CN116060016A

CN116060016A - Preparation method of oxygen storage material, oxygen storage material and application of oxygen storage material

Info

Publication number: CN116060016A
Application number: CN202211630021.2A
Authority: CN
Inventors: 杨彦鼎; 赵浩远; 熊芬; 陈超; 黄硕
Original assignee: Dongfeng Motor Corp
Current assignee: Dongfeng Motor Corp
Priority date: 2022-12-19
Filing date: 2022-12-19
Publication date: 2023-05-05

Abstract

The application relates to a preparation method of an oxygen storage material, which comprises the following steps: providing a solution A1 in which cerium salt, zirconium salt and macromolecule are dissolved, wherein the molar ratio of cerium atoms to zirconium atoms in the solution A1 is 0.3-0.8; dripping the A1 into a first alkaline solution, and reacting to obtain a solid-liquid mixture A2; providing a solution B1 in which cerium salt, zirconium salt and macromolecule are dissolved, wherein the molar ratio of cerium atoms to zirconium atoms in the solution B1 is 1.5-2.3; dropping the solution B1 into a second alkaline solution, and reacting to obtain a solid-liquid mixture B2; mixing the solid-liquid mixture A2, the solid-liquid mixture B2 and the surfactant to obtain a solid-liquid mixture C1, wherein the molar ratio of cerium atoms in the solid-liquid mixture A2 to cerium atoms in the solid-liquid mixture B2 is 1.2-3:1, a step of; reacting the solid-liquid mixture C1 to obtain a solid-liquid mixture C2; filtering the solid-liquid mixture C2 to obtain a filter cake, drying the filter cake, and roasting to obtain the oxygen storage material.

Description

Preparation method of oxygen storage material, oxygen storage material and application of oxygen storage material

Technical Field

The application relates to the field of automobile exhaust treatment, in particular to an oxygen storage material and a three-way catalyst.

Background

Automobile exhaust mainly comprises incomplete combustion Hydrocarbon (HC), CO generated by incomplete combustion, NOx generated by reaction, smoke particles, sulfides, formaldehyde and the like, and automobile exhaust control and management are hot spots and difficult problems of social concern for a long time, and higher requirements are put forward on an automobile exhaust aftertreatment module. Three-way catalysts (Three Way Catalysts, TWCs) are the core component of the exhaust aftertreatment module and convert CO, HC, and NOx in the exhaust to N ₂ 、CO ₂ And H ₂ Harmless substances such as O and the like are the most effective tail gas treatment measures at present. One key component of the three-way catalyst is an oxygen storage material which stores oxygen in a lean combustion state and releases oxygen in a rich combustion state, so that the operation window of the three-way catalyst is widened, and efficient and full conversion of CO, HC and NOx is realized.

The oxygen storage material commonly used at present is cerium-zirconium solid solution, and the high temperature resistance and the oxygen storage amount of the oxygen storage material are generally regulated and controlled by regulating the cerium-zirconium ratio in the prior art. In the commonly applied cerium-zirconium ratio range, the reduction of the cerium-zirconium ratio is beneficial to the increase of the high temperature resistance of the oxygen storage material, but if the oxygen storage amount needs to be increased, the cerium-zirconium ratio needs to be properly increased. Therefore, it is difficult to realize synchronous improvement of the high temperature resistance and the reserve of the oxygen storage material in the prior art.

Disclosure of Invention

The embodiment of the application provides a preparation method of an oxygen storage material, the oxygen storage material and a three-way catalyst, so as to solve the technical problem that the high temperature resistance and the reserve of the oxygen storage material are difficult to improve synchronously.

In a first aspect, embodiments of the present application provide a method for preparing an oxygen storage material, where the method for preparing an oxygen storage material includes the following steps:

providing a solution A1 in which cerium salt, zirconium salt and at least one polymer are dissolved, wherein the molar ratio of cerium atoms to zirconium atoms in the solution A1 is 0.3-0.8;

Dropwise adding the solution A1 into a first alkaline solution, and performing a first reaction at a first pH value and a first temperature to obtain a solid-liquid mixture A2;

providing a solution B1 in which cerium salt, zirconium salt and at least one polymer are dissolved, wherein the molar ratio of cerium atoms to zirconium atoms in the solution B1 is 1.5-2.3;

dropping the solution B1 into a second alkaline solution, and performing a second reaction at a second pH value and a second temperature to obtain a solid-liquid mixture B2;

mixing the solid-liquid mixture A2, the solid-liquid mixture B2 and the surfactant to obtain a solid-liquid mixture C1, wherein the molar ratio of cerium atoms in the solid-liquid mixture A2 to cerium atoms in the solid-liquid mixture B2 is 1.2-3:1, a step of;

subjecting the solid-liquid mixture C1 to a third reaction at a third pH and a third temperature to obtain a solid-liquid mixture C2;

filtering the solid-liquid mixture C2 to obtain a filter cake, drying the filter cake, and roasting to obtain the oxygen storage material.

In some embodiments of the present application, the drying of the filter cake followed by calcination comprises the steps of:

drying the filter cake;

pre-roasting the dried filter cake at 150-250 ℃;

carbonizing and roasting the pre-roasted filter cake in an inert gas atmosphere at 450-550 ℃;

And (3) heating and roasting the filter cake after carbonization and roasting at 600-800 ℃.

In some embodiments of the present application, a doping element salt is further dissolved in the solution A1, where the doping element in the doping element salt is at least one of an alkaline earth metal element and a transition metal element.

In some embodiments of the present application, the mass of the doping element salt dissolved in the solution A1 is 5% -15% of the mass of the cerium salt and the zirconium salt dissolved in the solution A1.

In some embodiments of the present application, the polymer dissolved in the solution A1 accounts for 30% -90% of the total mass of all salts dissolved in the solution A1.

In some embodiments of the present application, the polymer dissolved in the solution A1 is at least one of polyhydroxyethyl acrylate and polyhydroxyethyl methacrylate.

In some embodiments of the present application, the solution B1 also has a rare earth salt dissolved therein.

In some embodiments of the present application, the rare earth element in the rare earth salt is at least one of La, Y, pr, nd.

In some embodiments of the present application, the rare earth salt dissolved in the solution B1 is 5% -15% of the mass of the cerium and zirconium salts dissolved in the solution B1.

In some embodiments of the present application, the polymer dissolved in the solution B1 accounts for 20% -80% of the total mass of all salts dissolved in the solution B1.

In some embodiments of the present application, the polymer dissolved in the solution B1 is at least one of polyvinyl alcohol and polyethylene glycol.

In some embodiments of the present application, the polyvinyl alcohol has a degree of polymerization of no greater than 2000; and/or the number of the groups of groups,

the polymerization degree of the polyethylene glycol is not higher than 5000.

In some embodiments of the present application, the alkaline substance in the first alkaline solution comprises NH ₃ ·H ₂ O and NH ₄ HCO ₃ The method comprises the steps of carrying out a first treatment on the surface of the And/or the number of the groups of groups,

the alkaline substance in the second alkaline solution comprises NH ₃ ·H ₂ O、NH ₄ HCO ₃ At least one of them.

In some embodiments of the present application, the first pH is 8-10, the first temperature is 70-98 ℃, and the first reaction time is 2-4 hours; and/or the number of the groups of groups,

the second pH is 8-10, the second temperature is 60-90 ℃, and the second reaction time is 2-4h; and/or the number of the groups of groups,

the third pH value is 8-11, the third temperature is 60-90 ℃, and the third reaction time is 2-4h.

In some embodiments of the present application, the surfactant is at least one of potassium monolauryl phosphate, lauryl ether phosphate, cocomonoethanolamide, cocamidopropyl betaine, disodium lauriminodiacetate, nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether.

In a second aspect, embodiments of the present application provide an oxygen storage material, where the oxygen storage material is prepared by a method for preparing the oxygen storage material according to any one of the embodiments of the first aspect.

In a third aspect, embodiments herein provide a three-way catalyst comprising an oxygen storage material according to any of the embodiments of the second aspect.

In a fourth aspect, embodiments of the present application provide a gasoline engine exhaust gas aftertreatment module, where the gasoline engine exhaust gas aftertreatment module includes the oxygen storage material according to any one of the embodiments of the second aspect.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

according to the preparation method of the oxygen storage material, the oxygen storage material and the application thereof, two solutions with different molar ratios of cerium atoms and zirconium atoms are prepared, the two solutions are respectively pre-aged to prepare a solid-liquid mixture, then the solid-liquid mixture is mixed for further reaction, two-step aging of gel is carried out, and then roasting is carried out to form the oxygen storage material, and the obtained oxygen storage material has a low cerium-zirconium ratio solid solution main phase which is stable in structure and is not easy to sinter and agglomerate, and a high cerium-zirconium ratio second phase with excellent oxygen storage performance, so that the high temperature resistance and the oxygen storage capacity of the oxygen storage material can be improved simultaneously.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the description of the embodiments or the prior art will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

FIG. 1 is a schematic flow chart of a method for preparing an oxygen storage material according to an embodiment of the present disclosure;

fig. 2 is a schematic flow chart of baking after drying the filter cake according to the embodiment of the present application.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.

Unless specifically stated otherwise, the terms used herein should be understood as meaning as commonly used in the art. Thus, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. In case of conflict, the present specification will control.

Unless specifically indicated otherwise, the various raw materials, reagents, instruments, equipment, and the like used in this application are commercially available or may be prepared by existing methods.

The prior oxygen storage material has the technical problems that the high temperature resistance and the reserve are difficult to synchronously improve.

The technical scheme provided by the embodiment of the application aims to solve the technical problems, and the overall thought is as follows:

in a first aspect, an embodiment of the present application provides a method for preparing an oxygen storage material, referring to fig. 1, the method for preparing an oxygen storage material includes the following steps:

s1: providing a solution A1 in which cerium salt, zirconium salt and at least one polymer are dissolved, wherein the molar ratio of cerium atoms to zirconium atoms in the solution A1 is 0.3-0.8;

s2: dropwise adding the solution A1 into a first alkaline solution, and performing a first reaction at a first pH value and a first temperature to obtain a solid-liquid mixture A2;

S3: providing a solution B1 in which cerium salt, zirconium salt and at least one polymer are dissolved, wherein the molar ratio of cerium atoms to zirconium atoms in the solution B1 is 1.5-2.3;

s4: dropping the solution B1 into a second alkaline solution, and performing a second reaction at a second pH value and a second temperature to obtain a solid-liquid mixture B2;

s5: mixing the solid-liquid mixture A2, the solid-liquid mixture B2 and the surfactant to obtain a solid-liquid mixture C1, wherein the molar ratio of cerium atoms in the solid-liquid mixture A2 to cerium atoms in the solid-liquid mixture B2 is 1.2-3:1, a step of;

s6: subjecting the solid-liquid mixture C1 to a third reaction at a third pH and a third temperature to obtain a solid-liquid mixture C2;

s7: filtering the solid-liquid mixture C2 to obtain a filter cake, drying the filter cake, and roasting to obtain the oxygen storage material.

The solutions A1 and B1 are not limited to aqueous solutions, and may be, for example, alcohol solutions, mixed solutions of water and alcohol.

As an example, the solution A1 in which the cerium salt, the zirconium salt, and at least one polymer are dissolved as described herein may be prepared by:

s11: dissolving cerium salt and zirconium salt with the molar ratio of cerium atoms to zirconium atoms of 0.3-0.8 into deionized water to obtain cerium-zirconium salt solution;

S12: dissolving a polymer into ethanol or deionized water to obtain a polymer solution;

s13: and mixing the cerium-zirconium salt solution and the polymer solution to obtain a solution A1.

As an example, the solution B1 in which the cerium salt, the zirconium salt, and at least one polymer are dissolved as described herein may be prepared by:

s41: dissolving cerium salt and zirconium salt with the molar ratio of cerium atoms to zirconium atoms of 1.5-2.3 into deionized water to obtain cerium-zirconium salt solution;

s42: dissolving a polymer into ethanol or deionized water to obtain a polymer solution;

s43: and mixing the cerium-zirconium salt solution and the polymer solution to obtain a solution B1.

The solution A1 and the solution B1 each contain a polymer. The polymer has the function that after cerium and zirconium ions are precipitated in an alkaline environment to form solid particles in the subsequent step, the polymer can form steric hindrance among different solid particles to prevent the solid particles from agglomerating, so that the finally obtained cerium-zirconium solid solution, namely the oxygen storage material, has more refined structure, smaller size, larger specific surface area and stronger activity.

In step S2, the solution A1 is dropped into the first alkaline solution, and cerium and zirconium ions may be precipitated in an alkaline environment to form cerium and zirconium oxides by calcination in a subsequent step.

Similarly, in step S4, the solution B1 is added dropwise to the second alkaline solution, and cerium and zirconium ions may be precipitated in an alkaline environment to form cerium and zirconium oxides by calcination in a subsequent step.

In the step S1, the molar ratio of cerium atoms to zirconium atoms in the solution A1 is 0.3-0.8, so that solid particles in the solid-liquid mixture A2 can form cerium-zirconium solid solution with low cerium-zirconium ratio after roasting, namely the oxygen storage material has good high temperature resistance.

In the step S3, the molar ratio of cerium atoms to zirconium atoms in the solution B1 is 1.5-2.3, so that solid particles in the solid-liquid mixture B2 can form cerium-zirconium solid solution with high cerium-zirconium ratio after roasting, namely the oxygen storage material has good oxygen storage capacity.

In step S5, the molar ratio of the solid-liquid mixture A2 to the solid-liquid mixture B2 is 1.2-3:1, in the solid-liquid mixture C1, the solid particles having a low cerium-zirconium ratio are more and the solid particles having a high cerium-zirconium ratio are less, and further, the oxygen storage material having a low cerium-zirconium solid solution as a main phase and a high cerium-zirconium solid solution as a second phase is finally formed. The molar ratio of cerium ions in the two solid-liquid mixtures is in a proper range, and the balance of the high temperature resistance and the oxygen storage performance of the final oxygen storage material is also ensured.

In step S2 and step S4, the solution A1 and the solution B1 are reacted under the above conditions to form the solid-liquid mixture A2 and the solid-liquid mixture B2, respectively, and the solids in the solid-liquid mixture A2 and the solid-liquid mixture B2 are both present in the form of a gel, and the above reaction is essentially a gel formation and aging process. The process is marked as a first step of aging in the application, and forms a part of primary gel structure in the solution, so that two solutions respectively form two different cerium-zirconium-based precipitates in respective systems, and the two solutions respectively precipitate, on one hand, concentration averaging of the two solutions with different cerium-zirconium ratios in the subsequent mixing and secondary aging processes can be prevented, and a corresponding two-phase crosslinked network structure is difficult to form; on the other hand, the primary gel structure formed by the first aging step can play a role similar to a nucleation point in the second aging step, so that the energy barrier formed by the precursor is reduced.

In step S6, the solid-liquid mixture C1 is reacted under the above conditions to form a solid-liquid mixture C2, which is essentially a further aging process of the gel. This process is denoted herein as second step aging. The second aging step is similar to the aging process of the prior art, and the difference is that two different primary gel structures are formed in the system, and under the action of mechanical mixing and surfactant, the two primary gel structures can be fully dispersed and compounded, wherein the primary gel structures in the solid-liquid mixture A2 form the main phase of the final solid solution. In the second aging process, the cerium-zirconium salt solution which is not completely gelled in the two different solution systems is precipitated on the corresponding primary gel structure. In addition, the two-step aging process also effectively adjusts the problems of overlarge precipitation rate difference, uneven precipitation and the like caused by the difference of cerium-zirconium ratios and the different doping systems, and is beneficial to the regulation and control of the microstructure of the oxygen storage material.

Therefore, the first step and the second step of aging are carried out through the step S2, the step S4 and the step S6, so that the oxygen storage material taking cerium-zirconium solid solution with low cerium-zirconium ratio as a main phase and cerium-zirconium solid solution with high cerium-zirconium ratio as a second phase is more beneficial to be formed.

In practical application, the application can improve the high temperature resistance and the oxygen storage capacity of the oxygen storage material at the same time. The mechanism is that after the first step of aging, a gel network is formed preliminarily, the gel in the solid-liquid mixture A2 and the solid-liquid mixture B2 is not subjected to micro-level averaging of cerium-zirconium ratio and doping system, but the gel in the solid-liquid mixture A2 with relatively high mass is formed into a main gel network under the action of mechanical mixing and a surfactant, and the gel in the solid-liquid mixture B2 with relatively low mass is attached to the main gel network in the form of gel particles to form a double-phase gel network structure. After the diphase gel network structure is roasted, a double network structure which takes cerium-zirconium solid solution with low cerium-zirconium ratio as a main phase and cerium-zirconium solid solution with high cerium-zirconium ratio as a second phase can be formed, wherein the main phase has low cerium-zirconium ratio, the structure is stable, the sintering and agglomeration are not easy, and the high temperature resistance is good; the second phase cerium-zirconium ratio is high, the oxygen storage performance is excellent, and the second phase cerium-zirconium ratio is dispersed on a main phase with stable structure, and is not easy to sinter and agglomerate, so that the high temperature resistance and the oxygen storage capacity of the oxygen storage material can be improved simultaneously.

According to the preparation method, two solutions with different molar ratios of cerium atoms and zirconium atoms are prepared, the two solutions are respectively prepared into a solid-liquid mixture, then the solid-liquid mixture is mixed for further reaction, the two-step aging of the gel is carried out, and then the gel is roasted to form the oxygen storage material, so that the obtained oxygen storage material has a low cerium-zirconium ratio solid solution main phase which is stable in structure and is not easy to sinter and agglomerate, and a high cerium-zirconium ratio second phase which is excellent in oxygen storage performance, and the high temperature resistance and the oxygen storage capacity of the oxygen storage material can be improved simultaneously.

In addition, the preparation method has simple and convenient process flow and high production efficiency, can be introduced into the existing oxygen storage material production line, and has very good application prospect in the field of automobile exhaust treatment.

In some embodiments of the present application, the drying of the filter cake followed by calcination, please refer to fig. 2, comprises the steps of:

s71: drying the filter cake;

s72: pre-roasting the dried filter cake at 150-250 ℃;

s73: carbonizing and roasting the pre-roasted filter cake in an inert gas atmosphere at 450-550 ℃;

S74: and (3) heating and roasting the filter cake after carbonization and roasting at 600-800 ℃.

The present application performs multistage calcination on the filter cake. In step S72, the purpose of pre-baking is to shrink and dewater the polymer in the dual-phase gel network structure in advance, promote the pre-forming of the dual-network structure, prevent the polymer from being decomposed unevenly in the subsequent baking process, and form uneven pore structure in solid solution. In step S73 and step S74, the precursor structure is dehydrated and carbonized in the carbonization roasting and temperature-raising roasting processes, and the precursor structure is reacted into cerium-zirconium oxide or cerium-zirconium solid solution by hydroxide and carbonate, and the main purpose of the two steps of carbonization roasting and temperature-raising roasting is to regulate and control the transformation process and prevent the non-uniformity caused by rapid temperature raising.

In step S74, the filter cake may be baked at an elevated temperature in an inert gas or air atmosphere.

In some embodiments of the present application, steps S72-S74 are performed at a controlled gas flow rate, wherein the gas flow rate of step S72 is 100-200L/min and the gas flow rates of steps S73 and S74 are 200-400L/min.

The gas herein refers to the composition gas of the atmosphere in which the filter cake is located.

The purpose of controlling the gas flow rate is to prevent the structure from collapsing while taking away the roasted moisture.

The solution A1 is also dissolved with doping element salt, and corresponding doping elements can be doped in the oxygen storage material. The proper alkaline earth metal element or transition metal element oxide is added in the cerium-zirconium ratio range of the solution A1, so that on one hand, the solid solubility of the alkaline earth metal or transition metal oxide can be effectively improved, and the thermal stability of the cerium-zirconium solid solution is improved; on the other hand, due to the higher content of zirconium ions, alkaline earth metal or transition metal ions can form partial oxide with zirconium ions under the promotion of the high polymer in the solution A1, so that phase separation in the sintering and aging processes of cerium-zirconium oxide is inhibited.

The reason why the mass of the doped element salt is 5% -15% of the mass of the cerium salt and the zirconium salt in the solution A1 is that the oxide of the doped element in the range easily forms a stable solid solution with the cerium-zirconium oxide, and is embedded into the crystal of the cerium-zirconium oxide to prevent the crystal form transformation of the cerium-zirconium oxide under the high-temperature condition, so that the high-temperature resistance of the cerium-zirconium solid solution is improved.

In practical application, it is found that the hydroxyethyl polyacrylate and the hydroxyethyl polymethacrylate can realize good coating and size regulation of the precipitated particles under the cerium-zirconium ratio of the solution A1 and the two-step aging process conditions, and meanwhile, certain adhesion effect of the two substances to the precipitation in the solid-liquid mixture A2 is possible, so that the formation of a main gel network is facilitated.

In addition, in practical application, the polymer is at least one of poly (hydroxyethyl acrylate) and poly (hydroxyethyl methacrylate), and the main gel network is not easily damaged by the influence of the solid-liquid mixture B2 in the second aging process.

The solution B1 is also dissolved with rare earth salt, and the oxygen storage material can be doped with corresponding rare earth elements. Because the cerium ion content is higher in the cerium-zirconium ratio of the solution B1, the proper rare earth oxide is added, so that the void concentration in the cerium-zirconium oxide crystal can be increased, and the oxidation-reduction capability of tetravalent cerium ions and trivalent cerium ions can be improved, thereby improving the movement performance and oxygen storage performance of lattice oxygen.

The rare earth elements are selected to increase oxygen storage performance.

The rare earth salt has the beneficial effect that the mass of the rare earth salt is 5-15% of the mass of the cerium salt and the zirconium salt in the solution B1, and the oxygen storage performance can be improved higher in the range.

Polyethylene glycol (PEG) or polyvinyl alcohol (PVA) can be used as a dispersing agent to be adsorbed on the surfaces of solid particles, and when the adsorption layer reaches a certain thickness, enough repulsion can be generated to overcome the attraction between the particles, so that the dispersing effect is achieved. The molecular chains of PEG and PVA are in a snake shape in the aqueous solution, a large number of hydrophilic groups exist, and a strong hydrogen bond is easily established with the surface of hydroxide colloidal particles, so that a layer of macromolecular hydrophilic film is formed on the surface of the colloidal particles, and the steric hindrance effect is caused. The shielding effect of the polymer film reduces the Zeta potential slightly, and the sediment is uniformly dispersed. In the long-time water bath aging process, precipitated particles are extremely easy to ionize or adsorb one or OH-ions in a medium to generate electrostatic effect on the surface charge of the particles. The presence of non-bridging hydroxyl groups on the surface of these particles is also a major cause of agglomeration during the preparation process. Therefore, the surfactant PEG can be utilized to realize high electrostatic effect and steric hindrance effect among particles, so that electrostatic repulsive force among the particles is increased, non-bridging groups among the particles are thoroughly shielded, surface tension among the particles is reduced, and agglomeration among the particles is reduced.

the polymerization degree of the polyethylene glycol is not higher than 5000. Too high a degree of polymerization can result in coated particles that are too large to embed into the main gel frame, and are detrimental to the formation of the dual network structure.

The alkaline substance acts as a precipitant. In practical use, it was found that for solution A1, NH was used as ₃ ·H ₂ The precursor of the sample prepared by taking O as a precipitator is hydroxide precipitate, and the hard agglomeration phenomenon is easy to generate due to the hydroxy condensation in the thermal decomposition process, so that the sintering resistance of the sample is reduced. By NH alone ₄ HCO ₃ Samples prepared for precipitants also have poor thermal stability, probably due to NH ₄ HCO ₃ A large amount of carbonate precipitates are generated for the precipitant, OH-ions are not easy to adsorb on the surface, electrostatic repulsive force among particles is low, and agglomeration is easier. But with NH ₃ ·H ₂ O and NH ₄ HCO ₃ The mixture of (2) can play a good role as a precipitant. This is possible because of the NH ₃ ·H ₂ O and NH ₄ HCO ₃ The mixed solution is used as a precipitator to lead Ce ⁴⁺ And Zr (Zr) ⁴⁺ Ions are precipitated in the form of hydroxide and carbonate at the same time, and the decomposition temperature of the carbonate is far higher than that of the hydroxide, so that the precipitates are mutually influenced in the thermal decomposition process and are slowly decomposed, thereby effectively protecting the specific surface area and pore structure of the oxide and finally influencing the oxygen storage performance of the oxygen storage material.

Since solution A1 is the starting material for forming the main gel network, the rate of thermal decomposition of the precipitate formed subsequently to A1 is quite highThe requirement is that. Precipitant of solution B1 in NH ₃ ·H ₂ O and NH ₄ HCO ₃ The arbitrary selection of (3) does not have a significant effect on the performance of the oxygen storage material.

The surfactant is selected from the above reagents to help the combination of the two primary gel structures in the second aging process, and to protect the two structures from being destroyed and homogenized, thereby promoting the formation of the double network structure.

In a second aspect, embodiments of the present application provide an oxygen storage material, where the oxygen storage material is prepared by a method for preparing the oxygen storage material according to any one of the embodiments of the first aspect. The oxygen storage material is realized based on the preparation method of the oxygen storage material, and the specific implementation of the three-way catalyst can refer to the embodiment of the preparation method of the oxygen storage material.

In a third aspect, embodiments herein provide a three-way catalyst comprising an oxygen storage material according to any of the embodiments of the second aspect. The three-way catalyst is realized based on the oxygen storage material, and the specific implementation of the three-way catalyst can refer to the embodiment of the oxygen storage material.

In a fourth aspect, embodiments of the present application provide a gasoline engine exhaust gas aftertreatment module, where the gasoline engine exhaust gas aftertreatment module includes the oxygen storage material according to any one of the embodiments of the second aspect. The gasoline engine exhaust gas aftertreatment module is realized based on the oxygen storage material, and the specific implementation of the gasoline engine exhaust gas aftertreatment module can refer to the embodiment of the oxygen storage material.

The present application is further illustrated below in conjunction with specific embodiments. It should be understood that these examples are illustrative only of the present application and are not intended to limit the scope of the present application. The experimental procedures, which are not specified in the following examples, are generally determined according to national standards. If the corresponding national standard does not exist, the method is carried out according to the general international standard, the conventional condition or the condition recommended by the manufacturer.

Example 1

S01: 28.21g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 83.66g of Zr (NO) ₃ ) ₄ ·5H ₂ O, 3.57g of Fe (NO) ₃ ) ₃ And 3.57g of Ba (NO) ₃ ) ₂ Mixing and preparing into an aqueous solution to obtain a solution A1; 15.19g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 7.5g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 1.19g of La (NO) ₃ ) ₃ ·6H ₂ Mixing O and preparing into an aqueous solution to obtain a solution B1;

s02: preparing 47.6g of hydroxyethyl polyacrylate into an aqueous solution, adding the aqueous solution into the solution A1, and uniformly mixing to obtain a solution A11; preparing aqueous solution of polyvinyl alcohol with the polymerization degree of 1799 and the weight of 11.94g, and adding the aqueous solution into the solution B1 to obtain solution B11;

s03: drop solution A11 to NH ₃ ·H ₂ O and NH (NH) ₄ HCO ₃ The mass ratio is 1:1, adjusting the pH value of the solution to be 9.5, and then carrying out pre-aging reaction for 2 hours at 98 ℃ to obtain a solid-liquid mixture A2; dropwise adding the solution B11 to NH ₃ ·H ₂ In the O solution, adjusting and maintaining the pH=9.5 of the solution, and then carrying out pre-aging reaction for 2 hours at 70 ℃ to obtain a solid-liquid mixture B2;

s04: mixing the solid-liquid mixture A2 and B2 obtained in the step S03, adding cocamidopropyl betaine solution, stirring and mixing uniformly, adjusting the pH value of the solution to be 8, and aging at 90 ℃ for 6 hours to obtain a solid-liquid mixture C;

s05: and (3) carrying out suction filtration and washing on the obtained solid-liquid mixture C, drying and roasting a filter cake obtained by the suction filtration and washing, and finally obtaining the oxygen storage material, wherein the roasting step comprises the following steps:

s051, firstly, pre-roasting the dried filter cake in a nitrogen atmosphere, wherein the roasting temperature is 150 ℃, the roasting time is 2 hours, and the gas flow rate is 150L/min;

S052, then continuously carbonizing and roasting in nitrogen at 500 ℃ for 2h at the gas flow rate

300L/min;

s053, then heating and roasting in nitrogen or air, wherein the roasting temperature is 800 ℃, the roasting time is 3 hours, and the gas flow rate is 300L/min.

Example 2

S01: 23.87g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 47.19g of Zr (NO) ₃ ) ₄ ·5H ₂ O, 3.86g of Fe (NO) ₃ ) ₃ And 2.32g of Ca (NO ₃ ) ₂ Mixing and preparing into an aqueous solution to obtain a solution A1; 19.53g of Ce (NO) were weighed out separately ₃ ) ₃ ·6H ₂ O, 9.65g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 1.54g of La (NO) ₃ ) ₃ ·6H ₂ Mixing O and preparing into an aqueous solution to obtain a solution B1;

s02: preparing 23.17g of hydroxyethyl polyacrylate into an aqueous solution, adding the aqueous solution into the solution A1, and uniformly mixing to obtain a solution A11; preparing aqueous solution of polyvinyl alcohol with the polymerization degree of 1799 and the weight of 21.5g, and adding the aqueous solution into the solution B1 to obtain solution B11;

s03: drop solution A11 to NH ₃ ·H ₂ O and NH ₄ HCO ₃ The mass ratio is 1:1, adjusting the pH value of the solution to be 9.5, and then carrying out pre-aging reaction for 2 hours at 98 ℃ to obtain a solid-liquid mixture A2; dropwise adding the solution B11 to NH ₃ ·H ₂ In the O solution, adjusting and maintaining the pH=9.5 of the solution, and then carrying out pre-aging reaction for 2 hours at 70 ℃ to obtain a solid-liquid mixture B2;

300L/min;

Example 3

S01: 28.21g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 55.77g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 9.33g of Ba (NO) ₃ ) ₂ Mixing and preparing into an aqueous solution to obtain a solution A1; 15.19g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 9.76g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 2.77g of La (NO) ₃ ) ₃ ·6H ₂ Mixing O and preparing into an aqueous solution to obtain a solution B1;

s02: 46.66g of polyhydroxyethyl methacrylate is prepared into an aqueous solution, and the aqueous solution is added into the solution A1 to be uniformly mixed to obtain a solution A11; preparing aqueous solution of polyvinyl alcohol with the polymerization degree of 1799 and the weight of 11.09g, and adding the aqueous solution into the solution B1 to obtain solution B11;

300L/min;

Example 4

S01: 32.55g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 40.22g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 6.33g of Mn (NO) ₃ ) ₂ Mixing and preparing into an aqueous solution to obtain a solution A1; 10.85g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 6.97g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 1.55g of Y (NO) ₃ ) ₃ ·6H ₂ Mixing and preparing O into water-solubleObtaining a solution B1;

s02: preparing 47.46g of hydroxyethyl polyacrylate into an aqueous solution, adding the aqueous solution into the solution A1, and uniformly mixing to obtain a solution A11; preparing aqueous solution of polyvinyl alcohol with the polymerization degree of 1799 and the weight of 13.56g, and adding the aqueous solution into the solution B1 to obtain solution B11;

300L/min;

Example 5

S01: 23.87g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 29.49g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 2.81g of Ba (NO) ₃ ) ₂ Mixing and preparing into an aqueous solution to obtain a solution A1; 19.53g of Ce (NO) were weighed out separately ₃ ) ₃ ·6H ₂ O, 8.69g of Zr (NO) ₃ ) ₄ ·5H ₂ O, 0.58g of Y (NO) ₃ ) ₃ ·6H ₂ O and 0.29g Pr (NO) ₃ ) ₃ ·6H ₂ Mixing O and preparing into an aqueous solution to obtain a solution B1;

s02: preparing 22.47g of hydroxyethyl polyacrylate into an aqueous solution, adding the aqueous solution into the solution A1, and uniformly mixing to obtain a solution A11; preparing aqueous solution of polyvinyl alcohol with the polymerization degree of 1799 and the weight of 14.4g, and adding the aqueous solution into the solution B1 to obtain solution B11;

300L/min;

Example 6

This embodiment differs from embodiment 1 only in that:

step S02 is as follows:

s02: adding 47.6g of aqueous solution of polyvinyl alcohol with the polymerization degree of 1799 into the solution A1, and uniformly mixing to obtain a solution A11; polyvinyl alcohol having a polymerization degree of 1799 and a weight of 11.94g was prepared as an aqueous solution, and was added to the solution B1 to obtain a solution B11.

Example 7

This embodiment differs from embodiment 1 only in that:

step S03 is as follows:

s03: drop solution A11 to NH ₃ ·H ₂ In the O solution, adjusting the pH=9.5 of the solution, and then carrying out pre-aging reaction for 2 hours at 98 ℃ to obtain a solid-liquid mixture A2; dropwise adding the solution B11 to NH ₃ ·H ₂ In the solution O, the solution ph=9.5 was adjusted and kept, and then the pre-aging reaction was carried out at 70 ℃ for 2 hours to obtain a solid-liquid mixture B2.

Example 8

This embodiment differs from embodiment 1 only in that:

step S03 is as follows:

s03: drop solution A11 to NH ₄ HCO ₃ In the solution, adjusting the pH=9.5 of the solution, and then carrying out pre-aging reaction for 2 hours at 98 ℃ to obtain a solid-liquid mixture A2; dropwise adding the solution B11 to NH ₃ ·H ₂ In the solution O, the solution ph=9.5 was adjusted and kept, and then the pre-aging reaction was carried out at 70 ℃ for 2 hours to obtain a solid-liquid mixture B2.

Example 9

This embodiment differs from embodiment 1 only in that:

in step S05, the firing is not performed in advance. Specifically, the roasting step is as follows:

s051, carbonizing and roasting the dried filter cake in nitrogen at the roasting temperature of 500 ℃ for 2 hours, and obtaining gas

The volume flow rate is 300L/min;

s052, then heating and roasting in nitrogen or air, wherein the roasting temperature is 800 ℃, the roasting time is 3 hours, and the gas flow rate is 300L/min.

Comparative example 1

The difference between this comparative example and example 1 is that:

in this comparative example, the solution A1 and the solution B1 in step S01 were directly mixed, and the subsequent steps were adaptively adjusted. The method comprises the following steps:

s01: 28.21g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 83.66g of Zr (NO) ₃ ) ₄ ·5H ₂ O, 3.57g of Fe (NO) ₃ ) ₃ And 3.57g of Ba (NO) ₃ ) ₂ Mixing and preparing into an aqueous solution to obtain a solution A1; 15.19g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 7.5g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 1.19g of La (NO) ₃ ) ₃ ·6H ₂ O is mixed and prepared into an aqueous solution to obtain a solution B1, and the solution A1 is mixed with the solution B1 to obtain a solution A0;

s02: preparing 47.6g of hydroxyethyl polyacrylate into an aqueous solution, preparing 1799 of polyvinyl alcohol with the polymerization degree and the weight of 11.94g into the aqueous solution, and then adding the aqueous solution into the solution A0 to obtain a solution A01;

s03: dropping solution A01 into NH ₃ ·H ₂ O and NH ₄ HCO ₃ The mass ratio is 1:1, adjusting the pH value of the solution to be 9.5, and then carrying out pre-aging reaction for 2 hours at 98 ℃ to obtain a solid-liquid mixture A02;

s04: adding cocamidopropyl betaine solution into the solid-liquid mixture A02, stirring and mixing uniformly, adjusting the pH value of the solution to be 8, and aging for 6 hours at 90 ℃ to obtain a solid-liquid mixture C;

300L/min;

Comparative example 2

S01: 28.21g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 139.43g of Zr (NO) ₃ ) ₄ ·5H ₂ O, 5.47g of Fe (NO) ₃ ) ₃ And 9.11g of Ba (NO) ₃ ) ₂ Mixing and preparing into an aqueous solution to obtain a solution A1; 15.19g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 7.5g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 1.19g of La (NO) ₃ ) ₃ ·6H ₂ Mixing O and preparing into an aqueous solution to obtain a solution B1;

s02: preparing 72.89g of hydroxyethyl polyacrylate into an aqueous solution, adding the aqueous solution into the solution A1, and uniformly mixing to obtain a solution A11; preparing aqueous solution of polyvinyl alcohol with the polymerization degree of 1799 and the weight of 11.94g, and adding the aqueous solution into the solution B1 to obtain solution B11;

300L/min;

Comparative example 3

S01: 28.21g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 34.86g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 1.29g of Ba (NO) ₃ ) ₂ Mixing and preparing into an aqueous solution to obtain a solution A1; 15.19g of Ce (NO) was weighed out separately ₃ ) ₃ ·6H ₂ O, 15.02g of Zr (NO) ₃ ) ₄ ·5H ₂ O and 1.59g of La (NO) ₃ ) ₃ ·6H ₂ Mixing O and preparing into an aqueous solution to obtain a solution B1;

s02: preparing 16.09g of hydroxyethyl polyacrylate into an aqueous solution, adding the aqueous solution into the solution A1, and uniformly mixing to obtain a solution A11; preparing aqueous solution of polyvinyl alcohol with the polymerization degree of 1799 and the weight of 15.9g, and adding the aqueous solution into the solution B1 to obtain solution B11;

300L/min;

Comparative example 4

s02: dropwise adding the solution A1 to NH ₃ ·H ₂ O and NH ₄ HCO ₃ The mass ratio is 1:1, adjusting the pH value of the solution to be 9.5, and then carrying out pre-aging reaction for 2 hours at 98 ℃ to obtain a solid-liquid mixture A11; dropwise adding the solution B1 to NH ₃ ·H ₂ In the O solution, adjusting and maintaining the pH=9.5 of the solution, and then carrying out pre-aging reaction for 2 hours at 70 ℃ to obtain a solid-liquid mixture B11;

s03: mixing the solid-liquid mixture A11 and the solid-liquid mixture B11 obtained in the step S03, adding cocamidopropyl betaine solution, stirring and mixing uniformly, adjusting the pH value of the solution to be 8, and aging at 90 ℃ for 6 hours to obtain a solid-liquid mixture C;

s04: and (3) carrying out suction filtration and washing on the obtained solid-liquid mixture C, drying and roasting a filter cake obtained by the suction filtration and washing, and finally obtaining the oxygen storage material, wherein the roasting step comprises the following steps:

S051, firstly carbonizing and roasting the dried filter cake in a nitrogen atmosphere, wherein the roasting temperature is 500 ℃, the roasting time is 2 hours, and the gas flow rate is 300L/min;

Comparative example 5

This comparative example differs from example 1 only in that:

comparative example solution A11 and solutionB11 is added dropwise to NH at the same time ₃ ·H ₂ O and NH ₄ HCO ₃ The mass ratio is 1:1, rather than separate precipitation. The method comprises the following steps:

s03: solution A11 and solution B11 were simultaneously added dropwise to NH ₃ ·H ₂ O and NH ₄ HCO ₃ The mass ratio is 1:1, adjusting the pH value of the solution to be 9.5, and then carrying out pre-aging reaction for 2 hours at 98 ℃ to obtain a solid-liquid mixture C1; adding cocamidopropyl betaine solution, adjusting the pH value of the solution to be 8, and aging at 90 ℃ for 6 hours to obtain a solid-liquid mixture C2;

S04: and (3) carrying out suction filtration and washing on the obtained solid-liquid mixture C2, drying and roasting a filter cake obtained by suction filtration and washing, and finally obtaining the oxygen storage material, wherein the roasting step comprises the following steps:

s041, firstly, pre-roasting the dried filter cake in a nitrogen atmosphere, wherein the roasting temperature is 150 ℃, the roasting time is 2 hours, and the gas flow rate is 150L/min;

s042, continuously carbonizing and roasting in nitrogen at 500 ℃ for 2h at the gas flow rate

300L/min;

s043, then heating and roasting in nitrogen or air, wherein the roasting temperature is 800 ℃, the roasting time is 3 hours, and the gas flow rate is 300L/min.

The oxygen storage materials of each example and comparative example were divided into two parts, and one part was directly subjected to specific surface area characterization (noted: specific surface area before aging); the other part is subjected to aging treatment, namely high-temperature treatment at 1000 ℃, and the specific surface area is characterized (marked as the specific surface area after aging) after the aging treatment, wherein the characterization method is as follows: firstly, a sample is pretreated for 3 hours under the vacuum condition of 300 ℃, then high-purity N2 is used as adsorption gas, adsorption test is carried out under the liquid nitrogen of-196 ℃, desorption test is carried out under the liquid nitrogen of 25 ℃, and the specific surface area of the sample is calculated by adopting a BET method (Autosorb SI type full-automatic specific surface-aperture analyzer, quantachrome). Retention of specific surface area = specific surface area after aging/specific surface area before aging x 100%

The oxygen storage materials of each example and comparative example were divided into two parts, and one part was directly subjected to oxygen storage amount characterization (recorded as oxygen storage amount before aging); the other part is subjected to aging treatment, namely high-temperature treatment at 1000 ℃, and the oxygen storage quantity characterization (marked as the oxygen storage quantity after aging) is carried out after the aging treatment, and the test method is as follows: the sample powder was heated to 550 ℃ and purified in high purity H ₂ (20 ml/min) for 1h for sufficient reduction, and then the sample was cooled to 200℃in a stream of He (40 ml/min), and a fixed amount of high purity O was injected into the sample every 2min ₂ Until no O is detected ₂ Until consumption of (3). Obtaining O with time as abscissa and intensity as ordinate ₂ The pulse signal diagram can analyze the oxygen storage amount of the sample. Retention of oxygen storage = oxygen storage after aging/oxygen storage before aging x 100%.

The above experimental conditions and experimental results are shown in the following table:

TABLE 1 Structure and Performance index of oxygen storage materials prepared from examples and comparative examples

As can be seen from the data in table 1, the oxygen storage materials prepared in the examples have very high specific surface areas and oxygen storage amounts, and also have relatively low attenuation after aging at high temperatures. Wherein, for the embodiment, the retention rate of the specific surface area is not less than 45% after high-temperature aging, and the retention rate of the oxygen storage amount is not less than 60%; and for the comparative example, the retention rate of the specific surface area after high-temperature aging is not higher than 35%, and the retention rate of the oxygen storage amount is not higher than 50%. This illustrates that the embodiments 1-9 are effective in increasing the aging resistance of the oxygen storage material.

Example 1 an oxygen storage material was prepared by separately precipitating and aging two solutions having different ratios of cerium to zirconium, and comparative example 1 was performed by directly mixing the solution A1 with the solution B1 and then performing the subsequent steps, which corresponds to the case where only one solution was used in which the amounts of cerium and zirconium were the same as in example 1, and in this case, the specific surface area and the oxygen storage amount were significantly lower than in example 1. This demonstrates that the specific surface area and oxygen storage can be effectively increased by the technical means of respectively precipitating and aging the two solutions with different cerium-zirconium ratios in example 1.

The cerium-zirconium ratios of the two solutions of comparative examples 2 to 4, which do not satisfy the ranges set forth herein, were relatively significantly reduced in specific surface area, oxygen storage amount, and aging resistance in examples 1 to 9.

In comparison to example 1, the two solutions were added to the same alkali solution for precipitation, whereas example 1 separately precipitated and aged and then mixed for further aging. Ultimately, the specific surface area, oxygen storage amount and aging resistance of comparative example 5 were all significantly lower than those of example 1, and were substantially at the same level as comparative example 1. This demonstrates that the specific surface area, oxygen storage and aging resistance can be effectively increased by the technical means of respectively precipitating and aging two solutions with different cerium-zirconium ratios in example 1.

Example 6 differs from example 1 only in that the polyvinyl alcohol was used instead of hydroxyethyl polyacrylate in step S02, and as a result, the specific surface area, the oxygen storage amount and the aging resistance were reduced to some extent. This indicates that hydroxyethyl acrylate is a more preferred material.

Examples 7 and 8 differ from example 1 onlyIn step S03, a single NH is used ₃ ·H ₂ O solution and NH ₄ HCO ₃ Solution replacing NH ₃ ·H ₂ O and NH ₄ HCO ₃ As a result, the specific surface area, the oxygen storage amount and the aging resistance are reduced to some extent. This means that NH is selected ₃ ·H ₂ O and NH ₄ HCO ₃ Is a more preferred solution.

Example 9 differs from example 1 only in that: in step S05, the firing is not performed with pre-firing, and as a result, the specific surface area, the oxygen storage amount, and the aging resistance are reduced to some extent. This illustrates that pre-firing is a more preferred option.

Various embodiments of the present application may exist in a range format; it should be understood that the description in a range format is merely for convenience and brevity and should not be interpreted as a rigid limitation on the scope of the application. It is therefore to be understood that the range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that a description of a range from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, wherever applicable. In addition, whenever a numerical range is referred to herein, it is meant to include any reference number (fractional or integer) within the indicated range.

In this application, unless otherwise indicated, terms of orientation such as "upper" and "lower" are used specifically to refer to the orientation of the drawing in the figures. In addition, in the description of the present application, the terms "include", "comprise", "comprising" and the like mean "including but not limited to". Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element. Relational terms such as "first" and "second", and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Herein, "and/or" describing an association relationship of an association object means that there may be three relationships, for example, a and/or B, may mean: a alone, a and B together, and B alone. For the association relation of more than three association objects described by the "and/or", it means that any one of the three association objects may exist alone or any at least two of the three association objects exist simultaneously, for example, for a, and/or B, and/or C, any one of the A, B, C items may exist alone or any two of the A, B, C items exist simultaneously or three of the three items exist simultaneously. Herein, "at least one" means one or more, and "a plurality" means two or more. "at least one", "at least one" or the like refer to any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (individual) of a, b, or c," or "at least one (individual) of a, b, and c," may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple, respectively.

The foregoing is merely a specific embodiment of the application to enable one skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The preparation method of the oxygen storage material is characterized by comprising the following steps of:

2. The method for preparing an oxygen storage material according to claim 1, wherein the drying of the filter cake followed by calcination comprises the steps of:

drying the filter cake;

pre-roasting the dried filter cake at 150-250 ℃;

3. The method for preparing an oxygen storage material according to claim 1, wherein a doping element salt is further dissolved in the solution A1, and the doping element in the doping element salt is at least one of an alkaline earth metal element and a transition metal element.

4. The method of producing an oxygen storage material according to claim 3, wherein the mass of the doping element salt dissolved in the solution A1 is 5 to 15% of the mass of the cerium salt and the zirconium salt dissolved in the solution A1.

5. The method according to claim 4, wherein the polymer dissolved in the solution A1 accounts for 30% -90% of the total mass of all salts dissolved in the solution A1.

6. The method for producing an oxygen storage material according to claim 1, wherein the polymer dissolved in the solution A1 is at least one of polyhydroxyethyl acrylate and polyhydroxyethyl methacrylate.

7. The method for producing an oxygen storage material according to claim 1, wherein a rare earth salt is further dissolved in the solution B1.

8. The method for producing an oxygen storage material according to claim 7, wherein the rare earth element in the rare earth salt is at least one of La, Y, pr, nd.

9. The method for producing an oxygen storage material according to claim 7, wherein the mass of the rare earth salt dissolved in the solution B1 is 5% -15% of the mass of the cerium salt and the zirconium salt dissolved in the solution B1.

10. The method for preparing oxygen storage material according to claim 9, wherein the polymer dissolved in the solution B1 accounts for 20% -80% of the total mass of all salts dissolved in the solution B1.

11. The method for preparing an oxygen storage material according to claim 1, wherein the polymer dissolved in the solution B1 is at least one of polyvinyl alcohol and polyethylene glycol.

12. The method for producing an oxygen storage material according to claim 11, wherein the degree of polymerization of the polyvinyl alcohol is not higher than 2000; and/or the number of the groups of groups,

the polymerization degree of the polyethylene glycol is not higher than 5000.

13. The method for producing an oxygen storage material according to claim 1, characterized in that the alkaline substance in the first alkaline solution comprises NH ₃ ·H ₂ O and NH (NH) ₄ HCO ₃ The method comprises the steps of carrying out a first treatment on the surface of the And/or the number of the groups of groups,

14. The method for producing an oxygen storage material according to claim 1, wherein the first pH is 8 to 10, the first temperature is 70 to 98 ℃, and the time of the first reaction is 2 to 4 hours; and/or the number of the groups of groups,

15. The method for producing an oxygen storage material according to claim 1, wherein the surfactant is at least one of potassium monododecyl phosphate, lauryl ether phosphate, monoethanolamide cocoate, cocamidopropyl betaine, disodium lauriminodiacetate, polyoxyethylene nonylphenol ether, polyoxyethylene octylphenol ether.

16. An oxygen storage material, characterized in that the oxygen storage material is prepared by the preparation method of the oxygen storage material according to any one of claims 1 to 15.

17. A three-way catalyst comprising the oxygen storage material of claim 16.

18. A gasoline engine exhaust gas aftertreatment module comprising the oxygen storage material of claim 16.