CN114100594B - Cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material and preparation method thereof - Google Patents

Cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material and preparation method thereof Download PDF

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CN114100594B
CN114100594B CN202111425631.4A CN202111425631A CN114100594B CN 114100594 B CN114100594 B CN 114100594B CN 202111425631 A CN202111425631 A CN 202111425631A CN 114100594 B CN114100594 B CN 114100594B
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cerium
zirconium
aluminum
catalytic material
oxide
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CN114100594A (en
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胡安明
孟祥光
齐悦
任昕
王斐
沈小艳
吕婧
陈黄琳
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Sichuan University
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    • 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
    • B01J23/10—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of rare earths
    • 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
    • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/02—Boron or aluminium; Oxides or hydroxides thereof
    • B01J21/04—Alumina
    • 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
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56—Platinum group metals
    • B01J23/63—Platinum group metals with rare earths or actinides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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    • 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
    • B01J23/84—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 arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/85—Chromium, molybdenum or tungsten
    • B01J23/86—Chromium
    • B01J23/862—Iron and chromium
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    • 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
    • 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
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Abstract

The invention provides a cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material, which consists of cerium-zirconium oxide nano particles and aluminum oxide micro particles, wherein the cerium-zirconium oxide nano particles are dispersedly loaded on the surface of the outer layer of the aluminum oxide micro particles to form a core-shell structure type composite catalytic material; the preparation method comprises the following steps: (1) preparing a micron-particle alumina material; (2) synthesizing cerium zirconium oxide nano material sol; (3) Mixing the alumina micron particle material prepared in the step (1) with the cerium zirconium oxide nano material sol synthesized in the step (2) to generate slurry, and drying and roasting to obtain a granular cerium zirconium-aluminum based oxide micro-nano composite catalytic material; (4) Coating the cerium zirconium-aluminum-based oxide micro-nano composite catalytic material obtained in the step (3) on a substrate after pulping, and drying and roasting to obtain a coated cerium zirconium-aluminum-based oxide micro-nano composite catalytic material; the supported noble metal is used for preparing the tail gas purifying catalyst of the fuel oil vehicle and other industrial catalysts.

Description

Cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material and preparation method thereof
Technical Field
The invention relates to a cerium-zirconium-aluminum-based oxide catalytic material and a preparation method thereof, in particular to a cerium-zirconium-aluminum-based oxide catalytic material prepared from a tail gas purification catalyst of a fuel vehicle and the like and other industrial catalysts and a preparation method thereof.
Background
The cerium-zirconium-aluminum-based oxide catalytic material is a catalytic material commonly used in a high-temperature resistant catalyst, for example, for manufacturing a three-way catalyst or a three-way catalyst (TWC) for purifying the tail gas of a gasoline vehicle, wherein alumina (Al) 2 O 3 ) As a support material for the noble metal active component; cerium zirconium oxide (CeO) 2 -ZrO 2 Co-solvent) as both carrier and oxygen storage/release material, tail gasOxygen is absorbed during medium oxygen enrichment and is released during oxygen deficiency to maintain dynamic oxygen balance so as to expand an air/fuel ratio window, so that the reactions of removing CO and HC by oxidation and removing NOx by reduction can simultaneously occur, and the oxygen is considered as a key material of a three-way catalyst. The cerium-zirconium-aluminum-based oxide catalytic material is also used for diesel vehicle tail gas purification oxidation catalysts (DOC), fuel vehicle particulate filter catalysts (DPF, GPF) and the like. In addition, the noble metal supported catalyst such as petroleum cracking catalyst, hydrogenation catalyst, etc. can also be used as the cerium-zirconium-aluminum-based oxide catalytic material. The alumina used as catalytic material has high heat stability, and the specific surface area is 50-150 m according to different roasting temperatures and time 2 (ii) a particle size of 1 to 25 μm; the cerium-zirconium oxide has low thermal stability and the specific surface area of 20-70 m 2 The particle size per gram is 1 to 25 μm. The type of the catalytic material composed of alumina and cerium zirconium oxide mainly includes three types, namely mixed type, miscible type and mixed-leaching type.
The mixed cerium-zirconium-aluminum-based oxide catalytic material is prepared by mixing aluminum oxide and cerium-zirconium oxide microparticles, and preparing a catalyst by carrying precious metals (Pt, pd and Rh) or respectively carrying precious metals and then mixing or coating the mixture layer by layer, and is widely used for manufacturing three-way catalysts. For example, patent CN1032749 (1989.05.10) discloses a rhodium-free three-way catalyst; CN1413769 (2003.04.30) discloses "three-way catalyst for automobile exhaust and preparation method thereof"; CN1824384 (2006.08.30) discloses a "high-performance low-precious metal three-way catalyst"; CN101161337 (2008.04.16) discloses "a three-way catalyst and its preparation method"; CN101433846 (2009.05.20) discloses a cerium-based composite oxide supported noble metal three-way catalyst and a preparation method thereof; CN102430403A (2012.05.02) discloses "a low precious metal content high efficiency three-way catalyst and its preparation method"; CN103143351A (2013.06.12) discloses "three-way catalyst"; CN104254387A (2014.12.31, priority date 2012.04.27) published "filter substrate comprising three-way catalyst"; CN104334255A (2015.02.04, first 2012.06.06) published a "three-way catalyst system"; CN107206358A (2017.09.26, priority 2015.02.06) discloses "three-way catalyst and its application in exhaust system"; CN 107037A (2017.08.29, priority date 2015.01.19) published "double layer three-way catalyst with improved aging stability"; CN109153010A (2019.01.04, precedence date 2016.05.25) discloses "a three-way catalyst for purification of gasoline engine exhaust gas"; CN111491731A (2020.08.04, priority date 2018.02.22) discloses "three-way catalyst for exhaust gas purification" and the like. Wherein, the cerium-zirconium oxide accounts for 30 to 60 weight percent of the cerium-zirconium-aluminum-based oxide catalytic material.
The mixed cerium-zirconium-aluminum-based oxide catalytic material is prepared by neutralizing and precipitating a mixed solution of cerium salt, zirconium salt and aluminum salt with alkali, washing, drying and roasting. For example, patent CN101094810 (2007.12.26, priority 2004.12.30gb) discloses "a composite oxide for an automotive catalyst and comprising alumina and zirconia and optionally ceria"; CN1695798 (2005.11.16) discloses "cerium-zirconium-aluminum-based oxygen storage material and preparation method thereof"; CN101745375A (2010.06.23) discloses "cerium-zirconium-aluminum-based composite oxide material and preparation method thereof"; CN102824904A (2012.12.19) discloses an "aluminum cerium zirconium composite oxide catalytic material and a preparation method thereof"; CN103619468A (2014.03.05, priority 2011.07.01ep) discloses "ceria zirconia alumina compositions with enhanced thermal stability"; CN104226295A (2014.12.24) discloses "cerium-zirconium-aluminum composite oxide, gasoline vehicle exhaust three-way catalyst and their preparation methods"; CN109569566A (2019.04.05) discloses "cerium zirconium aluminum composite oxygen storage material and preparation method thereof"; CN110366445A (2019.10.22, preferentially 2016.12.23ep) discloses "anti-aging mixed oxides made of cerium, zirconium, aluminum and lanthanum for catalytic converters of motor vehicles"; CN110586145A (2019.12.20) discloses "a cerium-zirconium-aluminum composite material with high thermal stability, a preparation method and an application thereof". Wherein the cerium zirconium oxide accounts for about 30-60 wt% of the cerium zirconium aluminum based oxide catalytic material.
The mixed-soaking type cerium-zirconium-aluminum-based oxide catalytic material is prepared by soaking alumina microparticles in a mixed solution of cerium salt and zirconium salt, and performing alkali neutralization precipitation, washing, drying and roasting, or directly drying and roasting. Wherein part of cerium and zirconium salt is immersed in the inner holes of the alumina particles, part of the salt is outside the particles, and is agglomerated into hydroxide after being neutralized by alkali, and the mixture of part of cerium zirconium oxide particles and alumina particles containing part of cerium zirconium oxide is obtained after roasting. If the alumina is impregnated by the concentrated cerium and zirconium salt solution, more cerium and zirconium salt enter the pores in the alumina particles, part of the salt is outside the particles and is agglomerated into particles when being concentrated to the saturation solubility in the drying process, and the mixture of part of cerium-zirconium oxide particles and alumina particles containing more cerium-zirconium oxide is still obtained after roasting. In addition, when cerium nitrate or zirconium nitrate is used, NOx generation after firing causes pollution. The mixed-leaching type catalytic material has poor performance and is not frequently used.
The common problem of the above mixed, miscible and leaching cerium-zirconium-aluminum-based oxide catalytic materials is that if the amount of cerium-zirconium oxide is less than about 30wt% (the amount of aluminum oxide is greater than about 70 wt%), the thermal resistance of the catalytic material is favorable and the oxygen storage/release effect is not favorable, and it is difficult to effectively realize three-way catalysis; if the cerium zirconium oxide is used in an amount of more than about 30wt% (the amount of alumina is less than about 70 wt%), it is advantageous for the oxygen storage/release effect of the catalytic material but disadvantageous for the heat resistance, resulting in insufficient durability of the catalyst, i.e., "fish and bear paw cannot be used concurrently". Meanwhile, the catalytic materials are all micron particles, most of cerium zirconium oxide is wrapped in the micron particles, the utilization rate is low when the catalyst is used, and the rapid oxygen storage/release effect is difficult to play. The prior art at home and abroad at present is difficult to solve the problems, and technical innovation is urgently needed.
Disclosure of Invention
The invention aims to make up for the defects of the prior art and provides a cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material and a preparation method thereof, which are used for solving the problems that fish and bear palms cannot be obtained simultaneously and the rapid oxygen storage/release is difficult.
In order to achieve the purpose, the invention adopts the following technical scheme.
A cerium zirconium-aluminum-based oxide micro-nano composite catalytic material is formed by nano self-assembly of cerium zirconium oxide nano particles and active alumina micro particles, wherein the cerium zirconium oxide nano particles are dispersed and loaded on the surface of the outer layer of the active alumina micro particles to form a core-shell structure typeGranular micro-nano composite catalytic material and coating-shaped micro-nano composite catalytic material coated on substrate, marked as CeZrO @ Al 2 O 3 。
The raw material of the cerium-zirconium oxide nano-particles is aqueous dispersion nano-material sol, wherein the cerium-zirconium oxide is nano-particle single crystal, the nano-scale is 2-8 nm, the mass/volume percentage content in the sol is 1.0-20% (w/V), and the mass/volume percentage content is marked as Ce x Zr 1-x O 2 And x =0.0 to 1.0. The activated alumina is gamma-Al 2 O 3 Rare earth oxide stabilized Al 2 O 3 One or more than one of the compositions are polycrystal particles with the granularity of 0.1-25 mu m; in the cerium zirconium-aluminum based oxide micro-nano composite catalytic material, the cerium zirconium oxide accounts for 1.0 to 30 weight percent of the composite catalytic material, and the cerium zirconium oxide contains metal oxides, wherein the metal oxides comprise one or more of Ca, sr, ba, sc, Y, la, pr, nd and Sm oxides as an auxiliary agent, and the cerium zirconium-aluminum based oxide micro-nano composite catalytic material accounts for 0.0 to 20 weight percent of the catalytic material.
The preparation method of the cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material comprises the following steps.
(1) Preparation of micron-sized particulate alumina (Al) 2 O 3 ) The micron scale is 0.1-25 mu m, the specific surface area is 50-200 m 2 The catalyst comprises 0.0 to 10 weight percent of metal oxide auxiliary agent in mass percent.
(2) Synthesizing aqueous dispersion cerium zirconium oxide nano material sol, wherein the cerium zirconium oxide is nano particle single crystal with the nano size of 2-8 nm, the mass/volume percentage content in the sol is 1.0-20% (w/V) and is marked as Ce x Zr 1- x O 2 X =0.0 to 1.0; wherein the metal oxide auxiliary agent is contained and accounts for 0.0 to 10 weight percent of the mass of the oxide.
(3) And (3) mixing the alumina micron particle material prepared in the step (1) with the aqueous dispersion cerium-zirconium oxide nano material sol synthesized in the step (2) to generate slurry, drying and roasting to obtain the granular cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material, wherein the cerium-zirconium oxide accounts for 1.0-30 wt% of the composite catalytic material.
(4) And (4) coating the slurry generated in the step (3) or the granular cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material on a substrate after pulping, drying and roasting to obtain the coated cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material, wherein the substrate is a cordierite honeycomb ceramic substrate or an FeCrAl honeycomb metal substrate.
Wherein the drying in the step (3) is carried out at the temperature rising rate of 1-10 ℃/min from room temperature to 120 ℃ and is kept at the constant temperature for 1-3 h, the roasting is carried out at the constant temperature of 500-600 ℃ for 1-3 h, and then the temperature is reduced to room temperature; and (4) drying, namely heating the cerium zirconium-aluminum-based oxide micro-nano composite catalytic material from room temperature to 500 ℃ at the heating rate of 1-10 ℃/min, keeping the temperature of the roasting at the range of 500-1000 ℃ for 1-24 h, and then cooling to room temperature, wherein the solid content of the slurry in terms of the total amount of metal oxides is 30-50 g/100ml, and the coating amount of the cerium zirconium-aluminum-based oxide micro-nano composite catalytic material on a substrate is 50-300 g/L.
According to the cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material and the preparation method thereof, the cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material is used for manufacturing tail gas purification catalysts of fuel vehicles and fuel general engines and other industrial catalysts by loading one or more of noble metals Pt, pd, rh, au, ir and Ru.
Compared with the prior art, the invention has the following beneficial effects.
In the cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material, the dosage of the cerium-zirconium oxide is lower than 30wt%, the dosage of the aluminum oxide is higher than 70wt%, and the heat resistance of the aluminum oxide is greatly higher than that of the cerium-zirconium oxide, so that the heat resistance of the catalytic material can be greatly improved, and the durability of the catalyst is improved; on the other hand, as the cerium-zirconium oxide nano particles are dispersedly loaded on the surface of the outer layer of the alumina micro particles, the utilization rate is greatly improved, thereby improving the oxygen storage/release function and playing a role in rapidly storing/releasing oxygen. Therefore, the problem that fish and bear paw can not be obtained at the same time is solved, if the catalyst is used for purifying the tail gas of a gasoline car, the three-way catalysis can be effectively realized, and the durability of the catalyst is greatly improved.
Drawings
FIG. 1 a) is a schematic diagram of a cerium zirconium-aluminum based oxide micro-nano composite catalytic material prepared by the invention; b) Is a schematic diagram of a conventional mixed catalytic material of cerium zirconium-aluminum based oxide. Wherein CeZrO is Ce, zr and doped metal oxide, and AlO is Al and doped metal oxide.
Fig. 2 a) is a photoelectron spectroscopy (XPS) graph and a surface atomic concentration of the micro-nano composite catalytic material prepared in example 4 according to the embodiment of the present invention; b) A photoelectron spectroscopy (XPS) graph of the conventional mixed catalytic material prepared for comparative example 4 and its surface atomic concentration.
Fig. 3 a) is a Temperature Programmed Reduction (TPR) diagram of the micro-nano composite catalytic material prepared in example 5 in the specific embodiment of the present invention, and b) is a Temperature Programmed Reduction (TPR) diagram of the conventional hybrid catalytic material prepared in comparative example 5.
Detailed Description
The cerium-zirconium-aluminum based oxide micro-nano composite catalytic material and the preparation method thereof are further described by the following specific embodiment in combination with the attached drawings.
The cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material is formed by nano self-assembly of cerium-zirconium oxide nano particles and active alumina micro particles, wherein the cerium-zirconium oxide nano particles are dispersed and loaded on the outer layer surface of the active alumina micro particles to form a core-shell structure type granular micro-nano composite catalytic material, and a coating-shaped micro-nano composite catalytic material coated on a substrate and marked as CeZrO @ Al 2 O 3 . Wherein the alumina is a porous material which can be self-prepared or obtained from commercial products, and the particle size D90 (the particle size range of more than 90wt% by mass) is 0.1-25 μm, preferably 0.1-15 μm, and more preferably 0.5-10 μm; the specific surface area (BET method) is 50-200 m 2 Per g, preferably 100 to 180m after roasting at 600 ℃ for 5h 2 Per g, more preferably 140 to 160m 2 /g。
The preparation of alumina is known to be well established, such as precipitation and peptization. The precipitation method comprises reacting aluminum salt (such as aluminum nitrate and aluminum trichloride) solution with alkaline solution (such as ammonia water and sodium hydroxide solution) to generate precipitate, filtering, washing, pulping, drying, and spraying to obtain alumina precursor powder; glueThe dissolving method is to add pseudo-boehmite (AlO (OH)) into acid (such as dilute nitric acid) to form colloid, then prepare slurry, dry and spray the slurry to obtain alumina precursor powder. Drying the powder and roasting at about 500 ℃ to obtain gamma-Al 2 O 3 . In order to obtain gamma-Al with higher specific surface area 2 O 3 The addition of a certain amount of high polymer (such as polyethylene glycol and polyvinyl alcohol) in the spray slurry can play a role in pore-forming and increasing the specific surface area. gamma-Al 2 O 3 The specific surface area of the catalyst is rapidly reduced along with the rise of roasting or use temperature, and in order to increase the thermal stability of the catalyst, one or more of alkaline earth oxides or rare earth oxides such as Ca, sr, ba, sc, Y, la, pr, nd and Sm oxides can be doped as an auxiliary agent, and the content of the auxiliary agent is 0.0 to 10 weight percent; preferably oxides of higher atomic weight, more preferably Ba oxides and La oxides as doping aids, and in Al 2 O 3 In an amount of 1 to 8 wt.%, preferably 3 to 5 wt.%, to obtain a thermally stable alumina Al 2 O 3 The specific surface area can reach 140 to 160m after being roasted for 5 hours at 600 DEG C 2 (ii) in terms of/g. Further, gamma-Al 2 O 3 Or thermally stable Al 2 O 3 The particle size and the morphology of the particles are mainly related to the conditions of drying and spraying, and the required particle size and morphology are obtained by adjusting the spraying conditions.
The raw material of the cerium-zirconium oxide nano-particles is aqueous dispersion nano-material sol, wherein the cerium-zirconium oxide is nano-particle single crystals with the nano-scale of 2-8 nm, the mass percentage content in the sol is 1.0-20 wt%, and the mass percentage content is marked as Ce x Zr 1-x O 2 X =0.0 to 1.0; the cerium zirconium oxide composite material contains metal oxides, one or more of Ca, sr, ba, sc, Y, la, pr, nd and Sm oxides are used as an auxiliary agent, and the mass percentage of the cerium zirconium oxide is 0.0-10 wt%.
The synthesis method of cerium zirconium oxide aqueous dispersion nano material sol is characterized by applying the method disclosed in the invention patent CN 104591275B and making further improvement, and comprises the following steps: (1) Carrying out precipitation reaction on an inorganic salt aqueous solution of Ce and Zr and an inorganic alkali aqueous solution to prepare a Ce-Zr mixed hydroxide precipitate; (2) Heating and refluxing the Ce-Zr mixed hydroxide precipitate to prepare a Ce-Zr hydroxide eutectic; (3) Filtering and washing the Ce-Zr hydroxide eutectic to prepare Ce-Zr hydroxide hydrogel; (4) Mixing the Ce-Zr hydroxide hydrogel with aqueous solution of organic alcohols, organic acids and high polymers to prepare Ce-Zr oxide synthetic slurry; (5) Heating the Ce-Zr oxide synthetic slurry and carrying out one-step hydro-thermal synthesis to obtain aqueous medium dispersion cerium-zirconium oxide nano material sol, wherein the mass percentage of the cerium-zirconium oxide is 8-12 wt%; (6) And further evaporating and concentrating the sol, or diluting with water to obtain the cerium zirconium oxide with the mass percentage of 1.0-20 wt% in the sol.
To a specified composition Ce x Zr 1-x O 2 (x =0.0 to 1.0) Synthesis of nanomaterial by preparing and mixing aqueous solutions of inorganic salts of Ce and Zr, and diluting with water until the concentration of the total substance of Ce and Zr ions is 0.2 to 2.0mol · L -1 Preferably 0.5 to 1.0 mol.L -1 . Preparing an inorganic alkali aqueous solution, wherein the pH value of the precipitation reaction end point is 7-8 according to the amount of Ce salt and Zr salt; the volume of the inorganic alkali aqueous solution is equivalent to that of the inorganic salt aqueous solution of Ce and Zr, and the mass concentration of the inorganic alkali aqueous solution is 0.5-2.5 mol.L -1 Preferably 1.0 to 2.0 mol.L -1 。
The inorganic alkali aqueous solution and the inorganic salt aqueous solution of Ce and Zr are subjected to precipitation reaction under stirring, and positive single titration, reverse single titration or cocurrent titration can be adopted, wherein the titration end point pH is 7-10, and the preferred pH is 7-8. And carrying out precipitation reaction to obtain a suspension of the Ce-Zr mixed hydroxide precipitate. Before the precipitation reaction, a certain volume of hydrogen peroxide is added into the aqueous solution of the inorganic salts of Ce and Zr or the aqueous solution of inorganic alkalis, the amount of the added hydrogen peroxide is 0.5 to 2.0 times, preferably 0.6 to 1.0 times of that of the cerium, and the precipitate is brownish yellow.
In order to dope in the aqueous medium dispersion cerium zirconium oxide nano material, the selected water-soluble inorganic salt doped with metal is added into the inorganic salt aqueous solution of Ce and Zr to prepare a mixed aqueous solution, and then precipitation reaction is carried out. The doped metal comprises one or more of Ca, sr, ba, sc, Y, la, pr, nd and Sm, preferably one or more of Sc, Y, la, pr, nd and Sm, and the mass percentage of the oxide of the doped metal in the total oxide is 0.0-10 wt%.
Heating and stirring the Ce-Zr mixed hydroxide precipitate or M-doped mixed hydroxide precipitate suspension obtained by the precipitation reaction at 60 ℃, adding water-soluble organic alcohol to mix with the Ce and Zr mixed hydroxide precipitate suspension, then carrying out heating reflux treatment under stirring, wherein the heating reflux temperature is 90-105 ℃, carrying out reflux treatment for 1-8 h, preferably 2-5 h, and then cooling to room temperature to obtain the Ce-Zr hydroxide co-solution suspension. The volume of the added organic alcohol accounts for 0-30% of the total volume of the mixed solution, and the amount of the added organic alcohol ensures that the boiling temperature during reflux does not exceed 105 ℃.
Stirring and dispersing the Ce-Zr hydroxide codissolved suspension, then filtering, wherein the filtering mode can be suction filtration or filter pressing to remove inorganic impurities in the suspension, washing with pure water to be neutral, and the pH value of the filtrate is 6.9-7.2. After the last filtration, a Ce-Zr hydroxide hydrogel was obtained and maintained at a defined water content depending on the composition of Ce and Zr.
Adding water-soluble organic alcohol, organic acid and high polymer into the Ce-Zr hydroxide hydrogel, stirring at the constant temperature of between room temperature and 60 ℃ for 2 to 5 hours, mixing and dispersing to prepare Ce-Zr oxide synthetic slurry. Wherein the amount of added organic alcohols does not exceed the mass of the Ce-Zr oxide, preferably does not exceed 40% of the mass of the Ce-Zr oxide; the amount of the added high polymer is not more than the mass of the Ce-Zr oxide, and preferably not more than 30 percent of the mass of the Ce-Zr oxide; the amount of the organic acid added is not more than the amount of the Ce-Zr oxide, preferably not more than 70% of the amount of the Ce-Zr oxide. The Ce-Zr oxide nanoparticles are effectively dispersed through the synergistic effect of organic alcohols, organic acids and high polymers, so that the expected synthetic effect is obtained.
The Ce-Zr mixed hydroxide precipitate, the Ce-Zr hydroxide eutectic, the Ce-Zr hydroxide hydrogel and the Ce-Zr oxide synthetic slurry prepared by the steps are precursors, the preparation of each precursor influences the synthetic result, and the desired synthetic effect is obtained through the synergistic effect of the preparation steps.
Heating the Ce-Zr oxide synthetic slurry and stirring, wherein the heating temperature is room temperature to 80 ℃, keeping the temperature for 1 to 5 hours, preferably 40 to 60 ℃, keeping the temperature for 2 to 4 hours, and stirring to fully mix the synthetic slurry.
A hydrothermal synthesis mode is that the heated and mixed Ce-Zr oxide synthesis slurry is placed into a hydrothermal kettle, the temperature is raised to 120-220 ℃, the temperature is kept constant for 2-12 h, preferably 140-180 ℃, the temperature is kept constant for 2-8 h, and the aqueous medium dispersion cerium-zirconium oxide nano material is obtained. A hydrothermal synthesis mode is that the Ce-Zr oxide synthesis slurry is placed into a hydrothermal kettle, the temperature is raised to 120-200 ℃ at the heating rate of 0.2-2 ℃/min, the temperature is kept for 2-10 h, preferably at the heating rate of 0.5-1.0 ℃/min, the temperature is raised to 140-180 ℃, the temperature is kept for 2-6 h, and the aqueous medium dispersion cerium-zirconium oxide nano material is obtained.
The Ce-Zr mixed hydroxide precipitate, the Ce-Zr hydroxide eutectic, the Ce-Zr hydroxide hydrogel and the Ce-Zr oxide synthetic slurry obtained by the steps are all precursors, the preparation of each precursor influences the synthetic result, and the ideal synthetic effect is achieved through the synergistic effect of the preparation steps and the coupling effect with the hydrothermal synthesis step.
According to the above embodiment, aqueous medium-dispersed Ce is obtained x Zr 1-x O 2 Nanomaterial of which Ce is x Zr 1-x O 2 The mass (w/g) of the nano material accounts for 8 to 12 percent (w/V) of the volume (V/ml) of the nano material sol; preferably, the Ce can be evaporated and concentrated at a proper temperature, for example, 60-90 ℃ by heating, or concentrated by vacuumizing, and the Ce is concentrated during the concentration process x Zr 1-x O 2 The nano particles do not generate coagulation until the nano material sol becomes gel, ce x Zr 1-x O 2 The mass percentage of the (B) can reach more than 20 percent (w/V); preferably, it can be diluted with pure water, for example, with deionized water in an arbitrary ratio, and Ce is present during the dilution x Zr 1-x O 2 The nanoparticles do not generate coagulation, ce x Zr 1-x O 2 Is in mass percent ofThe amount may be less than 1% (w/V) or less.
In order to prepare the granular cerium zirconium-aluminum-based oxide micro-nano composite catalytic material, the prepared alumina micro-granular material is mixed with the synthesized aqueous dispersion cerium zirconium oxide nano material sol to generate slurry, and the slurry is dried and roasted to obtain the granular cerium zirconium-aluminum-based oxide micro-nano composite catalytic material. According to Ce in the sol x Zr 1-x O 2 Mass percentage of (B) and Ce x Zr 1-x O 2 The catalyst material is prepared and mixed to generate slurry, wherein the catalyst material accounts for 1.0 to 30 weight percent of the mass of the catalyst material; adding alumina into sol under stirring, or adding sol into alumina under stirring, or simultaneously adding alumina and sol under stirring to obtain paste-like slurry; heating, frying and drying the slurry, wherein the heating temperature is 30-90 ℃, preferably 40-80 ℃, more preferably 45-60 ℃, and slow frying is favorable for uniformly dispersing the nano particles on the surface of the micron carrier particles; then drying the mixture for 1 to 5 hours in a drying oven at the temperature of between 90 and 150 ℃, preferably drying the mixture for 2 to 3 hours at the temperature of between 100 and 130 ℃, sieving the dried mixture, heating the sieved mixture to the temperature of between 500 and 1000 ℃, and roasting the mixture for 1 to 5 hours to obtain the granular cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material.
In order to prepare the coated cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material, the prepared aluminum oxide micro-particle material is mixed with the synthesized aqueous dispersion cerium-zirconium oxide nano material sol to generate slurry, or the granular cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material is added into water to generate slurry in an emulsifying, shearing or ball-milling mode, wherein the solid content of the slurry in terms of the total amount of metal oxides is 20-60 g/100ml, preferably 30-50 g/100ml; coating the cordierite honeycomb ceramic matrix or FeCrAl honeycomb metal matrix with the slurry, wherein the coating amount of the cerium-zirconium-aluminum-based oxide on the matrix is controlled to be 50-300 g/L, preferably 100-200 g/L by manual coating, mechanical coating or automatic coating; heating the coated substrate from room temperature to 500 ℃ at the heating rate of 1-10 ℃/min for drying, then heating to 500-1000 ℃ and keeping the temperature for roasting for 1-24 h, wherein the specific drying, roasting temperature and time are determined according to specific application; then cooling to room temperature to obtain the coated cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material.
According to the cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material and the preparation method thereof, the cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material is used for manufacturing tail gas purification catalysts of fuel vehicles and fuel general engines and other industrial catalysts by loading one or more of noble metals Pt, pd, rh, au, ir and Ru.
One embodiment is a three-way catalyst for purifying the tail gas of a gasoline vehicle, and noble metals Pt, pd and Rh are loaded on the three-way catalyst. Taking a granular cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material, respectively soaking Pt, pd and Rh salts easily, drying, and roasting at the constant temperature of about 500 ℃ for 1-3 h to obtain catalysts respectively loaded with Pt, pd and Rh; then, the Pd catalyst is coated on the cordierite honeycomb ceramic substrate in a pulping way, and a first layer of coated catalyst is obtained after drying, constant temperature of 500 ℃ and roasting for 2-3 h; and then mixing, pulping and coating the Pt and Rh catalyst on the first layer of coating-shaped catalyst, drying, and roasting at the constant temperature of 550-600 ℃ for 2-3 h to obtain the three-way catalyst, wherein the use amounts of the Pt, pd and Rh and the coating amount of each catalyst are determined according to specific application. The three-way catalyst prepared by the method can effectively play a role in quickly storing/releasing oxygen and greatly improve the durability of the catalyst. The method can also be used for manufacturing tail gas purification catalysts of motorcycles, diesel vehicles, gas vehicles and fuel oil general engines, and the selection of the noble metal is determined according to specific application.
One embodiment is used for a space rocket propellant catalyst, and the noble metal Ir is loaded on the space rocket propellant catalyst. Taking a granular cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material, easily dipping Ir salt, drying, and roasting at a constant temperature of about 500 ℃ for 1-3 h to obtain an Ir-loaded catalyst; and then the Ir catalyst is coated on the millimeter particle carrier in a pulping way, and the coated catalyst is obtained after drying and roasting, so that the use amount of Ir can be greatly saved, and the cost is saved.
The noble metal supported catalyst is used in the fields of petrochemical industry, natural gas chemical industry, synthesis gas chemical industry, biomass chemical industry, pharmaceutical chemical industry and the like, zirconium-aluminum-based oxide micro-nano composite catalytic materials can be used, and the noble metal is selected according to specific application.
Specific examples the following examples are further illustrative of, but not limiting to, embodiments of the present invention, and any substitutions beyond those examples are intended to be within the scope of the embodiments of the present invention.
The performance detection of the cerium-zirconium-aluminum-based oxide catalytic material mainly comprises four types, namely detection of specific surface area, oxygen storage amount, surface performance and reduction performance.
The specific surface area reflects the capability of the catalytic material for dispersing the noble metal, and the higher the specific surface area of the material is, the better the effect of dispersing the noble metal is under the condition of a specified roasting time at a specified temperature. By low temperature N 2 Testing the specific surface area by an adsorption method (BET method), sieving a sample by a 40-60 mesh sieve, weighing 0.2g of the sample, placing the sample in a testing tube, pretreating at 300 ℃ for 3 hours, and then loading the sample into a nitrogen adsorption instrument for testing.
The oxygen storage amount reflects the oxygen storage/release capacity of the cerium-zirconium-aluminum-based oxide catalytic material. Taking 0.200g of sample, placing in a quartz tube (tube length 820mm, inner diameter 10), heating to 500 deg.C, keeping constant temperature, and introducing oxygen gas (containing O) of reaction gas 2 1.0V%, the remainder being N 2 ) With reducing gas (containing CO 2.0V%, the remainder being N) 2 ) At 300ml min -1 Alternately flowing through the reaction tube at a flow rate, separating reducing gas with gas chromatograph every 3.0min, converting into methane, and detecting CO with FID 2 The amount of (c); the reaction gas is continuously and alternately circulated for three times to obtain the average value of the test so as to obtain the measured CO 2 The amount of oxygen storage is calculated.
The surface performance comprises surface appearance and surface element concentration, the surface appearance of the coated catalytic material can be observed by a Scanning Electron Microscope (SEM), the surface element concentration is tested by photoelectron spectroscopy (XPS), and the higher the surface cerium concentration is, the better the rapid oxygen storage/release performance is.
Reduction performance reflects Ce in cerium-zirconium-aluminum-based oxide catalytic material +4 Reduction to Ce +3 The performance of the alloy is that the reduction temperature is lower, the low-temperature reduction performance is better, and a Temperature Programmed Reduction (TPR) method is adopted for testing.
Example 1
Preparing alumina by peptization method, wherein BaO and La are doped 2 O 3 The content of the oxide is 2wt% and 3wt% respectively, and the specific surface area is after roasting for 5h at 600 DEG C152m 2 ·g -1 The particle size D90 is 0.1-16 μm and is marked as Al 2 O 3 。
Synthesis of aqueous dispersed Ce 0.6 Zr 0.4 O 2 A nano material sol with a nano particle size of 5.2nm, ce 0.6 Zr 0.4 O 2 Is 10.0% (w/V) in mass/volume percentage, wherein Y is doped 2 O 3 、La 2 O 3 The contents are 0.2% (w/V) and 0.3% (w/V), respectively, and the metal oxide is designated CeZrO.
Taking 50ml of sol and 12.25g of alumina, mixing the sol and Al under stirring 2 O 3 Preparing slurry, wherein the solid content of the metal oxide is about 33% (w/V), heating, frying and drying the slurry at 60 ℃, then placing the slurry in a drying oven for drying at 120 ℃ for 3 hours, sieving to obtain a 40-60 mesh sample, heating the sample to 600 ℃ at room temperature for roasting for 5 hours, and heating to 1000 ℃ at room temperature for roasting for 5 hours to obtain the granular cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material, ceZrO and Al 2 O 3 The mass ratio of (2) is 30-70, and the measured specific surface area and oxygen storage amount are listed in the table I.
Example 2
The preparation method is the same as example 1, 50ml of sol and 21.00g of alumina are taken, and the solid content of the metal oxide in the prepared slurry is about 47 percent (w/V); ceZrO and Al are obtained 2 O 3 The mass ratio of (2) is 20-80, and the measured specific surface area and oxygen storage amount are listed in the table I.
Example 3
The preparation method is the same as example 1, 50ml of sol and 47.25g of alumina are taken, 43ml of deionized water is added into the sol to dilute the sol and then the sol is slurried with the alumina, and the solid content of metal oxide is about 50 percent (w/V); to obtain CeZrO and Al 2 O 3 The mass ratio of (2) is 10-90, and the specific surface area and oxygen storage are shown in Table I.
Comparative example 1
The alumina was prepared as in example 1. Conventional micron-particle oxygen storage material Ce 0.6 Zr 0.4 O 2 The preparation of (1) is carried out by coprecipitation, mixing solution of Ce and Zr salt (adding right amount of H) 2 O 2 ) Through concurrent flow titration with alkali liquor (ammonia solution) to generate precipitateFiltering and washing the precipitate to be neutral, adding a high polymer pore-forming agent, pulping, drying and spraying to obtain precursor powder; drying the powder, decomposing the high polymer, and roasting at 600 ℃ for 5h to obtain micron particle Ce 0.6 Zr 0.4 O 2 In which Y is doped 2 O 3 、La 2 O 3 Ce accounts for 0.6 Zr 0.4 O 2 In an amount of 2wt% and 3wt%, respectively, and a specific surface area of 74.6m 2 ·g -1 Oxygen storage amount is 205 mu mol O 2 ·g -1 The granularity D90 is 0.1-14 mu m; the metal oxide is designated CeZrO.
Taking Al 2 O 3 12.5g and CeZrO12.5g, adding deionized water, stirring to obtain slurry with the solid content of metal oxide being about 50% (w/V), heating, stir-frying and drying the slurry at 60 ℃, then placing the slurry in a drying oven for drying at 120 ℃ for 3 hours, sieving to obtain a sample with 40-60 meshes, heating the sample to 600 ℃ at room temperature for roasting for 5 hours, and heating the sample to 1000 ℃ at room temperature for roasting for 5 hours to obtain the granular cerium-zirconium-aluminum-based oxide micron mixed catalytic material, wherein CeZrO and Al are mixed with each other to obtain the granular cerium-zirconium-aluminum-based oxide micron mixed catalytic material 2 O 3 The mass ratio of (2) is 50-50, and the measured specific surface area and oxygen storage amount are listed in the table I.
Comparative example 2
The preparation method is the same as that of comparative example 1, wherein CeZrO is mixed with Al 2 O 3 The mass ratio of (2) is 40-60, and the measured specific surface area and oxygen storage amount are shown in the table I.
Comparative example 3
The preparation method is the same as that of comparative example 1, wherein CeZrO is mixed with Al 2 O 3 The mass ratio of (2) is 30-70, and the measured specific surface area and oxygen storage amount are listed in the table I.
Watch 1
Figure BDA0003378282970000081
The result shows that after roasting at 600 ℃ for 5 hours, the specific surface area of example 1 is higher than 27.1 percent compared with comparative example 1, and the oxygen storage capacity is higher than 32.7 percent; after roasting for 5 hours at 1000 ℃, the specific surface area of the example 1 is 32.3% higher than that of the comparative example 1, and the oxygen storage amount is higher than 35.1%, so that the thermal stability and the oxygen storage performance of the micro-nano composite catalytic material are greatly higher than those of the micro-micron mixed catalytic material.
Example 4
Synthesis of aqueous dispersed Ce 0.6 Zr 0.4 O 2 Nanomaterial colloids wherein Ce is 0.6 Zr 0.4 O 2 The mass/volume percentage content of (A) is 8.8% (w/V), la 2 O 3 The content was 0.44% (w/V). Taking 50ml of sol, commercial alumina (containing Al) 2 O 3 95wt% and the rest La and Pr) 26.2g, wherein the mass ratio of the metal oxide to the alumina in the sol is 15 | 85; adding 20ml of deionized water into the sol for dilution, and mixing the sol with alumina for pulping, wherein the solid content of metal oxide is about 40% (w/V); coating the slurry on a 400-pore cordierite honeycomb ceramic substrate with the coating amount of about 120g/L, heating the coated substrate from room temperature to 600 ℃ at the heating rate of 3 ℃/min, and roasting at the constant temperature for 2h to obtain the coated cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material, wherein CeO 2 The content was 9.7wt%. A4X 4mm piece of the coated substrate was analyzed by photoelectron spectroscopy (XPS), and as a result, the surface Ce concentration was 20.46% by mass as shown in FIG. 2 a).
Comparative example 4
Taking commercially available oxygen storage material (containing CeO) 2 33wt％、ZrO 2 62wt% of the balance La and Nd, 15.0g of commercial alumina (containing Al) 2 O 3 95wt%, the rest La and Pr) is 15.0g, the mass ratio is 50 | 50, and deionized water is added for mixing and pulping, the solid content of the metal oxide is about 40% (w/V); coating the slurry on a 400-pore cordierite honeycomb ceramic substrate with the coating amount of about 120g/L, and roasting the coated substrate at the constant temperature of 3 ℃/min from room temperature to 600 ℃ for 2h to obtain the coated cerium-zirconium-aluminum-based oxide micron mixed catalytic material, wherein CeO 2 The content was 16.5wt%. A4X 4mm piece of the coated substrate was analyzed by photoelectron spectroscopy (XPS), and the surface Ce concentration was 15.67% by mass as shown in FIG. 2 b).
Micro-nano composite catalytic material CeO 2 The content is 41.2 percent lower than that of the mixed catalytic material, and the mass concentration of Ce on the surface is higher than 31.4 percent, which indicates that the micro-nano composite catalytic material forms a nuclear shell structure type CeZrO @ Al 2 O 3 ，Al 2 O 3 The content and the mass concentration of Ce on the surface are greatly improved, so that the oxygen storage capacity, the rapid oxygen storage/release function and the thermal stability of the material are greatly improved or enhanced.
Example 5
The granular cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material roasted for 5 hours at the temperature of 600 ℃ in the example 1 is taken and subjected to a Temperature Programmed Reduction (TPR) test, the result is shown in the attached figure 3 a), the initial reduction temperature is lower, the reduction peak temperature is 573 ℃, and the peak type is narrower, so that the low-temperature reduction performance is better, and the rapid oxygen storage/release effect is facilitated.
Comparative example 5
The granular cerium-zirconium-aluminum-based oxide micron mixed catalytic material roasted for 5 hours at the temperature of 600 ℃ in the comparative example 1 is taken for carrying out a Temperature Programmed Reduction (TPR) test, the result is shown in the attached figure 3 b), the initial reduction temperature is higher, the reduction peak temperature is 622 ℃, the peak type is wider, and the low-temperature reduction performance is poor.
All test data of the present invention is not compared to any published patent, paper data or other literature data. Because the same index is tested, different testing methods are used in different laboratories, or the testing method is the same and the testing condition is different, or the testing condition is the same and the sample processing condition is different, the testing results are greatly different; even in the same laboratory, the same sample is tested by the same test method and test conditions, and the operation of different personnel can cause great errors.
The preparation method of the invention is easy to be industrially scaled up, and the process changes made in the process of scaling up do not constitute substantial innovation, thus still falling within the scope of protection of the claims of the invention.

Claims (7)

1. The cerium zirconium-aluminum-based oxide micro-nano composite catalytic material is characterized by consisting of cerium zirconium oxide nano particles and aluminum oxide micro particles, wherein the cerium zirconium oxide nano particles are dispersed and loaded on the surface of the outer layer of the aluminum oxide micro particles to form the micro-nano composite catalytic material with a core-shell structure, and the micro-nano composite catalytic material is marked as CeZrO @ Al 2 O 3 ；
The preparation method of the cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material comprises the following steps:
(1) Preparation of micron-sized alumina Al 2 O 3 The micron scale is 0.1-25µm, the specific surface area is 50-200 m 2 The catalyst comprises the following components in percentage by mass, wherein the catalyst contains a metal oxide auxiliary agent and accounts for 0-10 wt% of the oxide;
(2) Synthesizing aqueous dispersed cerium-zirconium oxide nano material sol, wherein the cerium-zirconium oxide is nano particle single crystal with the nano scale of 2-8 nm and the mass/volume percentage content in the sol of 1-20 percent, and the sol is marked as Ce x Zr 1-x O 2 X is more than 0 and less than 1, and the metal oxide auxiliary agent is contained and accounts for 0 to 10 weight percent of the oxide;
(3) Combining the alumina micron particle material prepared in the step (1) with the aqueous dispersion cerium-zirconium oxide nano material sol synthesized in the step (2) to generate slurry, drying and roasting to obtain the granular cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material;
the synthesis method of the aqueous dispersion cerium zirconium oxide nano material sol comprises the following steps:
a) Carrying out precipitation reaction on an inorganic salt aqueous solution of Ce and Zr and an inorganic alkali aqueous solution to prepare a Ce-Zr mixed hydroxide precipitate;
b) Heating and refluxing the Ce-Zr mixed hydroxide precipitate to prepare a Ce-Zr hydroxide eutectic;
c) Filtering and washing the Ce-Zr hydroxide eutectic to prepare Ce-Zr hydroxide hydrogel;
d) Mixing the Ce-Zr hydroxide hydrogel with aqueous solution of organic alcohols, organic acids and high polymers to prepare Ce-Zr oxide synthetic slurry;
e) Heating the Ce-Zr oxide synthetic slurry and carrying out one-step hydrothermal synthesis to obtain an aqueous dispersion cerium-zirconium oxide nano material sol, wherein the mass/volume percentage of the cerium-zirconium oxide is 8-12%;
f) And further evaporating and concentrating the sol, or diluting with water to obtain the cerium zirconium oxide with the mass/volume percentage content of 1-20% in the sol.
2. The cerium zirconium-aluminum based oxide micro-nano composite catalytic material of claim 1, wherein the cerium zirconium oxide accounts for 1-30 wt% of the composite catalytic material.
3. The cerium zirconium-aluminum based oxide micro/nano composite catalytic material of claim 1, wherein the metal oxides of the steps (1) and (2) comprise one or more of Ca, sr, ba, sc, Y, la, pr, nd, sm oxides as an auxiliary agent.
4. The cerium zirconium-aluminum based oxide micro-nano composite catalytic material of claim 1, wherein the drying in the step (3) is performed by heating from room temperature to 120 ℃ for 1-3 h at a heating rate of 1-10 ℃/min, and the baking is performed by heating from 500-600 ℃ for 1-3 h, and then cooling to room temperature.
5. The cerium zirconium aluminum based oxide micro/nano composite catalytic material according to any one of claims 1 to 4, comprising the cerium zirconium aluminum based oxide micro/nano composite catalytic material used as a particle-shaped cerium zirconium aluminum based oxide micro/nano composite catalytic material, a cerium zirconium aluminum based oxide micro/nano composite catalytic material in slurry and a coated cerium zirconium aluminum based oxide micro/nano composite catalytic material.
6. The cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material as claimed in any one of claims 1 to 4, which is characterized in that the cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material is used for manufacturing a fuel vehicle exhaust gas purification catalyst by loading one or more of noble metals of Pt, pd, rh, au, ir and Ru.
7. The cerium-zirconium-aluminum-based oxide micro-nano composite catalytic material as claimed in any one of claims 1 to 4, which is used for manufacturing a catalyst for purifying tail gas of a fuel engine by loading one or more of noble metals of Pt, pd, rh, au, ir and Ru.
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