CN111250124A - Preparation method of carrier with composite coating - Google Patents
Preparation method of carrier with composite coating Download PDFInfo
- Publication number
- CN111250124A CN111250124A CN202010133698.XA CN202010133698A CN111250124A CN 111250124 A CN111250124 A CN 111250124A CN 202010133698 A CN202010133698 A CN 202010133698A CN 111250124 A CN111250124 A CN 111250124A
- Authority
- CN
- China
- Prior art keywords
- coating
- carrier
- aluminum
- ceramic
- composite coating
- 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.)
- Pending
Links
- 239000011248 coating agent Substances 0.000 title claims abstract description 179
- 238000000576 coating method Methods 0.000 title claims abstract description 179
- 239000002131 composite material Substances 0.000 title claims abstract description 56
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- 239000000919 ceramic Substances 0.000 claims abstract description 118
- 229910010271 silicon carbide Inorganic materials 0.000 claims abstract description 42
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims abstract description 41
- 239000007788 liquid Substances 0.000 claims abstract description 29
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 claims abstract description 27
- 238000001035 drying Methods 0.000 claims abstract description 23
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 18
- 239000011259 mixed solution Substances 0.000 claims abstract description 18
- 239000000758 substrate Substances 0.000 claims abstract description 16
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 claims abstract description 15
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims abstract description 15
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 12
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 12
- 239000011230 binding agent Substances 0.000 claims abstract description 7
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 claims abstract description 6
- VXAUWWUXCIMFIM-UHFFFAOYSA-M aluminum;oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Al+3] VXAUWWUXCIMFIM-UHFFFAOYSA-M 0.000 claims abstract description 6
- 230000002378 acidificating effect Effects 0.000 claims abstract description 5
- 238000004519 manufacturing process Methods 0.000 claims abstract 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 47
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 35
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 claims description 33
- 239000011159 matrix material Substances 0.000 claims description 29
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 17
- 239000002202 Polyethylene glycol Substances 0.000 claims description 13
- 229920001223 polyethylene glycol Polymers 0.000 claims description 13
- 239000000243 solution Substances 0.000 claims description 12
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 9
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 8
- 239000002253 acid Substances 0.000 claims description 7
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 6
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 claims description 6
- 229910017604 nitric acid Inorganic materials 0.000 claims description 6
- 239000011148 porous material Substances 0.000 claims description 6
- 235000006408 oxalic acid Nutrition 0.000 claims description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 14
- 239000003054 catalyst Substances 0.000 abstract description 11
- 239000000377 silicon dioxide Substances 0.000 abstract description 7
- 238000007664 blowing Methods 0.000 description 13
- 239000012298 atmosphere Substances 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 12
- 238000002156 mixing Methods 0.000 description 12
- 239000011247 coating layer Substances 0.000 description 10
- 108010009736 Protein Hydrolysates Proteins 0.000 description 8
- 229960000583 acetic acid Drugs 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 238000012546 transfer Methods 0.000 description 6
- 238000012360 testing method Methods 0.000 description 5
- 239000002585 base Substances 0.000 description 4
- 239000000413 hydrolysate Substances 0.000 description 4
- 239000000969 carrier Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 239000006260 foam Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- 235000012239 silicon dioxide Nutrition 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 229910010293 ceramic material Inorganic materials 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 229910052878 cordierite Inorganic materials 0.000 description 2
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 239000012876 carrier material Substances 0.000 description 1
- 238000007084 catalytic combustion reaction Methods 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004299 exfoliation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000012362 glacial acetic acid Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000000527 sonication Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000012855 volatile organic compound Substances 0.000 description 1
Images
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
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/20—Carbon compounds
- B01J27/22—Carbides
- B01J27/224—Silicon carbide
-
- 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
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
- B01J35/61—Surface area
- B01J35/613—10-100 m2/g
-
- 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
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
- B01J35/61—Surface area
- B01J35/615—100-500 m2/g
-
- 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
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
- B01J35/64—Pore diameter
- B01J35/647—2-50 nm
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Catalysts (AREA)
Abstract
The application relates to a preparation method of a carrier with a composite coating, and belongs to the technical field of composite coating preparation. A method of making a carrier with a composite coating, comprising: drying and roasting the silicon carbide ceramic substrate with the surface coated with the coating liquid to obtain a ceramic carrier with a first coating on the surface; the coating liquid comprises ethyl orthosilicate and aluminum salt, and is acidic. Drying and roasting the ceramic carrier with the mixed liquid on the surface, and forming a second coating on the surface of the first coating to obtain the ceramic carrier with the composite coating on the surface; the mixed solution comprises an aluminum source and a binder, wherein the aluminum source comprises at least one of aluminum oxide, aluminum hydroxide or pseudo-boehmite. The first coating obtained by the preparation method comprises alumina and silica, the second coating comprises alumina, and the alumina coating can effectively increase the specific surface area of the ceramic carrier to form a carrier with high thermal conductivity and high specific surface area, and is suitable for a structural catalyst carrier.
Description
Technical Field
The application relates to the technical field of composite coating preparation, in particular to a preparation method of a carrier with a composite coating.
Background
At present, alumina, silica, titania, cordierite and the like are used as catalyst carriers, and the carrier materials have the common disadvantage of low thermal conductivity. For strongly exothermic or endothermic reactions and high temperature reactions, low thermal conductivity can result in reaction heat not being removed in time, thereby forming local hot spots that affect catalyst activity and life. For example, cordierite is the most widely used catalyst carrier for catalytic oxidation treatment of VOCs exhaust gas, and according to feedback, the phenomenon of pulverization occurs after the domestic catalytic combustion catalyst is used for a period of time at present, which is not related to the low thermal conductivity characteristic of the carrier.
The silicon carbide porous structure ceramic not only has the characteristics of high temperature resistance, low expansion, oxidation resistance, chemical inertness and the like of ceramic materials, but also has the thermal conductivity higher than that of stainless steel, and the thermal conductivity of the silicon carbide porous structure ceramic is 18-46 times that of aluminum oxide. But the specific surface area of the silicon carbide porous ceramic is very small (< 1 m)2/g) it is necessary to apply a coating layer of high specific surface area to the surface thereof in order to exert the excellent characteristics of silicon carbide.
Disclosure of Invention
In view of the defects of the prior art, the purpose of the embodiments of the present application includes providing a method for preparing a carrier with a composite coating, so as to improve the technical problems of small specific surface area and low bonding strength between the coating and the carrier of the silicon carbide ceramic carrier.
In a first aspect, embodiments of the present application provide a method for preparing a carrier with a composite coating, including: drying and roasting the silicon carbide ceramic substrate with the surface coated with the coating liquid to obtain a ceramic carrier with a first coating on the surface; the coating liquid comprises ethyl orthosilicate and aluminum salt, and is acidic. Drying and roasting the ceramic carrier with the mixed liquid on the surface, and forming a second coating on the surface of the first coating to obtain the ceramic carrier with the composite coating on the surface; the mixed solution comprises an aluminum source and a binder, wherein the aluminum source comprises at least one of aluminum oxide, aluminum hydroxide or pseudo-boehmite.
The carrier with the composite coating is prepared by the preparation method of the carrier with the composite coating, the first coating comprises alumina and silica, and the second coating comprises alumina. The silicon dioxide in the first coating can not only enhance the firmness between the alumina coating and the porous ceramic matrix, but also enhance the stability of the alumina coating. The alumina coating in the second coating can effectively increase the specific surface area of the ceramic carrier, thereby forming a carrier with high thermal conductivity and high specific surface area, and being suitable for a structural catalyst carrier.
In some embodiments of the present application, the mass ratio of the first coating to the silicon carbide ceramic matrix in the ceramic support having the first coating on the surface is 0.5-1g:100 g. The mass ratio enables the first coating and the ceramic substrate to have better bonding strength, and is helpful for ensuring the bonding strength of the composite coating and the ceramic substrate after the second coating is bonded.
In some embodiments of the present application, the mass ratio of the second coating to the silicon carbide ceramic matrix in the ceramic support having the composite coating on the surface is 2-10g:100 g. This quality ratio makes the second coating have certain thickness, can guarantee the bonding strength of second coating, first coating and ceramic base member by the great degree simultaneously, and composite coating's firmness is guaranteed to the great degree.
In some embodiments of the present application, the coating liquid further comprises water, ethanol and acid, and the mass ratio of the ethyl orthosilicate to the water to the ethanol is 1 (0.1-0.5): (1-5). The acid comprises at least one of nitric acid, acetic acid, hydrochloric acid or oxalic acid, and the aluminum salt comprises at least one of aluminum nitrate and aluminum chloride. The molar concentration of the aluminum salt in the coating liquid is 0.3-1.5 mol/L. The aluminum salt is aluminum nitrate, and the mass ratio of ethyl orthosilicate to aluminum nitrate is 1: (3-10). The mass ratio can improve the combination of the coating liquid and the silicon carbide carrier, and the formed first coating contains a proper amount of aluminum.
In some embodiments of the application, the binder is aluminum nitrate, the mixed solution further includes water, and the mass ratio of the aluminum nitrate to the aluminum oxide to the water is 1 (1-3): (2-5). The mass ratio range can ensure that the second coating has a proper amount of alumina, and the specific surface area of the carrier is effectively increased.
In some embodiments of the present application, the mixed solution further includes polyethylene glycol, and the mass ratio of the aluminum nitrate, the aluminum oxide, the water and the polyethylene glycol is 1 (1-3): (2-5): (0.01-0.05).
The polyethylene glycol is used as a pore-forming agent, so that the second coating has a pore structure, the specific surface area of the prepared carrier is improved, and the prepared carrier is favorable for being used as a structural catalyst carrier.
In some embodiments of the present application, the silicon carbide ceramic matrix has a three-dimensional interconnected mesh structure with mesh openings ranging from 0.5mm to 8mm in diameter. The porous structure is provided with three-dimensional communication network channels, so that mass transfer and heat transfer can be enhanced in the radial direction and the axial direction, and meanwhile, the porous structure is provided with lower pressure drop so as to improve the performance of the carrier.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.
FIG. 1 is a surface SEM image of a ceramic substrate provided in an embodiment of the present application;
FIG. 2 is a sectional SEM photograph of a support having a first coating provided in example 3 of the present application;
FIG. 3 is an SEM image of the surface of a composite coating of a carrier provided in example 3 of the present application;
fig. 4 is an SEM image of the surface of the composite coating of the support provided in example 4 of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
The following is a detailed description of a method for preparing a carrier having a composite coating layer according to an embodiment of the present application.
The embodiment of the application provides a preparation method of a carrier with a composite coating, which takes silicon carbide ceramic as a ceramic carrier and comprises the following steps: and drying and roasting the silicon carbide ceramic substrate with the coating liquid coated on the surface to obtain the ceramic carrier with the first coating on the surface. And drying and roasting the ceramic carrier with the mixed solution coated on the surface, and forming a second coating on the surface of the first coating to obtain the ceramic carrier with the composite coating on the surface.
In some embodiments of the present application, the preparing step of the coating liquid includes: mixing water and ethanol, and adjusting pH to 1-5 with acid. Slowly adding tetraethoxysilane into the mixed solution, and standing for 12-24 hours at room temperature to obtain hydrolysate. Adding a certain amount of aluminum salt into the hydrolysate, and preparing the coating solution with a certain molar concentration by using ethanol. The coating liquid is acidic, and aluminum and silicon in the coating liquid are in molecular contact with the ceramic matrix and are combined with the ceramic matrix in a chemical bond through roasting. Further, the acid in the present application includes at least one of nitric acid, acetic acid, hydrochloric acid, or oxalic acid, and the aluminum salt includes at least one of aluminum nitrate and aluminum chloride. Further, in the examples of the present application, the acid is nitric acid, and the aluminum salt is aluminum nitrate.
This application adopts the carborundum pottery to be the ceramic base member, and silicon in the tetraethoxysilane can combine with the silicon on ceramic base member surface, improves the combination firmness between first coating and the carrier. The tetraethoxysilane is hydrolyzed under the acidic condition to generate crosslinking, the coating liquid generates a first coating containing aluminum oxide and silicon dioxide in the roasting process, and the silicon dioxide has cohesiveness and can promote the silicon carbide carrier to be firmly combined with the first coating.
In some embodiments of the present application, in order to improve the bonding between the coating solution and the silicon carbide carrier, and the formed first coating contains a proper amount of aluminum, the mass ratio of the tetraethoxysilane to the water to the ethanol is 1 (0.1-0.5): (1-5), the molar concentration of aluminum salt in the coating liquid is 0.3-1.5mol/L, the aluminum salt is aluminum nitrate, and the mass ratio of ethyl orthosilicate to aluminum nitrate is 1: (3-10). Optionally, the mass ratio of the ethyl orthosilicate to the water to the ethanol is 1:0.1:1, 1:0.1:3, 1:0.1:5, 1:0.2:2, 1:0.1:3, 1:0.5:1 or 1:0.5:5, the molar concentration of the aluminum salt in the coating liquid is 0.3mol/L, 0.5mol/L, 0.6mol/L, 0.7mol/L, 0.9mol/L, 1mol/L, 1.2mol/L, 1.3mol/L or 1.5mol/L, and the mass ratio of the ethyl orthosilicate to the aluminum nitrate is 1:3, 1:5, 1:6, 1:8 or 1: 10.
In some embodiments of the present application, a silicon carbide porous ceramic matrix is used, and the porous structure has three-dimensional connected network channels, which can enhance mass transfer and heat transfer in the radial and axial directions, and at the same time, has a lower pressure drop, so as to improve the performance of the carrier. Further, the mesh has a pore size of 0.5mm to 8mm, optionally, the mesh has a pore size of 0.5mm, 1mm, 1.5mm, 2mm, 3mm, 5mm, 6mm, or 8 mm. It is noted that the surface of the substrate or carrier in the present application includes the surface of the mesh in the porous structure.
And (3) placing the silicon carbide porous ceramic carrier into the coating liquid for soaking for 1-10 minutes, taking out, and blowing or centrifuging by using high-pressure airflow until no blockage exists between the ceramic meshes. Drying in air atmosphere at 150-. In some embodiments of the present application, the mass ratio of the first coating to the silicon carbide ceramic matrix is 0.5-1g:100g, which provides a better bonding strength between the first coating and the ceramic matrix and helps to ensure the bonding strength between the composite coating and the ceramic matrix after the second coating is bonded. Alternatively, the drying temperature may be 150 ℃, 160 ℃ or 170 ℃, the firing temperature may be 550 ℃, 600 ℃, 650 ℃ or 700 ℃, and the firing time may be 1 hour, 2 hours, 3 hours or 4 hours.
After the first coating is prepared, preparing a mixed solution, comprising the following steps: a quantity of aluminum source, binder and water are mixed. The aluminum source comprises at least one of alumina, aluminum hydroxide or pseudoboehmite. In some embodiments of the present application, the binder is aluminum nitrate, the aluminum source is aluminum oxide, that is, aluminum oxide, aluminum nitrate and water are mixed, and further, the mass ratio of aluminum nitrate, aluminum oxide and water is 1 (1-3): (2-5). Optionally, the mass ratio of aluminum nitrate to aluminum oxide to water is 1:1:2, 1:3:5, 1:2:2, 1:2:5, 1:1:4, 1:3:2, or 1:1: 5.
In some embodiments of the present application, the mixed solution further includes a pore-forming agent polyethylene glycol, so that the second coating has a pore structure, which increases the specific surface area of the prepared carrier and facilitates the use of the prepared carrier in a structural catalyst carrier. The mass ratio of the aluminum nitrate to the alumina to the water to the polyethylene glycol is 1 (1-3): (2-5): (0.01-0.05). Alternatively, the mass ratio of aluminum nitrate, aluminum oxide, water, and polyethylene glycol is 1:1:2:0.01, 1:1:2:0.05, 1:2:2:0.02, 1:1:3:0.03, 1:2:4:0.04, 1:3:5:0.05, or 1:2:3: 0.02.
Immersing the ceramic carrier with the first coating on the surface into the mixed solution, standing for 10-30 minutes, taking out, blowing or centrifuging by high-pressure airflow until no blockage exists among meshes of the porous ceramic, drying in an air atmosphere at the temperature of 110-550 ℃, and then roasting for 2-4 hours at the temperature of 400-550 ℃ to form a second coating containing aluminum oxide on the surface of the first coating, thereby obtaining the ceramic carrier with the composite coating on the surface.
In some embodiments of the present application, the mass ratio of the second coating to the silicon carbide ceramic matrix is 2-10g:100 g. This quality ratio makes the second coating have certain thickness, can guarantee the bonding strength of second coating, first coating and ceramic base member by the great degree simultaneously, and composite coating's firmness is guaranteed to the great degree. Optionally, the mass ratio of the second coating to the silicon carbide ceramic matrix is 1g:50g, 3g:100g, 1g:20g, 7g:100g, 8g:100g, or 1g:10 g.
The carrier obtained by the preparation method of the carrier with the composite coating provided by the embodiment of the application has the composite coating, the first coating comprises alumina and silica, the second coating comprises alumina, and the alumina coating can effectively increase the specific surface area of the ceramic carrier to form the carrier with high thermal conductivity and high specific surface area, and is suitable for structural catalyst carriers. The silicon carbide ceramic carrier provided by the application is of a porous structure, and the mass transfer and heat transfer effects of the carrier can be further enhanced through a three-dimensional communication structure.
The features and properties of the present application are described in further detail below with reference to examples.
Example 1
The embodiment provides a preparation method of a carrier with a composite coating, which comprises the following steps:
a silicon carbide ceramic matrix with a mesh aperture of 1mm is used. Mixing quantitative water and ethanol, adjusting pH to 2.5 with nitric acid, slowly adding tetraethoxysilane into the stirred mixed solution, wherein the mass ratio of tetraethoxysilane to water to ethanol is 1:0.1:2, and standing at room temperature for 12 hours to obtain hydrolysate; adding a certain amount of aluminum nitrate into the hydrolysate, and preparing coating liquid with the molar concentration of 0.5mol/L by using ethanol.
And (3) immersing the ceramic matrix in the coating liquid for 8 minutes, taking out, blowing the porous ceramic by high-pressure airflow until no blockage exists among meshes, drying in an air atmosphere at 155 ℃, and roasting at 700 ℃ for 3 hours to obtain the ceramic carrier with the first coating on the surface, wherein the mass ratio of the ceramic carrier to the silicon carbide ceramic matrix is 0.95g:100 g.
Mixing aluminum nitrate, aluminum oxide, water and polyethylene glycol according to a mass ratio of 1:1.5:2:0.05, then immersing the mixture into the ceramic carrier with the first coating on the surface, standing for 30 minutes, taking out, blowing the porous ceramic with high-pressure airflow until no blockage exists among meshes, drying in an air atmosphere at 125 ℃, and roasting at 450 ℃ for 3 hours to obtain a composite coating with a second coating and a ceramic carrier with the composite coating on the surface, wherein the mass ratio of the second coating to the silicon carbide ceramic substrate is 9.7g:100 g.
Example 2
The embodiment provides a preparation method of a carrier with a composite coating, which comprises the following steps:
a silicon carbide ceramic matrix with a mesh aperture of 2.5mm is used. Mixing a certain amount of water and ethanol, adjusting the pH value to 3 by using nitric acid, slowly adding tetraethoxysilane into the stirred mixed solution, and standing for 24 hours at room temperature to obtain hydrolysate, wherein the mass ratio of the tetraethoxysilane to the water to the ethanol is 1:0.1: 3; adding a certain amount of aluminum nitrate into the hydrolysate, and preparing coating liquid with the molar concentration of 0.8mol/L by using ethanol.
And (2) immersing the ceramic matrix in the coating liquid for 6 minutes, taking out, blowing the porous ceramic by high-pressure airflow until no blockage exists among meshes, drying in an air atmosphere at 155 ℃, and roasting at 650 ℃ for 3 hours to obtain the ceramic carrier with the first coating on the surface, wherein the mass ratio of the ceramic carrier to the silicon carbide ceramic matrix is 0.92g:100 g.
Mixing aluminum nitrate, aluminum hydroxide, water and polyethylene glycol according to a mass ratio of 1:2:2:0.05, then immersing the mixture into the ceramic carrier with the first coating on the surface, standing for 25 minutes, taking out, blowing the porous ceramic with high-pressure airflow until no blockage exists among meshes, drying in an air atmosphere at 125 ℃, and roasting at 450 ℃ for 3 hours to obtain a composite coating with a second coating and the ceramic carrier with the composite coating on the surface, wherein the mass ratio of the second coating to the silicon carbide ceramic carrier is 8.5g:100 g.
Example 3
The embodiment provides a preparation method of a carrier with a composite coating, which comprises the following steps:
a silicon carbide ceramic matrix with a mesh aperture of 5.0mm is used. Mixing a certain amount of water and ethanol, adjusting the pH value to 2 by using acetic acid, slowly adding tetraethoxysilane into the stirred mixed solution, and standing for 12 hours at room temperature to obtain hydrolysate, wherein the mass ratio of the tetraethoxysilane to the water to the ethanol is 1:0.1: 3; adding a certain amount of aluminum nitrate into the hydrolysate, and preparing the coating solution with the molar concentration of 1.2mol/L by using ethanol.
And (3) immersing the ceramic matrix in the coating liquid for 3 minutes, taking out, blowing the porous ceramic by high-pressure airflow until no blockage exists among meshes, drying in an air atmosphere at 155 ℃, and roasting at 700 ℃ for 3 hours to obtain the ceramic carrier with the first coating on the surface, wherein the mass ratio of the ceramic carrier to the silicon carbide ceramic matrix is 0.85g:100 g.
Mixing aluminum nitrate, pseudo-boehmite, water and polyethylene glycol according to the mass ratio of 1:2:2.5:0.05, then immersing the mixture into the ceramic carrier with the first coating on the surface, standing for 25 minutes, taking out, blowing the porous ceramic by high-pressure airflow until no blockage exists among meshes, drying in an air atmosphere at 125 ℃, and roasting for 3 hours at 500 ℃ to obtain a composite coating with a second coating and a ceramic carrier with the composite coating on the surface, wherein the mass ratio of the second coating to the silicon carbide ceramic substrate is 9.3g:100 g.
Example 4
The embodiment provides a preparation method of a carrier with a composite coating, which comprises the following steps:
mixing a certain amount of water and ethanol by using a silicon carbide ceramic matrix with a mesh aperture of 5.0mm, adjusting the pH value to 4 by using acetic acid, slowly adding tetraethoxysilane into the stirred mixed solution, wherein the mass ratio of tetraethoxysilane to water to ethanol is 1:0.5:4, and standing at room temperature for 18 hours to obtain hydrolysate; adding a certain amount of aluminum nitrate into the hydrolysate, and preparing coating liquid with the molar concentration of 0.6mol/L by using ethanol.
And (2) immersing the ceramic matrix in the coating liquid for 5 minutes, taking out, blowing the porous ceramic by high-pressure airflow until no blockage exists among meshes, drying in an air atmosphere at 165 ℃, and roasting at 700 ℃ for 3 hours to obtain the ceramic carrier with the first coating on the surface, wherein the mass ratio of the ceramic carrier to the silicon carbide ceramic matrix is 0.65g:100 g.
Mixing aluminum nitrate, aluminum hydroxide, water and polyethylene glycol according to a mass ratio of 1:2.5:5:0.05, then immersing the mixture into the ceramic carrier with the first coating on the surface, standing for 30 minutes, taking out, blowing the porous ceramic with high-pressure airflow until no blockage exists among meshes, drying in an air atmosphere at 120 ℃, and roasting for 3 hours at 500 ℃ to obtain a composite coating with a second coating and a ceramic carrier with the composite coating on the surface, wherein the mass ratio of the second coating to the silicon carbide ceramic substrate is 4.3g:100 g.
Example 5
The embodiment provides a preparation method of a carrier with a composite coating, which comprises the following steps:
mixing a certain amount of water and ethanol by adopting a silicon carbide ceramic matrix with the mesh aperture of 6.5mm, adjusting the pH value to 4 by using acetic acid, slowly adding tetraethoxysilane into the stirred mixed solution, wherein the mass ratio of the tetraethoxysilane to the water to the ethanol is 1:0.4:3, and standing for 15 hours at room temperature to obtain hydrolysate; adding a certain amount of aluminum nitrate into the hydrolysate, and preparing coating liquid with the molar concentration of 0.8mol/L by using ethanol.
And (3) immersing the ceramic substrate in the coating liquid for 4 minutes, taking out, blowing the porous ceramic by high-pressure airflow until no blockage exists among meshes, drying in an air atmosphere at 160 ℃, and roasting at 700 ℃ for 2.5 hours to obtain the ceramic carrier with the first coating on the surface, wherein the mass ratio of the ceramic carrier to the silicon carbide ceramic substrate is 0.57g:100 g.
Mixing aluminum nitrate, pseudo-boehmite, water and polyethylene glycol according to the mass ratio of 1:3:4.5:0.05, then immersing the mixture into the ceramic carrier with the first coating on the surface, standing for 30 minutes, taking out, blowing the porous ceramic until no blockage exists among meshes by using high-pressure airflow, drying in an air atmosphere at 120 ℃, and roasting for 3 hours at 500 ℃ to obtain a composite coating with a second coating and a ceramic carrier with the composite coating on the surface, wherein the mass ratio of the second coating to the silicon carbide ceramic substrate is 6.3g:100 g.
Comparative example 1
The present comparative example provides a catalyst, the method of preparation comprising:
1. taking a proper amount of tetraethoxysilane, water, alcohol, glacial acetic acid and hydrochloric acid, uniformly mixing the other components except the tetraethoxysilane, slowly adding the tetraethoxysilane under the condition of stirring, and standing for 24 hours at the temperature of 25 ℃ to obtain a solution;
2. adding silicon carbide ceramic powder into the solution, stirring the mixture evenly to obtain slurry, making the ceramic material into foam, and firing the foam at high temperature to obtain a foam ceramic carrier;
3. soaking the foamed ceramic in the solution for 5 minutes, taking out, blowing the foamed ceramic by high-pressure airflow until no blockage exists among meshes, uniformly spreading alumina powder on the surface of the foamed ceramic, shaking the foamed ceramic rapidly to uniformly distribute the alumina powder, then placing the foamed ceramic in an environment at 100 ℃ for drying for 3 hours, and after drying, heating to 750 ℃, and keeping the temperature for 1 hour;
4. the foamed ceramic is vacuum soaked in mixed nitrate or acetate solution, stoved at 120 deg.c for 8 hr and roasted at 540 deg.c for 10 hr.
Comparative example 2
This comparative example provides a method for preparing a support, which differs from example 1 only in that:
after the support having the first coating layer was prepared, the second coating layer was not prepared, and a support having only the first coating layer on the surface was obtained.
Comparative example 3
This comparative example provides a method for preparing a support, differing from example 1 only in that:
a carrier having only the second coating layer was prepared without preparing a carrier having the first coating layer, resulting in a carrier having only the second coating layer on the surface.
Test example 1
Scanning electron microscope tests are carried out on the surfaces of the porous ceramic substrates provided in examples 3 and 4 and the prepared carrier with the composite coating, and the results are shown in fig. 1, fig. 2, fig. 3 and fig. 4. As can be seen, a coating layer with the thickness of about 10 μm is formed on the surface of the carrier, and the coating layer is tightly combined with the carrier; after the second coating is applied, a porous, convoluted coating is formed on the surface.
Test example 2
The carriers and the catalysts provided in examples 1 to 5 and comparative examples 1 to 3 were selected and subjected to performance testing analysis, respectively. The BET specific surface area of the coating material was measured by a nitrogen adsorption method using a JW-BK200C model specific surface and pore size analyzer manufactured by Mitsuokbo. The firmness between the carrier and the coating is measured by an ultrasonic oscillation method, namely the firmness between the carrier and the coating is measured by the falling rate after ultrasonic oscillation. Experiment the oven-dried and weighed sample was placed in a 100ml beaker, the beaker was placed in 300W ultrasonic waves for 20min, and the beaker was taken out, cleaned, oven-dried and weighed. The shedding rate was calculated using the following formula:
the peeling rate (mass before sample sonication-mass after sample sonication)/mass of coating × 100%, and the results of measurement of specific surface area and firmness of the coating are shown in table 1.
TABLE 1 test results
| Specific surface area (m)2/g) | Percent exfoliation (%) | |
| Example 1 | 81.8 | 2.01 |
| Example 2 | 103.7 | 3.23 |
| Example 3 | 236.1 | 3.62 |
| Example 4 | 98.3 | 2.81 |
| Example 5 | 215.7 | 3.78 |
| Comparative example 1 | 58.3 | 5.26 |
| Comparative example 2 | 24.9 | 1.43 |
| Comparative example 3 | 219.3 | 8.74 |
| Ceramic matrix | 0.83 | -- |
As can be seen from Table 1, the specific surface area of the coating is strongly related to the selected coating material, but is much higher than that of the ceramic substrate. From the coating peel rate data of each example and comparative example, the composite coating had better coating robustness. Although the firmness was higher with only the first coating, the specific surface area was lower than the other examples; whereas the comparative surface with only the second coating was higher but less robust. Overall, the composite coating has the characteristics of high coating firmness and high specific surface area.
The embodiments described above are some, but not all embodiments of the present application. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Claims (10)
1. A method for preparing a carrier with a composite coating, comprising:
drying and roasting the silicon carbide ceramic substrate with the surface coated with the coating liquid to obtain a ceramic carrier with a first coating on the surface; the coating liquid comprises ethyl orthosilicate and aluminum salt, and is acidic;
drying and roasting the ceramic carrier with the mixed solution coated on the surface, and forming a second coating on the surface of the first coating to obtain a ceramic carrier with a composite coating on the surface; the mixed solution comprises an aluminum source and a binder, wherein the aluminum source comprises at least one of aluminum oxide, aluminum hydroxide or pseudo-boehmite.
2. The method for preparing a carrier with a composite coating according to claim 1, wherein the mass ratio of the first coating to the silicon carbide ceramic matrix in the ceramic carrier with the first coating on the surface is 0.5-1g:100 g.
3. The method for producing the carrier with the composite coating according to claim 1 or 2, wherein the mass ratio of the second coating to the silicon carbide ceramic matrix in the ceramic carrier with the composite coating on the surface is 2 to 10g:100 g.
4. The preparation method of the carrier with the composite coating according to claim 1, wherein the coating solution further comprises water and ethanol, and the mass ratio of the ethyl orthosilicate to the water to the ethanol is 1 (0.1-0.5): (1-5).
5. The method for preparing a carrier with a composite coating according to claim 1, wherein the coating solution further comprises an acid, the acid comprises at least one of nitric acid, acetic acid, hydrochloric acid or oxalic acid, and the aluminum salt comprises at least one of aluminum nitrate and aluminum chloride.
6. The method for preparing a carrier with a composite coating according to claim 1, wherein the molar concentration of the aluminum salt in the coating liquid is 0.3-1.5 mol/L.
7. The method for preparing a carrier with a composite coating according to claim 5 or 6, wherein the aluminum salt is aluminum nitrate, and the mass ratio of the ethyl orthosilicate to the aluminum nitrate is 1: (3-10).
8. The method for preparing the carrier with the composite coating according to claim 1, wherein the binder is aluminum nitrate, the mixed solution further comprises water, and the mass ratio of the aluminum nitrate to the aluminum oxide to the water is 1 (1-3): (2-5).
9. The method for preparing the carrier with the composite coating according to claim 8, wherein the mixed solution further comprises polyethylene glycol, and the mass ratio of the aluminum nitrate to the alumina to the water to the polyethylene glycol is 1 (1-3): (2-5): (0.01-0.05).
10. The method for preparing a carrier with a composite coating according to claim 1, wherein the silicon carbide ceramic matrix has a three-dimensional interconnected mesh structure, and the pore size of the mesh is 0.5mm to 8 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010133698.XA CN111250124A (en) | 2020-02-28 | 2020-02-28 | Preparation method of carrier with composite coating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010133698.XA CN111250124A (en) | 2020-02-28 | 2020-02-28 | Preparation method of carrier with composite coating |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111250124A true CN111250124A (en) | 2020-06-09 |
Family
ID=70943028
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010133698.XA Pending CN111250124A (en) | 2020-02-28 | 2020-02-28 | Preparation method of carrier with composite coating |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111250124A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116375503A (en) * | 2023-03-03 | 2023-07-04 | 河南省锋泽新材料有限公司 | Composite ceramic supporting plate |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101653724A (en) * | 2009-09-10 | 2010-02-24 | 上海纳米技术及应用国家工程研究中心有限公司 | Ceramics catalyst surface active coating and its preparation method |
| CN102049312A (en) * | 2009-10-27 | 2011-05-11 | 中国石油化工股份有限公司 | Preparation method of catalytic combustion catalyst |
| CN104549253A (en) * | 2013-10-22 | 2015-04-29 | 中国石油化工股份有限公司 | Catalyst for catalytic combustion and preparation method thereof |
| CN104549529A (en) * | 2013-10-22 | 2015-04-29 | 中国石油化工股份有限公司 | High-firmness honeycomb ceramic carrier and preparation method thereof |
| CN105113213A (en) * | 2015-07-21 | 2015-12-02 | 上海工程技术大学 | Method for preparation of antioxidant composite coating on carbon fiber surface |
-
2020
- 2020-02-28 CN CN202010133698.XA patent/CN111250124A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101653724A (en) * | 2009-09-10 | 2010-02-24 | 上海纳米技术及应用国家工程研究中心有限公司 | Ceramics catalyst surface active coating and its preparation method |
| CN102049312A (en) * | 2009-10-27 | 2011-05-11 | 中国石油化工股份有限公司 | Preparation method of catalytic combustion catalyst |
| CN104549253A (en) * | 2013-10-22 | 2015-04-29 | 中国石油化工股份有限公司 | Catalyst for catalytic combustion and preparation method thereof |
| CN104549529A (en) * | 2013-10-22 | 2015-04-29 | 中国石油化工股份有限公司 | High-firmness honeycomb ceramic carrier and preparation method thereof |
| CN105113213A (en) * | 2015-07-21 | 2015-12-02 | 上海工程技术大学 | Method for preparation of antioxidant composite coating on carbon fiber surface |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116375503A (en) * | 2023-03-03 | 2023-07-04 | 河南省锋泽新材料有限公司 | Composite ceramic supporting plate |
| CN116375503B (en) * | 2023-03-03 | 2024-08-20 | 河南省锋泽新材料有限公司 | Composite ceramic supporting plate |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4239656A (en) | Catalyst for purifying exhaust gases and carrier for the catalyst | |
| JPH08325015A (en) | Sol-gel preparative method for producing sphere, microsphereand wash coat of pure and mixed zirconia oxide, useful as catalyst or catalyst carrier | |
| CN104661752B (en) | Composite material, electrode film and process for producing same, electrode terminal and process for producing same, base and process for producing same, and bonding material and process for producing base by bonding components with bonding material | |
| JPH04244232A (en) | Improved alumina-ceria catalyst coating film | |
| JPH0760118A (en) | Noble metal catalyst involving supporting material for oxygen ion conductivity | |
| CN1038412A (en) | Steam reforming catalysts | |
| JP2014510620A (en) | Metal structure catalyst and method for producing the same | |
| CN111250124A (en) | Preparation method of carrier with composite coating | |
| US4277376A (en) | Process for the manufacture of a monolithic support for catalysts suitable for use in controlling carbon monoxide emissions | |
| JPH0657320B2 (en) | Exhaust gas purification catalyst manufacturing method | |
| CN103212450B (en) | Method for preparing alumina catalyst carrier on stainless steel base body | |
| JP2003527277A (en) | Monolithic alpha-alumina articles with controlled porosity and sol-gel process for making those articles | |
| KR20180098200A (en) | Ni-based catalyst for SMR reaction coated on metal foam with improved catalyst adhesion and reaction property, and Manufacturing method and Use thereof | |
| CN111330570A (en) | Three-way catalyst for gasoline vehicle and preparation method thereof | |
| JPH0259045A (en) | Catalyst carrier | |
| CN109521064A (en) | Based on WO3The room temperature NO of hollow sphere2Sensor and preparation method thereof | |
| CN115400783B (en) | Cordierite carrier coated molecular sieve catalyst and preparation method thereof | |
| CN112156814B (en) | CO purification medium, preparation method and application | |
| JP2002066337A (en) | Catalyst provided with high heat-transfer capability and preparation process of the same catalyst | |
| KR20220111765A (en) | Catalyst for Treating Hazardous Gas Generated in Semiconductor Manufacturing Process Using Metal Foam and Preparation Methods Thereof | |
| JPS5939346A (en) | Preparation of ceramic honeycomb type catalyst carrier | |
| JP4411566B2 (en) | Cordierite ceramic honeycomb structure catalyst carrier and method for producing the same | |
| JPS6031828A (en) | Catalyst for purifying exhaust gas and its preparation | |
| JP2002361092A (en) | Catalyst slurry for denitrating exhaust gas, denitration catalyst and method of producing them | |
| JP2002248357A (en) | Method for manufacturing plate type catalyst and plate type catalyst |
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 |