CN115254129A - Honeycomb body for purifying automobile exhaust and preparation method thereof - Google Patents

Honeycomb body for purifying automobile exhaust and preparation method thereof Download PDF

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CN115254129A
CN115254129A CN202210729764.9A CN202210729764A CN115254129A CN 115254129 A CN115254129 A CN 115254129A CN 202210729764 A CN202210729764 A CN 202210729764A CN 115254129 A CN115254129 A CN 115254129A
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honeycomb
preserving heat
slurry
honeycomb body
heating
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CN115254129B (en
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华国金
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Jiangyin Huayin Ceramics Mechanical&electrical Technology Co ltd
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    • 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
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/83—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with rare earths or actinides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9445—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
    • B01D53/9454—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific device
    • 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
    • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • B01J35/56—Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
    • B01J37/0063—Granulating
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0234—Impregnation and coating simultaneously
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/65—Catalysts not containing noble metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/01—Engine exhaust gases
    • 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
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

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  • Chemical Kinetics & Catalysis (AREA)
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Abstract

The invention discloses a honeycomb body for purifying automobile exhaust and a preparation method thereof2O3/ZrO2And a binder; the base layer is composed of Y2O3/ZrO2And PVB; the connecting layer is formed by Gd2O3/CeO2And PVB; the functional layer is made of La0.8Sr0.2CoO3And Gd2O3/CeO2And (3) preparing powder. The honeycomb body prepared by the inventionThe catalyst has good tail gas catalytic conversion effect, has obvious effect on the conversion of nitrogen oxides, hydrocarbons and CO at normal temperature or even low temperature, and has the characteristics of low cost and easy industrial application.

Description

Honeycomb body for purifying automobile exhaust and preparation method thereof
Technical Field
The invention belongs to the technical field of ceramics, and particularly relates to a honeycomb body for purifying automobile exhaust and a preparation method thereof.
Background
With the annual increase in the quantity of motor vehicles kept worldwide, automobile exhaust pollution has become one of the major air pollution sources. The main components of the automobile exhaust comprise CO and NOx、SOxVolatile organic compounds and particulate matter, and the like. At present, the honeycomb ceramic material is widely applied to the treatment of automobile exhaust. The surface of the honeycomb ceramic material is generally coated with alumina with larger specific surface area orSilica coating to increase the specific surface area of the honeycomb ceramic material. The catalytic coating is prepared by pulping to form a uniform slurry solution, coating the uniform slurry solution on the surface of honeycomb ceramic and roasting. Therefore, it is necessary to develop a slurry formulation and coating method with good dispersibility, high bonding strength and good reactivity. Whether the catalytic coating is uniformly dispersed on the surface of the carrier directly influences the catalytic activity of the monolithic catalyst, and further directly influences the purification effect of the aftertreatment system.
CeO2Has good oxygen storage and release capacity, can be used as a cocatalyst to be added into a three-way catalyst of automobile exhaust to serve as an oxygen buffer, and can pass through Ce when oxygen is rich3+Conversion to Ce4+Absorb oxygen to ensure NOxReduced by CO and HC, ceO when oxygen is insufficient2Releasing oxygen to oxidize CO and HC, thereby achieving effective purification of CO, HC and NOxThe purpose of (1). But due to the high temperature of the exhaust gas discharged by automobiles (>1000 c), the ceria catalyst is easily aged and sintered to cause a decrease in oxygen storage capacity.
In the prior art, chinese patent CN112717927B discloses a preparation method and application of an automobile exhaust treatment catalyst, the catalyst sequentially comprises a substrate layer, a coating layer and a loading layer, wherein the substrate layer is honeycomb ceramic; the coating layer comprises La2O3/Al2O3And a cerium-zirconium composite metal oxide; the load layer is noble metal, the noble metal is one or more of Pt, rh and Pd, and the catalyst has good catalytic effect, low cost and easy industrial application. However, the thermal shock resistance and the mechanical strength of the catalyst carrier cordierite honeycomb ceramic are not considered, so that the service performance of the catalyst is possibly reduced. For example, the gas temperature at the outlet of an automobile engine is about 800 ℃, and the ceramic carrier can repeatedly bear thermal shock impact from room temperature to 800 ℃ for a long time due to frequent starting and flameout of the automobile engine in use; if the thermal shock resistance (delta T) is poor, the honeycomb ceramic carrier can be cracked quickly, so that the catalytic purifier fails; the higher the DeltaT of the ceramic, the lower the coefficient of thermal expansion, and therefore thermal expansion systems are commonly used in the artNumbers distinguish and characterize Δ T of the honeycomb ceramic. And the honeycomb catalyst in the prior art has the catalysis temperature of more than 250 ℃, so that the application range of the honeycomb catalyst is limited.
Therefore, a honeycomb catalyst with excellent catalytic effect, low shedding rate, low catalytic temperature, good thermal shock resistance and good mechanical strength is needed in the field.
Disclosure of Invention
In view of the shortcomings of the prior art, the present invention provides a honeycomb body for purifying automobile exhaust and a method for preparing the same, so as to solve the above-mentioned problems in the background art.
In order to achieve the purpose, the invention provides the following technical scheme:
the honeycomb body for purifying the automobile exhaust sequentially comprises a honeycomb body carrier, a base layer, a connecting layer and a functional layer from inside to outside, wherein the honeycomb body carrier is made of NiO and Y2O3/ZrO2And a binder; the base layer is composed of Y2O3/ZrO2And PVB; the connecting layer is formed by Gd2O3/CeO2And PVB; the functional layer is made of La0.8Sr0.2CoO3And Gd2O3/CeO2And (3) preparing powder.
Preferably, the honeycomb carrier comprises the following raw materials in parts by weight: niO 25-35 parts, Y2O3/ZrO215-25 parts of binder and 4-8 parts of adhesive; said Y is2O3/ZrO2Middle Y2O3And ZrO2The molar mass ratio of (A) to (B) is 8:92; the NiO powder has a particle size of 0.5-1.5 μm, and Y is2O3/ZrO2The particle size of the powder is 0.3-0.6 μm; the binder is one or more of alpha-terpineol, phenolic resin and furan resin.
Preferably, the base layer comprises Y in percentage by mass2O3/ZrO225-35 percent of PVB, 0.5-1.5 percent of PVB and the balance of solvent ethanol; said Y is2O3/ZrO2Middle Y2O3And ZrO2The molar mass ratio of (A) to (B) is 8:92; the thickness of the base layer is 20-40μm。
Preferably, gd is calculated in the connecting layer according to mass percentage2O3/CeO220-30 percent of PVB, 1-2 percent of PVB and the balance of solvent ethanol; the Gd2O3/CeO2Middle Gd2O3With CeO2The molar mass ratio of (A) to (B) is 8:2; the thickness of the connecting layer is 20-30 μm.
Preferably, the functional layer contains, by mass percent, la0.8Sr0.2CoO3And Gd2O3/CeO220-25% of powder and the balance of solvent ethanol; the La0.8Sr0.2CoO3And Gd2O3/CeO2La in powder0.8Sr0.2CoO3With Gd2O3/CeO2The molar mass ratio of (1): 1-3; the Gd2O3/CeO2Middle Gd2O3With CeO2The molar mass ratio of (A) to (B) is 3:7; the thickness of the functional layer is 20-40 μm.
The invention also provides a preparation method of the honeycomb body for purifying the automobile exhaust, which comprises the following steps:
(1) Preparation of honeycomb carrier: niO and Y2O3/ZrO2Ball milling, adding binder, stirring, kneading into paste, placing into extruder, adjusting pressure of extruder to 25kgf/cm2Extruding under the condition of air-exhaust, slowly raising pressure to 40kgf/cm2Slowly extruding the honeycomb wet blank, cutting after the honeycomb column is extruded to the required length, then shaping at 200 ℃, taking out the green blank after shaping is finished, and calcining to obtain a honeycomb carrier;
(2) Dipping and coating the honeycomb body base layer: preparing base layer slurry, coating and covering the part, which does not need to be coated, of the honeycomb carrier obtained in the step (1) by using white glue, drying, immersing the part into the base layer slurry after drying is finished, soaking for 2-4min, then pulling up, throwing off excessive slurry, then blowing through honeycomb channels to finish primary coating, then reversely immersing the honeycomb structure into the base layer slurry, pulling up after 2-4min, throwing off excessive slurry, then blowing through the honeycomb channels to finish secondary coating, and then placing the honeycomb structure at room temperature for air drying and calcining to obtain the honeycomb coated with the base layer;
(3) Dip-coating the honeycomb connecting layer: preparing connecting layer slurry, namely coating and covering the part, which is not required to be coated, of the honeycomb body coated with the base layer and obtained in the step (2) by using white glue, then drying, immersing the honeycomb body into the base layer slurry after drying is finished, soaking the honeycomb body for 2-4min, then pulling up the honeycomb body, throwing off excessive slurry, then blowing through honeycomb channels to finish primary coating, then reversely immersing the honeycomb structure body into the connecting layer slurry, pulling up the honeycomb body after 2-4min, throwing off excessive slurry, then blowing through the honeycomb channels to finish secondary coating, and then placing the honeycomb structure body at room temperature for air drying and calcining to obtain the honeycomb body coated with the connecting layer;
(4) Dipping and coating a honeycomb functional layer: and (3) preparing functional layer slurry, namely coating and covering the part, which is not required to be coated, of the honeycomb body coated with the connecting layer and obtained in the step (3) by using white glue, drying, soaking the honeycomb body into the base layer slurry after drying is finished, dipping the honeycomb body for 2-4min, then pulling up the honeycomb body, throwing off excessive slurry, blowing through the honeycomb channels, completing primary coating, reversely dipping the honeycomb structure body into the functional layer slurry, pulling up the honeycomb structure after 2-4min, throwing off excessive slurry, then blowing through the honeycomb channels, completing secondary coating, and then placing the honeycomb structure body at room temperature for air drying and calcining to obtain the honeycomb body for purifying the automobile exhaust.
Preferably, the shaping process in the step (1) comprises the following steps: heating to 60 ℃ at the rate of 1-2 ℃/min under the condition of room temperature, then preserving heat for 1-3h, heating to 120 ℃ at the rate of 1-2 ℃/min, then preserving heat for 1-3h, heating to 200 ℃ at the rate of 1-2 ℃/min, finally preserving heat for 3-5h, and naturally cooling to room temperature;
the calcining process comprises the following steps: heating to 300 ℃ at the rate of 4-6 ℃/min under the condition of room temperature, then preserving heat for 1-3h, heating to 600 ℃ at the rate of 4-6 ℃/min, then preserving heat for 1-3h, heating to 900 ℃ at the rate of 4-6 ℃/min, then preserving heat for 1-3h, heating to 1100 ℃ at the rate of 4-6 ℃/min, finally preserving heat for 3-5h, and naturally cooling to room temperature.
Preferably, the calcination process in step (2) is: heating to 500 ℃ at the speed of 2-4 ℃/min under the condition of room temperature, then preserving heat for 1-3h, heating to 1200 ℃ at the speed of 1-2 ℃/min, then preserving heat for 4-6h, heating to 1300-1400 ℃ at the speed of 1-2 ℃/min, then preserving heat for 6-8h, cooling to 1000 ℃ at the speed of 1-2 ℃/min, then preserving heat for 1-3h, cooling to 500 ℃ at the speed of 1-2 ℃/min, finally preserving heat for 1-3h, and naturally cooling to room temperature.
Preferably, the calcination process in step (3) is: heating to 500 ℃ at the speed of 2-4 ℃/min under the condition of room temperature, then preserving heat for 1-3h, heating to 1200-1250 ℃ at the speed of 1-2 ℃/min, then preserving heat for 4-6h, then cooling to 1000 ℃ at the speed of 1-2 ℃/min, then preserving heat for 1-3h, then cooling to 500 ℃ at the speed of 1-2 ℃/min, finally preserving heat for 3-5h, and then naturally cooling to room temperature.
Preferably, the calcination process in step (4) is: the calcining temperature is 900-1250 ℃, and the calcining time is 4-6h.
Compared with the prior art, the invention has the following beneficial effects:
(1) The honeycomb body for purifying the automobile exhaust prepared by the invention uses NiO and Y2O3/ZrO2And a bonding agent to prepare a honeycomb carrier, and NiO and Y are mixed by the bonding agent2O3/ZrO2The YSZ ceramic material has the advantages of high melting point, high hardness, good thermal shock resistance stability, low density, low thermal conductivity, linear expansion coefficient close to that of a metal material, high strength and toughness, chemical corrosion resistance and the like, and can improve the thermal shock resistance of the honeycomb body; simultaneously coating a layer of Y on the surface of the carrier2O3/ZrO2The base layer has high bonding strength with the carrier and similar thermal expansion coefficient, and the coating is not easy to fall off.
(2) Gd is introduced into the connecting layer of the honeycomb body for purifying automobile exhaust gas prepared by the invention2O3/CeO2Wherein cerium ions form a cerium-zirconium solid solution with the zirconium crystals in the substrate to improve temperature resistance, and the cerium-zirconium solid solution is used as a promoter to improve temperature resistanceCatalytic performance of high-volume honeycombs; and the connecting layer coating is uniformly dispersed and tightly tiled on the surface of the base layer, and particles in the connecting layer are tightly and fully contacted with the base layer after calcination, so that the combination is firm and the falling rate is low.
(3) The functional layer of the honeycomb body for purifying the automobile exhaust prepared by the invention is La0.8Sr0.2CoO3And Gd2O3/CeO2Powder of Gd therein2O3/CeO2The powder and the connecting layer have good compatibility, and the bonding strength of the functional layer and the connecting layer is improved, so that the functional layer and the connecting layer are not easy to fall off; meanwhile, the prepared honeycomb body has a good tail gas catalytic conversion effect, the existing honeycomb body catalyst is used at the temperature of more than 250 ℃, the honeycomb body can be used at normal temperature or even low temperature, the honeycomb body has a remarkable effect on the conversion of nitrogen oxides, hydrocarbons and CO, the application range of the honeycomb body is expanded, and the honeycomb body has the characteristics of low cost and easiness in industrial application.
(4) According to the preparation method of the honeycomb body for purifying the automobile exhaust, when different coatings are prepared, through different calcining processes, the coatings have good bonding strength, the surfaces of particles react with each other at a reasonable temperature rise and drop speed and within a reasonable heat preservation time, the sintering temperature is improved, the moving capacity of atoms is enhanced, the number of atoms overcoming energy barriers is increased, the surface energy of a system is reduced, the sample is densified, the particles are combined into a whole, the compressive strength of the honeycomb is improved, and meanwhile, the proper heat preservation time enables the internal and external crystal phases of the coatings to be uniform and can obtain proper crystal grain sizes, so that the catalytic performance of the honeycomb body is improved.
Detailed Description
The technical solutions of the present invention will be described below clearly and completely in conjunction with the embodiments, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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 invention.
Said Y is2O3/ZrO2The powder is purchased from Guangzhou Hongwu materials science and technology limited, and the particle size is 0.3-0.6 μm; the Gd2O3/CeO2The preparation method is prepared according to the literature (preparation and research of the LSM-LSC composite cathode of the solid oxide fuel cell, hou Zhifang, master thesis of university of great connectivity, 2005); la0.8Sr0.2CoO3According to the literature (mullite fiber ceramic loaded with La)0.8Sr0.2CoO3The preparation and the catalytic performance of the catalyst are obtained by the preparation of the catalyst, such as Zhongke, bilin, and the like, the university of south China university of Arbitrary (Nature science edition), 2006, 9 months); the phenolic resin is purchased from Henan Huanshan industry Co., ltd, and has a product number of 9100; the furan resin is purchased from Shandong Dennuo New Material science and technology Limited and has the brand number of DN1432; the PVB is produced by DuPont company of America, and the model is 9850; the cordierite powder is purchased from Lei-hang mineral product processing factory in Ling shou county, with the cargo number F-568.
Example 1
A preparation method of the honeycomb body for purifying the automobile exhaust comprises the following steps:
(1) Preparation of honeycomb carrier: 250g of NiO (particle size of 0.5 μm) and 150g Y were mixed2O3/ZrO2(Y2O3And ZrO2The molar mass ratio of (A) to (B) is 8:92, particle size of 0.3 μm), then adding 10g of alpha-terpineol and 30g of phenolic resin, stirring uniformly, kneading into paste, putting into an extruder, adjusting the pressure regulating valve of the extruder to 25kgf/cm2Extruding under the condition of air-exhaust, slowly raising pressure to 40kgf/cm2Slowly extruding a wet honeycomb blank, cutting after honeycomb columns are extruded to a required length, heating to 60 ℃ at the speed of 1 ℃/min at room temperature, then preserving heat for 1h, heating to 120 ℃ at the speed of 1 ℃/min, preserving heat for 1h, heating to 200 ℃ at the speed of 1 ℃/min, finally preserving heat for 3h, naturally cooling to room temperature for shaping, taking out the green blank for calcination after shaping is finished, wherein the calcination process comprises the following steps: heating to 300 deg.C at 4 deg.C/min at room temperature, maintaining for 1 hr, heating to 600 deg.C at 4 deg.C/min, maintaining for 1 hr, and heating at 4 deg.C/minHeating to 900 ℃, then preserving heat for 1h, then heating to 1100 ℃ at the speed of 4 ℃/min, finally preserving heat for 3h, and naturally cooling to room temperature to obtain the honeycomb carrier;
(2) Dipping and coating the honeycomb body base layer: preparing base layer slurry: mixing 250g Y2O3/ZrO2Powder (Y)2O3And ZrO2The molar mass ratio of (A) to (B) is 8:92, the particle size is 0.3 mu m), 5g of PVB is added into 745g of absolute ethyl alcohol, ultrasonic oscillation is carried out for 1h, then standing is carried out for 24h, ultrasonic oscillation is carried out for 15min again before coating, and the preparation of base layer slurry is finished; coating and covering the part, which does not need to be coated, of the honeycomb carrier obtained in the step (1) by using white glue, then drying, immersing the part into basic layer slurry after drying is finished, soaking for 2min, then pulling up, throwing off redundant slurry, then blowing through honeycomb channels to finish primary coating, then reversely immersing the honeycomb structure into the basic layer slurry, soaking for 2min, pulling up, throwing off redundant slurry, then blowing through the honeycomb channels, finishing secondary coating, then placing the honeycomb structure to be air-dried and calcined at room temperature, wherein the calcining process is as follows: heating to 500 ℃ at the speed of 2 ℃/min under the condition of room temperature, then preserving heat for 1h, heating to 1200 ℃ at the speed of 1 ℃/min, then preserving heat for 4h, heating to 1300 ℃ at the speed of 1 ℃/min, then preserving heat for 8h, then cooling to 1000 ℃ at the speed of 1 ℃/min, then preserving heat for 1h, cooling to 500 ℃ at the speed of 1 ℃/min, finally preserving heat for 1h, and naturally cooling to room temperature to obtain the honeycomb body coated with the base layer; the thickness of the base layer is 20 μm;
(3) Dip-coating the honeycomb connecting layer: preparing slurry of a connecting layer: 200g of Gd2O3/CeO2Powder (Gd)2O3With CeO2The molar mass ratio is 3: 7) 10g of PVB is added into 790 g of absolute ethyl alcohol, ultrasonic oscillation is carried out for 1 hour, then standing is carried out for 24 hours, and ultrasonic oscillation is carried out for 15 minutes again before coating, so that slurry preparation of the connecting layer is completed; coating and covering the part, which is not required to be coated, of the honeycomb body coated with the base layer and obtained in the step (2) by using white glue, then drying, immersing the dried honeycomb body into the slurry of the connecting layer for soaking for 2min, then pulling up, throwing off the redundant slurry, then blowing through the honeycomb pore channels to complete one-time coating, then reversely immersing the honeycomb structure body into the slurry of the connecting layer, soaking for 2min, pulling up, throwing off much honeycomb structureAnd (3) blowing through the honeycomb pore channels to finish secondary coating, and then placing the honeycomb structure body at room temperature for air drying and calcining, wherein the calcining process comprises the following steps: heating to 500 ℃ at the speed of 2 ℃/min under the condition of room temperature, then preserving heat for 1h, heating to 1200 ℃ at the speed of 1 ℃/min, then preserving heat for 6h, then cooling to 1000 ℃ at the speed of 1 ℃/min, then preserving heat for 1h, then cooling to 500 ℃ at the speed of 1 ℃/min, finally preserving heat for 3h, and naturally cooling to room temperature to obtain the honeycomb body coated with the connecting layer; the thickness of the connecting layer is 20 μm;
(4) Dipping and coating a honeycomb body functional layer: functional layer slurry preparation: 200g of La0.8Sr0.2CoO3And Gd2O3/CeO2Powder (wherein, la)0.8Sr0.2CoO3Has a mass of 85g, gd2O3/CeO2Has a mass of 115g and Gd2O3With CeO2The molar mass ratio is 3: 7) Adding the mixture into 800g of absolute ethyl alcohol, ultrasonically oscillating for 1h, standing for 24h, and ultrasonically oscillating again for 15min before coating to complete the preparation of the connecting layer slurry; coating and covering the part, which is not required to be coated, of the honeycomb body coated with the connecting layer and obtained in the step (3) by using white glue, drying, soaking the part, which is obtained after drying, in the slurry of the functional layer for 2min, then pulling up, throwing off excessive slurry, then blowing through the honeycomb pore channels to complete primary coating, then reversely soaking the honeycomb structure body in the slurry of the functional layer, soaking the part, which is obtained after 2min, pulling up, throwing off the excessive slurry, then blowing through the honeycomb pore channels to complete secondary coating, then placing the honeycomb structure body to be air-dried and calcined at room temperature, wherein the calcining process is as follows: the calcination temperature is 900 ℃, the calcination time is 6h, and the thickness of the functional layer is 20 μm, so as to obtain the honeycomb body for purifying the automobile exhaust.
Example 2
A preparation method of the honeycomb body for purifying the automobile exhaust comprises the following steps:
(1) Preparation of honeycomb carrier: 300g of NiO (particle size 1 μm) and 200g Y were mixed2O3/ZrO2(Y2O3And ZrO2The molar mass ratio of (A) to (B) is 8:92, particle size 0.5 μm) ball milled, followed by the addition of 15g of alpha-terpineol, 45g of phenolMixing aldehyde resin, kneading into paste, extruding, regulating pressure to 25kgf/cm2Extruding under the condition of air-exhaust, slowly raising pressure to 40kgf/cm2Slowly extruding a wet honeycomb blank, cutting after honeycomb columns are extruded to a required length, heating to 60 ℃ at the speed of 1 ℃/min at room temperature, then preserving heat for 2h, heating to 120 ℃ at the speed of 1 ℃/min, preserving heat for 2h, heating to 200 ℃ at the speed of 1 ℃/min, finally preserving heat for 4h, naturally cooling to room temperature for shaping, taking out the green blank for calcination after shaping is finished, wherein the calcination process comprises the following steps: heating to 300 ℃ at the speed of 5 ℃/min under the condition of room temperature, then preserving heat for 2h, heating to 600 ℃ at the speed of 5 ℃/min, then preserving heat for 2h, heating to 900 ℃ at the speed of 5 ℃/min, then preserving heat for 2h, heating to 1100 ℃ at the speed of 5 ℃/min, finally preserving heat for 4h, and naturally cooling to room temperature to obtain the honeycomb carrier;
(2) Dipping and coating the honeycomb substrate: preparing base layer slurry: mixing 300g Y2O3/ZrO2Powder (Y)2O3And ZrO2The molar mass ratio of (A) to (B) is 8:92, the particle size is 0.5 mu m), 10g PVB is added into 690g absolute ethyl alcohol, ultrasonic oscillation is carried out for 1h, then standing is carried out for 24h, ultrasonic oscillation is carried out again for 15min before coating, and the preparation of base layer slurry is completed; coating and covering the part, which does not need to be coated, of the honeycomb carrier obtained in the step (1) by using white glue, then drying, immersing the part into basic layer slurry after drying is finished, soaking for 3min, then pulling up, throwing off redundant slurry, then blowing through honeycomb channels to finish primary coating, then reversely immersing the honeycomb structure into the basic layer slurry, soaking for 3min, pulling up, throwing off redundant slurry, then blowing through the honeycomb channels to finish secondary coating, then placing the honeycomb structure to be air-dried and calcined at room temperature, wherein the calcining process is as follows: heating to 500 ℃ at the speed of 3 ℃/min under the condition of room temperature, then preserving heat for 2h, heating to 1200 ℃ at the speed of 1 ℃/min, then preserving heat for 5h, heating to 1400 ℃ at the speed of 1 ℃/min, then preserving heat for 7h, then cooling to 1000 ℃ at the speed of 1 ℃/min, then preserving heat for 2h, cooling to 500 ℃ at the speed of 1 ℃/min, finally preserving heat for 2h, and naturally cooling to room temperature to obtain the honeycomb body coated with the base layer; thickness of the base layerThe degree is 30 μm;
(3) Dip-coating the honeycomb connecting layer: preparing connecting layer slurry: mixing 250g of Gd2O3/CeO2Powder (Gd)2O3With CeO2The molar mass ratio is 3: 7) Adding 15g of PVB into 735g of absolute ethyl alcohol, ultrasonically oscillating for 1h, standing for 24h, and ultrasonically oscillating for 15min again before coating to complete the preparation of the slurry of the connecting layer; coating and covering the part, which is not required to be coated, of the honeycomb body coated with the base layer and obtained in the step (2) by using white glue, drying, immersing the part into the slurry of the connecting layer after drying, dipping the part for 3min, pulling up, throwing off excessive slurry, blowing through the honeycomb pore channels to finish primary coating, reversely immersing the honeycomb structure into the slurry of the connecting layer, dipping the part for 3min, pulling up, throwing off the excessive slurry, blowing through the honeycomb pore channels to finish secondary coating, placing the honeycomb structure to be air-dried and calcined at room temperature, wherein the calcining process is as follows: heating to 500 ℃ at the speed of 3 ℃/min under the condition of room temperature, then preserving heat for 2h, heating to 1250 ℃ at the speed of 1 ℃/min, then preserving heat for 5h, then cooling to 1000 ℃ at the speed of 1 ℃/min, then preserving heat for 2h, then cooling to 500 ℃ at the speed of 1 ℃/min, finally preserving heat for 4h, and naturally cooling to room temperature to obtain the honeycomb body coated with the connecting layer; the thickness of the connecting layer is 25 μm;
(4) Dipping and coating a honeycomb functional layer: functional layer slurry preparation: 230g of La0.8Sr0.2CoO3And Gd2O3/CeO2Powder (wherein, la)0.8Sr0.2CoO3The mass of the Gd strain is 62g2O3/CeO2The mass is 168g2O3With CeO2The molar mass ratio is 3: 7) Adding the mixture into 770g of absolute ethyl alcohol, ultrasonically oscillating for 1h, standing for 24h, and ultrasonically oscillating again for 15min before coating to finish the preparation of the connecting layer slurry; coating and covering the part, which is not required to be coated, of the honeycomb body coated with the connecting layer and obtained in the step (3) by using white glue, then drying, soaking the part, which is obtained in the step (3), in the slurry of the functional layer after drying for 3min, then pulling up, throwing off redundant slurry, then blowing through the honeycomb pore channel to complete primary coating, then reversely soaking the honeycomb structure body in the slurry of the functional layer, pulling up after soaking for 3min, throwing off redundant slurryAnd (2) slurry, then blowing through the honeycomb pore channels to finish secondary coating, and then placing the honeycomb structure body at room temperature for air drying and calcining, wherein the calcining process comprises the following steps: the calcination temperature is 1100 ℃, the calcination time is 5 hours, and the thickness of the functional layer is 30 μm, so that the honeycomb body for purifying the automobile exhaust is obtained.
Example 3
A preparation method of the honeycomb body for purifying the automobile exhaust comprises the following steps:
(1) Preparation of honeycomb carrier: 350g of NiO (particle size 1.5 μm) and 250g Y were mixed2O3/ZrO2(Y2O3And ZrO2The molar mass ratio of (a) to (b) is 8:92, particle size of 0.6 μm), then 30g of alpha-terpineol and 50g of furan resin are added, stirred uniformly and kneaded into paste, the paste is placed into an extruder, and the pressure regulating valve of the extruder is adjusted to 25kgf/cm2Extruding under air-extracting condition, slowly increasing pressure to 40kgf/cm2Slowly extruding a wet honeycomb blank, cutting after honeycomb columns are extruded to a required length, heating to 60 ℃ at the speed of 2 ℃/min at room temperature, then preserving heat for 3h, heating to 120 ℃ at the speed of 2 ℃/min, preserving heat for 3h, heating to 200 ℃ at the speed of 2 ℃/min, finally preserving heat for 5h, naturally cooling to room temperature for shaping, taking out a green blank for calcining after shaping is finished, wherein the calcining process comprises the following steps: heating to 300 ℃ at the speed of 6 ℃/min under the condition of room temperature, then preserving heat for 3h, heating to 600 ℃ at the speed of 6 ℃/min, then preserving heat for 3h, heating to 900 ℃ at the speed of 6 ℃/min, then preserving heat for 3h, heating to 1100 ℃ at the speed of 6 ℃/min, finally preserving heat for 5h, and naturally cooling to room temperature to obtain the honeycomb carrier;
(2) Dipping and coating the honeycomb substrate: preparing base layer slurry: 350g Y2O3/ZrO2Powder (Y)2O3And ZrO2The molar mass ratio of (a) to (b) is 8:92, the particle size is 0.6 mu m), 15g of PVB is added into 635g of absolute ethyl alcohol, ultrasonic oscillation is carried out for 1h, then standing is carried out for 24h, ultrasonic oscillation is carried out for 15min again before coating, and base layer slurry preparation is completed; coating and covering the part of the honeycomb carrier obtained in the step (1) which is not required to be coated with white glue, and then drying to finish dryingThe back is soaked in basic unit's thick liquids and is pulled up after 4min of flooding, gets rid of unnecessary thick liquids, blows through the honeycomb pore and accomplishes once coating subsequently, and then with honeycomb structure reverse impregnation basic unit's thick liquids, the flooding 4min back is pulled up, gets rid of unnecessary thick liquids, blows through the honeycomb pore after that, accomplishes the secondary coating, then places the honeycomb structure and air-dries, calcines at room temperature, and the calcination technology is: heating to 500 ℃ at the speed of 4 ℃/min under the condition of room temperature, then preserving heat for 3h, heating to 1200 ℃ at the speed of 2 ℃/min, then preserving heat for 6h, heating to 1400 ℃ at the speed of 2 ℃/min, then preserving heat for 6h, then cooling to 1000 ℃ at the speed of 2 ℃/min, then preserving heat for 3h, cooling to 500 ℃ at the speed of 2 ℃/min, finally preserving heat for 3h, and naturally cooling to room temperature to obtain the honeycomb body coated with the base layer; the thickness of the base layer is 40 μm;
(3) Dip-coating the honeycomb connecting layer: preparing slurry of a connecting layer: 300g of Gd2O3/CeO2Powder (Gd)2O3With CeO2The molar mass ratio is 3: 7) Adding 20g of PVB into 680g of absolute ethyl alcohol, performing ultrasonic oscillation for 1 hour, standing for 24 hours, and performing ultrasonic oscillation again for 15min before coating to complete the preparation of the slurry of the connecting layer; coating and covering the part, which is not required to be coated, of the honeycomb body coated with the base layer and obtained in the step (2) by using white glue, then drying, soaking the part, which is obtained after drying, in the slurry of the connecting layer, dipping the part for 4min, then pulling up, throwing off the redundant slurry, then blowing through the honeycomb pore channel to complete primary coating, then reversely soaking the honeycomb body in the slurry of the connecting layer, dipping the part, which is obtained after drying, pulling up, throwing off the redundant slurry, then blowing through the honeycomb pore channel to complete secondary coating, then placing the honeycomb body to be air-dried at room temperature, and calcining, wherein the calcining process is as follows: heating to 500 ℃ at the speed of 4 ℃/min under the condition of room temperature, then preserving heat for 3h, heating to 1250 ℃ at the speed of 2 ℃/min, then preserving heat for 4h, then cooling to 1000 ℃ at the speed of 2 ℃/min, then preserving heat for 3h, then cooling to 500 ℃ at the speed of 2 ℃/min, finally preserving heat for 5h, and naturally cooling to room temperature to obtain the honeycomb body coated with the connecting layer; the thickness of the connecting layer is 30 μm;
(4) Dipping and coating a honeycomb functional layer: functional layer slurry preparation: 250g of La0.8Sr0.2CoO3And Gd2O3/CeO2Powder (wherein, la)0.8Sr0.2CoO3Has a mass of 50g, gd2O3/CeO2With a mass of 200g2O3With CeO2The molar mass ratio is 3: 7) Adding the mixture into 750g of absolute ethyl alcohol, ultrasonically oscillating for 1h, standing for 24h, and ultrasonically oscillating again for 15min before coating to complete the preparation of the connecting layer slurry; coating and covering the part, which is not required to be coated, of the honeycomb body coated with the connecting layer and obtained in the step (3) by using white glue, then drying, soaking the part, which is obtained in the step (3), in the slurry of the functional layer after drying is finished, pulling up the part after soaking for 4min, throwing off redundant slurry, then blowing through the honeycomb pore channel to finish primary coating, then reversely soaking the honeycomb structure body in the slurry of the functional layer, pulling up the part after soaking for 4min, throwing off redundant slurry, then blowing through the honeycomb pore channel to finish secondary coating, then placing the honeycomb structure body to be air-dried and calcined at room temperature, wherein the calcining process is as follows: the calcination temperature is 1250 ℃, the calcination time is 4h, and the thickness of the functional layer is 40 μm, so that the honeycomb body for purifying the automobile exhaust is obtained.
Comparative example 1
A preparation method of the honeycomb body for purifying the automobile exhaust comprises the following steps:
(1) Preparation of honeycomb carrier: adding 400g of cordierite powder into 40g of phenolic resin, stirring uniformly, kneading into paste, putting into an extruder, adjusting the pressure of the extruder to 25kgf/cm2Extruding under air-extracting condition, slowly increasing pressure to 40kgf/cm2Slowly extruding the honeycomb wet blank, cutting after the honeycomb column is extruded to the required length, then shaping at 200 ℃, taking out the green blank for calcination at 1400 ℃ for 4 hours after shaping is finished, and obtaining a honeycomb carrier;
(2) Dipping and coating the honeycomb body base layer: preparing base layer slurry: mixing 250g Y2O3/ZrO2Powder (Y)2O3And ZrO2The molar mass ratio of (A) to (B) is 8:92, the particle size is 0.3 mu m), 5g of PVB is added into 745g of absolute ethyl alcohol, ultrasonic oscillation is carried out for 1h, then standing is carried out for 24h, ultrasonic oscillation is carried out for 15min again before coating, and the preparation of base layer slurry is finished; the honeycomb body obtained in the step (1) is treatedThe part that does not need the coating on the carrier is coated with the white glue and is covered, and is then dry, dip in basic unit's thick liquids after the drying is accomplished and pull up after 2min of flooding in the thick liquids of flooding, get rid of unnecessary thick liquids, blow through the honeycomb pore and accomplish primary coating, with honeycomb structure reverse dip basic unit's thick liquids afterwards, dip and pull up after 2min, get rid of unnecessary thick liquids, blow through the honeycomb pore after that, accomplish the secondary coating, then place the honeycomb structure air-dry at room temperature, calcine, the calcination technology is: heating to 500 ℃ at the speed of 2 ℃/min under the condition of room temperature, then preserving heat for 1h, heating to 1200 ℃ at the speed of 1 ℃/min, then preserving heat for 4h, heating to 1300 ℃ at the speed of 1 ℃/min, then preserving heat for 8h, then cooling to 1000 ℃ at the speed of 1 ℃/min, then preserving heat for 1h, then cooling to 500 ℃ at the speed of 1 ℃/min, finally preserving heat for 1h, and naturally cooling to room temperature to obtain the honeycomb body coated with the base layer; the thickness of the base layer is 20 μm;
(3) Dip-coating the honeycomb connecting layer: preparing connecting layer slurry: 200g of Gd2O3/CeO2Powder (Gd)2O3With CeO2The molar mass ratio is 3: 7) 10g of PVB is added into 790 g of absolute ethyl alcohol, ultrasonic oscillation is carried out for 1 hour, then standing is carried out for 24 hours, and ultrasonic oscillation is carried out for 15 minutes again before coating, so that slurry preparation of the connecting layer is completed; coating and covering the part, which is not required to be coated, of the honeycomb body coated with the base layer and obtained in the step (2) by using white glue, drying, immersing the part into the slurry of the connecting layer after drying, dipping for 2min, pulling up, throwing off excessive slurry, blowing through the honeycomb pore channels to finish primary coating, reversely immersing the honeycomb structure into the slurry of the connecting layer, dipping for 2min, pulling up, throwing off the excessive slurry, blowing through the honeycomb pore channels to finish secondary coating, placing the honeycomb structure to be air-dried and calcined at room temperature, wherein the calcining process is as follows: heating to 500 ℃ at the speed of 2 ℃/min under the condition of room temperature, then preserving heat for 1h, heating to 1200 ℃ at the speed of 1 ℃/min, then preserving heat for 6h, then cooling to 1000 ℃ at the speed of 1 ℃/min, then preserving heat for 1h, then cooling to 500 ℃ at the speed of 1 ℃/min, finally preserving heat for 3h, and naturally cooling to room temperature to obtain the honeycomb body coated with the connecting layer; the thickness of the connecting layer is 20 μm;
(4) Dipping and coating a honeycomb body functional layer: function(s)Preparing layer slurry: 200g of La0.8Sr0.2CoO3And Gd2O3/CeO2Powder (wherein, la)0.8Sr0.2CoO3Has a mass of 85g, gd2O3/CeO2Has a mass of 115g and Gd2O3With CeO2The molar mass ratio is 3: 7) Adding the mixture into 800g of absolute ethyl alcohol, performing ultrasonic oscillation for 1 hour, then standing for 24 hours, and performing ultrasonic oscillation again for 15min before coating to complete the preparation of the slurry of the connecting layer; coating and covering the part, which is not required to be coated, of the honeycomb body coated with the connecting layer and obtained in the step (3) by using white glue, drying, soaking the part, which is obtained after drying, in the slurry of the functional layer for 2min, then pulling up, throwing off excessive slurry, then blowing through the honeycomb pore channels to complete primary coating, then reversely soaking the honeycomb structure body in the slurry of the functional layer, soaking the part, which is obtained after 2min, pulling up, throwing off the excessive slurry, then blowing through the honeycomb pore channels to complete secondary coating, then placing the honeycomb structure body to be air-dried and calcined at room temperature, wherein the calcining process is as follows: the calcination temperature is 900 ℃, the calcination time is 6h, and the thickness of the functional layer is 20 μm, so as to obtain the honeycomb body for purifying the automobile exhaust.
Comparative example 2
A preparation method of the honeycomb body for purifying the automobile exhaust comprises the following steps:
(1) Preparation of honeycomb carrier: 250g of NiO (particle size of 0.5 μm) and 150g Y were mixed2O3/ZrO2(Y2O3And ZrO2The molar mass ratio of (A) to (B) is 8:92, particle size of 0.3 μm), then adding 10g of alpha-terpineol and 30g of phenolic resin, stirring uniformly, kneading into paste, putting into an extruder, adjusting the pressure regulating valve of the extruder to 25kgf/cm2Extruding under air-extracting condition, slowly increasing pressure to 40kgf/cm2Slowly extruding the wet honeycomb blank, cutting after the honeycomb column is extruded to the required length, heating to 60 ℃ at the speed of 1 ℃/min at room temperature, then preserving heat for 1h, heating to 120 ℃ at the speed of 1 ℃/min, preserving heat for 1h, heating to 200 ℃ at the speed of 1 ℃/min, finally preserving heat for 3h, naturally cooling to room temperature for shaping, taking out the green blank for calcining after shaping, and the calcining processComprises the following steps: heating to 300 ℃ at the speed of 4 ℃/min under the condition of room temperature, then preserving heat for 1h, heating to 600 ℃ at the speed of 4 ℃/min, then preserving heat for 1h, heating to 900 ℃ at the speed of 4 ℃/min, then preserving heat for 1h, heating to 1100 ℃ at the speed of 4 ℃/min, finally preserving heat for 3h, and naturally cooling to room temperature to obtain the honeycomb carrier;
(2) Dipping and coating a honeycomb body functional layer: functional layer slurry preparation: 200g of La0.8Sr0.2CoO3And Gd2O3/CeO2Powder (wherein, la)0.8Sr0.2CoO3Has a mass of 85g, gd2O3/CeO2Has a mass of 115g and Gd2O3With CeO2The molar mass ratio is 3: 7) Adding the mixture into 800g of absolute ethyl alcohol, ultrasonically oscillating for 1h, standing for 24h, and ultrasonically oscillating again for 15min before coating to complete the preparation of the connecting layer slurry; coating and covering the part, which does not need to be coated, of the honeycomb carrier obtained in the step (1) by using white glue, then drying, immersing the honeycomb carrier into functional layer slurry after drying is finished, soaking for 2min, then pulling up, throwing off redundant slurry, then blowing through honeycomb channels to finish primary coating, then reversely immersing the honeycomb structure into the functional layer slurry, soaking for 2min, pulling up, throwing off redundant slurry, then blowing through the honeycomb channels to finish secondary coating, then placing the honeycomb structure to be air-dried and calcined at room temperature, wherein the calcining process is as follows: the calcination temperature is 900 ℃, the calcination time is 6h, and the thickness of the functional layer is 20 μm, so as to obtain the honeycomb body for purifying the automobile exhaust.
The honeycomb bodies obtained in examples 1 to 3 and comparative examples 1 to 2 were subjected to the following performance tests:
and (3) testing the falling rate: at a distance of 1.5cm from the section of the honeycomb body, the section of each unit of the catalyst was uniformly purged with compressed air at 10bar for 120s, and the catalyst dropping rate was calculated according to the calculation formula. The peeling rate = (honeycomb catalyst weight before purging-honeycomb catalyst weight after purging)/washcoat loading weight before purging × 100%.
And (3) testing the thermal expansion coefficient: the test was carried out according to standard QB/T1321-2012 "determination method of mean linear thermal expansion coefficient of ceramic materials". The test results are given in table 1 below:
TABLE 1 Honeycomb coating spalling Rate and thermal expansion coefficient Performance
Rate of fall/%) Coefficient of thermal expansion/x 10-6℃(25-800℃)
Example 1 1.82 0.81
Example 2 1.37 0.72
Example 3 1.69 0.75
Comparative example 1 8.41 1.57
Comparative example 2 5.27 1.39
As can be seen from Table 1, the coating peeling rates of examples 1 to 3 were low, and the overall coating peeling was caused by the interaction between the coatingsThe falling rate is reduced; meanwhile, the honeycomb body has low thermal expansion coefficient which is less than 1x10-6The temperature is high, and the thermal shock resistance is good. The cordierite carrier used in comparative example 1 has low bonding strength with the coating, resulting in a significantly increased exfoliation rate and a large thermal expansion coefficient; in comparative example 2, the base layer and the tie layer were not added, but only one functional layer, which had a limited bonding strength with the carrier, was added, so that the peeling rate was increased.
The honeycomb prepared in example 1 was evaluated for its catalytic effect by the following specific method:
specification of honeycomb body: the diameter is 15mm, and the length is 40mm;
space velocity: 30000h-1；
Total flow rate: 600mL/min;
simulated gas composition: o is27000ppm, NO 1000ppm, CO 5000ppm and Ar as balance gas, in a simulated atmosphere, raising the temperature from room temperature to 50 ℃ by a program of 2 ℃/min, recording the steady-state pollutant conversion result, then continuously raising the temperature to 150 ℃ in sequence, and respectively recording the gas conversion of each temperature point. The results are given in table 2 below:
table 2 example 1 and comparative example 2 honeycomb catalytic performance
Figure BDA0003712670310000201
As can be seen from the above table 2, the honeycomb prepared by the invention has good catalytic conversion effect of tail gas, has good catalytic effect at 50 ℃ and 150 ℃, greatly reduces the catalytic temperature compared with the existing honeycomb catalyst, and has good application prospect.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. A honeycomb body for purifying automobile exhaust gas from insideThe composite material comprises a honeycomb carrier, a base layer, a connecting layer and a functional layer in sequence from outside, and is characterized in that the honeycomb carrier is made of NiO and Y2O3/ZrO2Preparing a composite material; the base layer is composed of Y2O3/ZrO2And PVB; the connecting layer is formed by Gd2O3/CeO2And PVB; the functional layer is made of La0.8Sr0.2CoO3And Gd2O3/CeO2And (3) preparing powder.
2. The honeycomb body for purifying automobile exhaust according to claim 1, wherein the honeycomb body carrier comprises the following raw materials in parts by weight: niO 25-35 parts, Y2O3/ZrO215-25 parts of binder and 4-8 parts of adhesive; said Y is2O3/ZrO2Middle Y2O3And ZrO2The molar mass ratio of (A) to (B) is 8:92; the NiO powder has a particle size of 0.5-1.5 μm, and Y is2O3/ZrO2The particle size of the powder is 0.3-0.6 μm; the binder is one or more of alpha-terpineol, phenolic resin and furan resin.
3. The honeycomb body for automobile exhaust gas purification according to claim 1, wherein Y is a mass percentage of the base layer2O3/ZrO225-35 percent of PVB, 0.5-1.5 percent of PVB and the balance of solvent ethanol; said Y is2O3/ZrO2Middle Y2O3And ZrO2The molar mass ratio of (A) to (B) is 8:92; the thickness of the base layer is 20-40 μm.
4. The honeycomb body for automobile exhaust gas purification according to claim 1, wherein Gd is present in the connecting layer in a mass percentage2O3/CeO220-30 percent of PVB, 1-2 percent of PVB and the balance of solvent ethanol; the Gd2O3/CeO2Middle Gd2O3With CeO2The molar mass ratio of (A) to (B) is 8:2; the thickness of the connecting layer is 20-30 μm.
5. The honeycomb body for automotive exhaust gas purification according to claim 1, wherein La is included in the functional layer by mass percentage0.8Sr0.2CoO3And Gd2O3/CeO220-25% of powder and the balance of solvent ethanol; the La0.8Sr0.2CoO3And Gd2O3/CeO2La in powder0.8Sr0.2CoO3With Gd2O3/CeO2The molar mass ratio of (1): 1-3; the Gd2O3/CeO2Middle Gd2O3With CeO2The molar mass ratio of (A) to (B) is 3:7; the thickness of the functional layer is 20-40 μm.
6. A method for preparing a honeycomb body for automobile exhaust gas purification according to any one of claims 1 to 5, comprising the steps of:
(1) Preparation of honeycomb carrier: niO and Y2O3/ZrO2Ball milling, adding binder, stirring, kneading into paste, placing into extruder, adjusting pressure of extruder to 25kgf/cm2Extruding under air-extracting condition, slowly increasing pressure to 40kgf/cm2Slowly extruding the honeycomb wet blank, cutting after the honeycomb column is extruded to the required length, then shaping at 200 ℃, taking out the green blank after shaping is finished, and calcining to obtain a honeycomb carrier;
(2) Dipping and coating the honeycomb body base layer: preparing base layer slurry, coating and covering the part, which does not need to be coated, of the honeycomb carrier obtained in the step (1) by using white glue, drying, immersing the part into the base layer slurry after drying is finished, soaking for 2-4min, then pulling up, throwing off excessive slurry, then blowing through honeycomb channels to finish primary coating, then reversely immersing the honeycomb structure into the base layer slurry, pulling up after 2-4min, throwing off excessive slurry, then blowing through the honeycomb channels to finish secondary coating, and then placing the honeycomb structure at room temperature for air drying and calcining to obtain the honeycomb coated with the base layer;
(3) Dip-coating the honeycomb connecting layer: preparing connecting layer slurry, namely coating and covering the part, which is not required to be coated, of the honeycomb body coated with the base layer and obtained in the step (2) by using white glue, then drying, immersing the honeycomb body into the base layer slurry after drying is finished, soaking the honeycomb body for 2-4min, then pulling up the honeycomb body, throwing off excessive slurry, then blowing through honeycomb channels to finish primary coating, then reversely immersing the honeycomb structure body into the connecting layer slurry, pulling up the honeycomb body after 2-4min, throwing off excessive slurry, then blowing through the honeycomb channels to finish secondary coating, and then placing the honeycomb structure body at room temperature for air drying and calcining to obtain the honeycomb body coated with the connecting layer;
(4) Dipping and coating a honeycomb body functional layer: and (4) preparing functional layer slurry, coating and covering the part, which is not required to be coated, of the honeycomb body coated with the connecting layer and obtained in the step (3) by using white glue, drying, immersing the part into the base layer slurry after drying is finished, dipping the part for 2-4min, pulling up, throwing off redundant slurry, blowing through the honeycomb pore channels to finish primary coating, immersing the honeycomb structure body into the functional layer slurry reversely, pulling up after 2-4min, throwing off redundant slurry, blowing through the honeycomb pore channels to finish secondary coating, and then placing the honeycomb structure body at room temperature for air drying and calcining to obtain the honeycomb body for purifying automobile exhaust.
7. The method for preparing the honeycomb body for automobile exhaust gas purification according to claim 6, wherein the shaping process in the step (1) is: heating to 60 ℃ at the rate of 1-2 ℃/min under the condition of room temperature, then preserving heat for 1-3h, heating to 120 ℃ at the rate of 1-2 ℃/min, then preserving heat for 1-3h, heating to 200 ℃ at the rate of 1-2 ℃/min, finally preserving heat for 3-5h, and naturally cooling to room temperature;
the calcination process comprises the following steps: heating to 300 ℃ at the rate of 4-6 ℃/min under the condition of room temperature, then preserving heat for 1-3h, heating to 600 ℃ at the rate of 4-6 ℃/min, then preserving heat for 1-3h, heating to 900 ℃ at the rate of 4-6 ℃/min, then preserving heat for 1-3h, heating to 1100 ℃ at the rate of 4-6 ℃/min, finally preserving heat for 3-5h, and naturally cooling to room temperature.
8. The method for preparing a honeycomb body for automotive exhaust gas purification according to claim 6, wherein the calcination process in step (2) is: heating to 500 ℃ at the speed of 2-4 ℃/min under the condition of room temperature, then preserving heat for 1-3h, heating to 1200 ℃ at the speed of 1-2 ℃/min, then preserving heat for 4-6h, heating to 1300-1400 ℃ at the speed of 1-2 ℃/min, then preserving heat for 6-8h, cooling to 1000 ℃ at the speed of 1-2 ℃/min, then preserving heat for 1-3h, cooling to 500 ℃ at the speed of 1-2 ℃/min, finally preserving heat for 1-3h, and naturally cooling to room temperature.
9. The method for preparing a honeycomb body for automobile exhaust gas purification according to claim 6, wherein the calcination process in the step (3) is: heating to 500 ℃ at the speed of 2-4 ℃/min under the condition of room temperature, then preserving heat for 1-3h, heating to 1200-1250 ℃ at the speed of 1-2 ℃/min, then preserving heat for 4-6h, then cooling to 1000 ℃ at the speed of 1-2 ℃/min, then preserving heat for 1-3h, then cooling to 500 ℃ at the speed of 1-2 ℃/min, finally preserving heat for 3-5h, and then naturally cooling to room temperature.
10. The method for preparing a honeycomb body for automobile exhaust gas purification according to claim 6, wherein the calcination process in the step (4) is: the calcining temperature is 900-1250 ℃, and the calcining time is 4-6h.
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CN101745375A (en) * 2008-12-15 2010-06-23 比亚迪股份有限公司 Cerium zirconium aluminum based multiple oxide material and preparing method thereof
WO2019088302A1 (en) * 2017-11-06 2019-05-09 新日本電工株式会社 Oxygen absorbing and releasing material, catalyst, exhaust gas purifying system, and exhaust gas treatment method
CN109772165A (en) * 2018-12-14 2019-05-21 深圳大学 A kind of tail gas clean-up reactor and preparation method thereof reacts pile with tail gas clean-up
CN111962098A (en) * 2020-08-17 2020-11-20 广东电网有限责任公司广州供电局 Oxygen electrode slurry of solid oxide electrolytic cell, preparation method of oxygen electrode slurry and solid oxide electrolytic cell
US20200406234A1 (en) * 2018-02-26 2020-12-31 Basf Corporation Catalyst for gasoline engine exhaust gas aftertreatment

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101745375A (en) * 2008-12-15 2010-06-23 比亚迪股份有限公司 Cerium zirconium aluminum based multiple oxide material and preparing method thereof
WO2019088302A1 (en) * 2017-11-06 2019-05-09 新日本電工株式会社 Oxygen absorbing and releasing material, catalyst, exhaust gas purifying system, and exhaust gas treatment method
US20200406234A1 (en) * 2018-02-26 2020-12-31 Basf Corporation Catalyst for gasoline engine exhaust gas aftertreatment
CN109772165A (en) * 2018-12-14 2019-05-21 深圳大学 A kind of tail gas clean-up reactor and preparation method thereof reacts pile with tail gas clean-up
CN111962098A (en) * 2020-08-17 2020-11-20 广东电网有限责任公司广州供电局 Oxygen electrode slurry of solid oxide electrolytic cell, preparation method of oxygen electrode slurry and solid oxide electrolytic cell

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