the temperature by 2 ℃ per minute by adopting a programmed temperature, and obtaining a gray product which is NiO-SiO after roasting2An intermediate. The nickel loading of the catalyst prepared was 4.51 wt%.
The catalysts described above were tested for catalytic activity: 25mg (40-60 meshes) of the prepared catalyst is weighed and placed in a fixed bed quartz tube reactor for catalyst performance test. Before testing, the catalyst was reduced in situ using pure hydrogen at 500 ℃ for 2 h. Then, the mixture is replaced by a raw material atmosphere, the sampling amount of methane, carbon dioxide and nitrogen is 1:1:2 (the flow rate is 10mL, 10mL and 20mL), the temperature is 750 ℃, and the space velocity is 96000mL h-1gcat -1When activity tests are carried out, the conversion rates of the catalysts, namely methane and carbon dioxide, are respectively reduced to about 67 percent and 70 percent. There was a significant drop in activity and a significant sintering was observed, the less reactive than in example 1 probably due to the higher hydrochloric acid concentration making part of the vermiculiteThe porous structure is damaged, and the domain limiting effect of pore canal collapse on the nickel metal particles is weakened, so that the activity is poor.
Example 3
The other steps were the same as in example 1, except that the calcination temperature was changed to 450 ℃. The catalyst activity test conditions were the same as in example 1, and the conversion of methane and carbon dioxide was 64% and 68%, respectively. The catalyst is quickly inactivated at 750 ℃, and the reason for the inactivation is probably that the roasting temperature is too low, and the active center does not form strong interaction with the carrier.
Example 4
The other steps were the same as in example 1, except that the catalyst reduction temperature was changed to 750 ℃. The catalyst activity test conditions were the same as in example 1, and the conversion rates of methane and carbon dioxide were 67% and 70%, respectively. And is rapidly deactivated at a temperature of 750 c, which may be due to an excessively high reduction temperature, so that the metal particles are rapidly sintered.
Example 5
The other steps are the same as in example 1, and the catalyst preparation method is changed to an excess impregnation method. The impregnation comprises the following specific steps: 0.25g of Ni (NO)3)2·6H2Dissolving the O solid in deionized water to prepare 20mL of aqueous solution, adding 1g of acidified vermiculite carrier into the solution, stirring at normal temperature for 3h, and then evaporating to dryness overnight to obtain the precursor loaded with nickelate. The catalyst activity test conditions were the same as in example 1, and the conversion of methane and carbon dioxide was 50% and 53%, respectively. And the catalyst is quickly deactivated at the temperature of 750 ℃, and the reason for the deactivation is probably that the metal particles of the catalyst prepared by an excess impregnation method are large and uneven, so that the exposure of the active specific surface area of the metal is very little, and the metal particles cannot fully play a role.
As can be seen from the above examples, the hydrochloric acid concentration of the acidified two-dimensional layered porous vermiculite supported nickel-based catalyst in example 1 is 2.5mol/L, the hydrochloric acid concentration of the acidified two-dimensional layered porous vermiculite supported nickel-based catalyst in example 2 is 3mol/L, the materials and other operations of the acidified two-dimensional layered porous vermiculite supported nickel-based catalyst are completely the same, and the 2.5mol/L hydrochloric acid acidified catalyst shows excellent catalytic performance of methane dry reforming and enhanced anti-sintering and anti-carbon deposition performance, while the 3mol/L hydrochloric acid acidified catalytic performance shows excellent catalytic performance of methane dry reforming and enhanced anti-sintering and anti-carbon deposition performanceThe acidification concentration of the agent is too high, so that the pore channel structure of the porous vermiculite is partially collapsed, and the domain limiting effect on nickel metal particles is partially lost, so that the catalytic stability of the catalyst is reduced, and the problem of metal sintering in the reaction process is solved; next, on the basis of treating the porous vermiculite supported nickel-based catalyst with 2.5mol/L hydrochloric acid, examples 3 and 4 respectively reduce and increase the roasting and reduction temperatures of the catalyst, which both show poor catalyst performance of methane dry reforming, and show that the appropriate roasting temperature can realize maximization of interaction between metal carriers, the appropriate reduction temperature can completely reduce nickel particles on the basis of reducing the sintering condition of the catalyst, and the catalytic stability and anti-carbon deposition performance of the methane carbon dioxide dry reforming reaction are obviously improved. The domain limiting effect of the acidified two-dimensional porous vermiculite coating and the anchoring effect of silanol on metal particles are proved, and the anti-sintering performance of the nickel-based catalyst is improved. For the problem of carbon deposition resistance, a proper amount of hydrochloric acid is used for modification to obtain a proper amount of Fe2O3As an auxiliary agent, the catalyst accelerates the gasification of deposited carbon, thereby obviously improving the carbon deposition resistance of the catalyst.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
The invention is not the best known technology.
Claims (9)
1. A preparation method of an acidified two-dimensional layered vermiculite supported nickel-based catalyst is characterized by comprising the following steps:
(1) immersing expanded vermiculite into a hydrochloric acid solution under the condition of stirring, and violently stirring and refluxing for 4-6 hours at the temperature of 60-90 ℃; washing the obtained bright yellow precipitate with deionized water, filtering, and drying to obtain acid-treated vermiculite powder carrier;
wherein the concentration of the hydrochloric acid solution is 1-3 mol/L;
(2) mixing Ni (NO)3)2Dropping the solution into the vacuumDrying the air-dried vermiculite powder carrier on an acid-treated vermiculite powder carrier at 100-120 ℃ for 6-10 hours to obtain dry powder;
wherein, Ni (NO) is added per 1mL3)2The solution contains 0.06-0.17 g of Ni (NO)3)2·6H2O; dripping 0.5-3 mL of mixed solution into every 1g of acid-treated vermiculite carrier;
(3) and heating the dried powder to 500-600 ℃ in an air atmosphere, and roasting for 3-5 h to obtain the catalyst of the acidified two-dimensional layered vermiculite confined nickel nanoparticles.
2. The preparation method of the acidified two-dimensional layered vermiculite supported nickel-based catalyst according to claim 1, characterized in that the method further comprises the step (4), the acidified two-dimensional layered vermiculite supported nickel-based catalyst is heated to 450-550 ℃ in a nitrogen atmosphere, and then the gas is switched to a pure hydrogen atmosphere to be reduced for 1-3 hours.
3. The method for preparing the acidified two-dimensional layered vermiculite supported nickel-based catalyst according to claim 1, wherein the supported amount of nickel in the catalyst is 2.5-7.5 wt%.
4. The method for preparing the acidified two-dimensional exfoliated vermiculite-supported nickel-based catalyst according to claim 1, wherein in the step (1), preferably 5 to 15g of expanded vermiculite is added to every 200ml of hydrochloric acid solution; the rotation number of the violent stirring is 700-900 rpm; the vacuum drying temperature in the step (2) is 60-90 ℃, and the time is 3-5 hours; the heating rate in the step (3) is 1-3 ℃/min.
5. The method for preparing the acidified two-dimensional exfoliated vermiculite-supported nickel-based catalyst according to claim 1, wherein the hydrochloric acid treatment concentration of the acidified two-dimensional exfoliated porous vermiculite in the step (1) is 2.5 mol/L;
before impregnation, the water absorption capacity of each 1g of acid-treated vermiculite carrier is 2.3mL, and the vacuum drying temperature is 80 ℃;
in the roasting process, the heating rate is 2 ℃/min, the roasting temperature is 550 ℃, and the roasting time in the air atmosphere is 4 h;
in the reduction process, the reduction temperature is 500 ℃, and the reduction time in a pure hydrogen atmosphere is 2 h.
6. The method of claim 1, wherein the catalyst is prepared by a slight excess impregnation method.
7. The method for preparing the acidified two-dimensional layered vermiculite supported nickel-based catalyst according to claim 1, wherein the loading amount of nickel is 5 wt%, and the particle size of nickel is 3-5 nm.
8. The application of the preparation method of the acidified two-dimensional layered vermiculite supported nickel-based catalyst prepared by the method of claim 1 is characterized in that the catalyst is used for catalytically synthesizing carbon monoxide and hydrogen by using carbon dioxide and methane as raw materials.
9. The application of the preparation method of the acidified two-dimensional layered vermiculite supported nickel-based catalyst prepared by the method according to claim 8 is characterized by comprising the following steps: mixing the catalyst and quartz sand, putting the mixture into a fixed bed reactor, and reacting at the temperature of 700 ℃ plus 800 ℃ and the space velocity of 90000-100000 mL h-1gcat -1Then introducing methane, carbon dioxide and nitrogen to obtain carbon monoxide and hydrogen;
wherein, the raw material ratio is methane: carbon dioxide: nitrogen is 1:1: 2.
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| CN103191744A (en) * | 2013-04-17 | 2013-07-10 | 中国科学院新疆理化技术研究所 | Modified vermiculite supported nickel catalyst and preparation method thereof |
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| CN115869941A (en) * | 2022-12-29 | 2023-03-31 | 淮安中顺环保科技有限公司 | Preparation method of two-dimensional layered vermiculite interlayer confinement noble metal nanoparticle catalyst |
| CN115869941B (en) * | 2022-12-29 | 2023-09-05 | 淮安中顺环保科技有限公司 | Preparation method of two-dimensional layered vermiculite interlayer confinement noble metal nanoparticle catalyst |
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