High-oxygen-storing ceria-zirconia solid solution material and preparation method thereof

Abstract

The application discloses a kind of high oxygen storage cerium zirconium solid solution materials and preparation method, belong to rare earth catalytic material technical field, the method includes the following steps: precursor preparation, ultrasonic dispersion, double gradient precipitation, ultrasonic aging, solid-liquid separation, three-stage calcination and cooling with furnace.The application avoids coarse grain and uneven particle size distribution through the synergistic effect of double gradient precipitation and ultrasonic aging, so that the material is not easy to occur grain abnormal growth and structure collapse in long-term high temperature service.At the same time, the gradient calcination process controls the crystal densification and lattice reconstruction by steps, reduces the separation of fluorite phase and pyrochlore phase which is easy to occur in traditional low temperature single-stage calcination, maintains the stable crystal phase structure, ensures that the material can still retain sufficient active surface and pore structure under high temperature, thermal shock alternating working condition, significantly improves the oxygen storage capacity and long-term durability of catalyst carrier.

Description

Technical Field

[0001] This invention relates to the field of rare earth catalytic materials technology, specifically to a high oxygen storage cerium-zirconium solid solution material and its preparation method. Background Technology

[0002] Cerium-zirconium solid solutions, as the core oxygen storage material in three-way catalytic converters for automotive exhaust, directly determine their dynamic purification efficiency for nitrogen oxides, hydrocarbons, and carbon monoxide due to their microstructural characteristics such as specific surface area, lattice defect concentration, and uniformity of dopant element distribution. With the implementation of China VI and Euro VII emission regulations, more stringent requirements have been placed on the high-temperature thermal stability and rapid oxygen release / storage capacity of catalytic materials.

[0003] However, existing co-precipitation methods have significant technical bottlenecks in key steps. Uncontrolled precipitant kinetics can easily lead to grain coarsening. Traditional ammonia precipitation methods release OH- through NH3·H2O. - The co-precipitation of metal hydroxides was completed, but its OH- - The release rate is significantly affected by temperature fluctuations. In publicly available precipitation processes, due to OH... - The sudden increase in concentration leads to explosive nucleation of crystal nuclei, resulting in coarse crystals with uneven particle size distribution in the final product. After high-temperature air calcination and aging, the specific surface area of ​​such coarse crystallized materials decreases significantly, failing to meet the relevant standards for the high-temperature durability of catalyst supports.

[0004] The simplification of the calcination process easily leads to phase separation and oxygen storage degradation. Existing technologies generally employ low-temperature single-stage calcination, which can remove some organic matter, but cannot simultaneously achieve crystal densification and lattice oxygen vacancy construction. Specifically, low-temperature single-stage calcination can only partially eliminate hydroxyl groups in the precursor. The remaining mesoporous structure induces phase separation between the fluorite and pyrochlore phases during high-temperature operation. Lattice distortion at the phase interface leads to an increase in the oxygen vacancy migration barrier, resulting in a significant decrease in oxygen storage capacity and severely restricting the catalyst's rapid response capability under cold-start conditions. Dopant element segregation exacerbates high-temperature sintering. Current technologies introduce stabilizers such as yttrium and praseodymium through mechanical mixing, but due to differences in ionic radii, the dopant elements exhibit a gradient distribution in the lattice rather than a solid solution state. Element segregation leads to an increase in grain boundary energy, resulting in abnormal grain growth under high-temperature thermal shock and a significant decrease in specific surface area.

[0005] Furthermore, the difference in thermal expansion coefficients between the local enrichment region of doped elements and the main lattice induces microcracks, further accelerating the pulverization failure of the material. These defects make it difficult for existing cerium-zirconium materials to balance the contradiction between high specific surface area and high thermal stability under combined conditions of high temperature, high humidity, and thermal shock. This forces catalyst manufacturers to compensate for performance degradation by increasing the loading of precious metals, significantly increasing their costs.

[0006] Based on this, the present invention designs a high oxygen storage cerium-zirconium solid solution material and its preparation method to solve the above problems. Summary of the Invention

[0007] In view of the above-mentioned shortcomings of the existing technology, the present invention provides a high oxygen storage cerium-zirconium solid solution material and its preparation method.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A method for preparing a high oxygen-storage cerium-zirconium solid solution material includes the following steps:

[0010] S1. Precursor preparation: Zirconium salt, cerium salt, yttrium salt, and praseodymium salt are mixed and prepared with Ce / Zr molar ratio controlled at 1:1-1:2, Y / Pr molar ratio at 3:1-5:1, and total Y / Pr doping amount at 5-15wt%. Deionized water is added to prepare a solution with a total metal ion concentration of 0.7-0.8mol / L. Sodium polyepoxysuccinate and polyvinylpyrrolidone are added as dispersants in a mass ratio of 2.2-2.6:1. The mixture is stirred at 55-65℃ and 700-900rpm for 1-1.5h to obtain the precursor solution.

[0011] S2. Ultrasonic dispersion: The precursor solution of S1 is ultrasonically treated at a frequency of 35-45kHz for 25-35min.

[0012] S3. Dual gradient precipitation: In the first stage, the solution after sonication in S2 is placed at 58-62℃, and a composite precipitant containing urea and ammonium bicarbonate is added dropwise at a rate of 1.8-2.2 mL / min. The pH value is maintained at 8.7-8.9, and the reaction is carried out for 85-95 min.

[0013] In the second stage, the temperature is raised to 68-72℃, and the composite precipitant is added at a rate of 4.8-5.2 mL / min until the pH value is 9.1-9.3, and maintained for 25-35 min to obtain the precipitated slurry.

[0014] S4. Ultrasonic aging: The precipitated slurry is placed at 58-62℃ and aged for 1.5-2.5 hours under ultrasonic power of 280-320W, with microwave assistance. A back pressure of 20-40kPa is applied during ultrasonic aging to obtain the aged slurry.

[0015] S5. Solid-liquid separation: Centrifuge the aged slurry at 7500-8500 rpm for 8-12 min, wash with deionized water, and dry to obtain precursor powder;

[0016] S6. Three-stage calcination, sequentially processing the precursor powder:

[0017] Pre-calcination: heat to 350-450℃ at a rate of 2-5℃ / min, and hold at that temperature in air for 1.5-2.5 hours.

[0018] For the main roasting, the temperature is increased to 700-800℃ at a rate of 2-4℃ / min, and held for 3-5 hours.

[0019] Annealing: Heat to 900-1020℃ at a rate of 8-12℃ / min, and treat in air atmosphere for 0.5-1.5h;

[0020] Cool to 400℃ at a rate of 10-15℃ / min and then cool with the furnace.

[0021] Furthermore, the amount of dispersant added in S1 is 0.15-0.28 wt% of the total metal solution.

[0022] Furthermore, the amount of zirconium salt used in S1 is 45-47g / 500mL of water.

[0023] Furthermore, the molar ratio of urea to ammonium bicarbonate in the composite precipitant of S3 is 1:1-3.

[0024] A high oxygen-storage cerium-zirconium solid solution material prepared according to the aforementioned method for preparing high oxygen-storage cerium-zirconium solid solution material.

[0025] Compared with the prior art, the beneficial effects of this invention are as follows:

[0026] 1. This invention utilizes the synergistic effect of dual-gradient precipitation and ultrasonic aging to avoid coarse grains and uneven particle size distribution, making the material less prone to abnormal grain growth and structural collapse during long-term high-temperature service. Simultaneously, the gradient calcination process, through stepwise control of crystal densification and lattice reconstruction, reduces the separation of fluorite and pyrochlore phases that easily occurs in traditional low-temperature single-stage calcination, maintaining a stable crystal phase structure. This ensures that the material retains sufficient active surface and pore structure under high-temperature and alternating thermal shock conditions, significantly improving the long-term durability of the catalyst support.

[0027] 2. This invention optimizes crystal growth kinetics through the synergistic effect of dual rare earth doping and composite dispersants, solving the segregation problem caused by differences in ionic radii of dopants in traditional mechanical mixing. The dopants achieve uniform distribution in the crystal lattice, and combined with the highly efficient oxygen vacancy network constructed by gradient calcination, enhance the material's ability to store and release oxygen. This characteristic allows the material to quickly respond to dynamic changes in oxygen concentration in exhaust gas, flexibly adjusting oxygen supply and consumption between oxygen-rich and oxygen-deficient environments. It efficiently promotes the redox reactions of nitrogen oxides, hydrocarbons, and carbon monoxide, especially under transient conditions such as cold start-up, rapidly activating catalytic reactions and improving pollutant purification efficiency.

[0028] 3. This invention ensures the stability and consistency of material properties by guaranteeing the precise controllability of process parameters, avoiding differences in thermal expansion coefficients and microcracks caused by local enrichment of dopant elements, and reducing the risk of material pulverization failure. This not only balances the contradiction between high specific surface area and high thermal stability, but also reduces the dependence on the amount of precious metal loading. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0030] Figure 1 The image shows a TEM image of the high oxygen storage cerium-zirconium solid solution material prepared in Example 1.

[0031] Figure 2 The image shows a TEM image of the high oxygen storage cerium-zirconium solid solution material prepared in Example 1 after aging at 1100℃ for 4 hours.

[0032] Figure 3 The image shows the XRD pattern of the high oxygen storage cerium-zirconium solid solution material prepared in Example 1.

[0033] Figure 4 The image shows the XRD pattern of the high oxygen storage cerium-zirconium solid solution material prepared in Example 2.

[0034] Figure 5 The image shows the XRD pattern of the high oxygen storage cerium-zirconium solid solution material prepared in Example 3.

[0035] Figure 6 The image shows the XRD pattern of the high oxygen storage cerium-zirconium solid solution material prepared in Example 4. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0037] Example 1: A method for preparing a high oxygen storage cerium-zirconium solid solution material, comprising the following steps:

[0038] S1: Precursor preparation: Zirconium salt, cerium salt, yttrium salt, and praseodymium salt were mixed and prepared with Ce / Zr molar ratio controlled at 1:2, Y / Pr molar ratio at 5:1, and total Y / Pr doping amount at 15wt%. Deionized water was added to prepare a solution with a total metal ion concentration of 0.7mol / L. 0.15wt% dispersant was added, with the mass ratio of sodium polyepoxysuccinate to polyvinylpyrrolidone in the dispersant being 2.2:1. The mixture was stirred at 55℃ and 700rpm for 1h to obtain the precursor solution.

[0039] S2: Ultrasonic dispersion, the precursor solution of S1 is ultrasonically treated at a frequency of 35kHz for 25min;

[0040] S3: Dual gradient precipitation. In the first stage, the solution after ultrasonic treatment of S2 is placed at a temperature of 58°C, and a composite precipitant is added dropwise at a rate of 1.8 mL / min. The composite precipitant contains urea and ammonium bicarbonate, and the molar ratio of urea to ammonium bicarbonate in the composite precipitant is 1:1. The pH value is maintained at 8.7, and the reaction is carried out for 85 min.

[0041] In the second stage, the temperature is raised to 68°C, and the composite precipitant is added at a rate of 4.8 mL / min until the pH reaches 9.1. This is maintained for 25 min to obtain the precipitated slurry.

[0042] S4: Ultrasonic aging. The precipitated slurry is placed at 58°C and aged for 1.5 hours at 280W ultrasonic power, with microwave assistance (800W, 2.45GHz, 0.5 hours). A back pressure of 20kPa is applied during ultrasonic aging to obtain the aged slurry.

[0043] S5: Solid-liquid separation: Centrifuge the aged slurry at 7500 rpm for 8 min, wash with deionized water until the conductivity is ≤80 μS / cm, and dry to obtain precursor powder;

[0044] S6: Three-stage calcination, the precursor powder is subjected to the following heat treatments in sequence:

[0045] Pre-calcination: Heat to 350℃ at a rate of 2℃ / min and hold at that temperature in air for 1.5 hours.

[0046] The main roasting process involves heating the temperature to 700℃ at a rate of 2℃ / min and holding it at that temperature for 3 hours.

[0047] Annealing: Heat to 900℃ at 8℃ / min and treat in air atmosphere for 0.5h;

[0048] Cooled to 400°C at a rate of 10°C / min, then cooled in the furnace.

[0049] Example 2: A method for preparing a high oxygen storage cerium-zirconium solid solution material, comprising the following steps:

[0050] S1: Precursor preparation: Zirconium salt, cerium salt, yttrium salt, and praseodymium salt were mixed and prepared with a Ce / Zr molar ratio of 1:2, a Y / Pr molar ratio of 3:1, and a total Y / Pr doping amount of 5wt%. Deionized water was added to prepare a solution with a total metal ion concentration of 0.8mol / L. 0.28wt% of dispersant was added, with a mass ratio of sodium polyepoxysuccinate to polyvinylpyrrolidone of 2.6:1. The mixture was stirred at 65℃ and 900rpm for 1.5h to obtain the precursor solution.

[0051] S2: Ultrasonic dispersion, the precursor solution of S1 is ultrasonically treated at a frequency of 45kHz for 35min;

[0052] S3: Dual gradient precipitation. In the first stage, the solution after ultrasonic treatment of S2 is placed at a temperature of 62℃, and a composite precipitant is added dropwise at a rate of 2.2mL / min. The composite precipitant contains urea and ammonium bicarbonate, and the molar ratio of urea to ammonium bicarbonate in the composite precipitant is 1:3. The pH value is maintained at 8.9, and the reaction is carried out for 95min.

[0053] In the second stage, the temperature is raised to 72°C, and the composite precipitant is added at a rate of 5.2 mL / min until the pH reaches 9.3. This is maintained for 35 min to obtain the precipitated slurry.

[0054] S4: Ultrasonic aging. The precipitated slurry is placed at 62°C and aged for 2.5 hours at 320W ultrasonic power, with microwave assistance (800W, 2.45GHz, 0.5 hours). A back pressure of 40kPa is applied during ultrasonic aging to obtain the aged slurry.

[0055] S5: Solid-liquid separation: Centrifuge the aged slurry at 8500 rpm for 12 min, wash with deionized water until the conductivity is ≤80 μS / cm, and dry to obtain precursor powder;

[0056] S6: Three-stage calcination, the precursor powder is subjected to the following heat treatments in sequence:

[0057] Pre-calcination: Heat to 450℃ at a rate of 5℃ / min and hold at that temperature in air for 2.5 hours.

[0058] The main roasting process involves heating the temperature to 800℃ at a rate of 4℃ / min and holding it at that temperature for 5 hours.

[0059] Annealing: Heat to 1020℃ at a rate of 12℃ / min and treat in air atmosphere for 1.5h;

[0060] Cooled to 400°C at a rate of 15°C / min, then cooled in the furnace.

[0061] Example 3: A method for preparing a high oxygen storage cerium-zirconium solid solution material, comprising the following steps:

[0062] S1: Precursor preparation: Zirconium salt, cerium salt, yttrium salt, and praseodymium salt were mixed and prepared with a Ce / Zr molar ratio of 1:1.3, a Y / Pr molar ratio of 4:1, and a total Y / Pr doping amount of 10wt%. Deionized water was added to prepare a solution with a total metal ion concentration of 0.75mol / L. 0.21wt% dispersant was added, with a mass ratio of sodium polyepoxysuccinate to polyvinylpyrrolidone of 2.4:1. The mixture was stirred at 60℃ and 850rpm for 1.2h to obtain the precursor solution.

[0063] S2: Ultrasonic dispersion, the precursor solution of S1 is ultrasonically treated at a frequency of 40kHz for 30min;

[0064] S3: Dual gradient precipitation. In the first stage, the solution after ultrasonic treatment of S2 is placed at a temperature of 60°C, and a composite precipitant is added dropwise at a rate of 2.0 mL / min. The composite precipitant contains urea and ammonium bicarbonate, and the molar ratio of urea to ammonium bicarbonate in the composite precipitant is 1:2. The pH value is maintained at 8.8, and the reaction is carried out for 90 min.

[0065] In the second stage, the temperature is raised to 70°C, and the composite precipitant is added at a rate of 5.0 mL / min until the pH reaches 9.2. This is maintained for 30 min to obtain the precipitated slurry.

[0066] S4: Ultrasonic aging. The precipitated slurry is placed at 60°C and aged for 1.8 hours at 300W ultrasonic power, with microwave assistance (800W, 2.45GHz, 0.5 hours). A back pressure of 35kPa is applied during ultrasonic aging to obtain the aged slurry.

[0067] S5: Solid-liquid separation: Centrifuge the aged slurry at 8000 rpm for 10 min, wash with deionized water until the conductivity is ≤80 μS / cm, and dry to obtain precursor powder;

[0068] S6: Three-stage calcination, the precursor powder is subjected to the following heat treatments in sequence:

[0069] Pre-calcination: Heat to 400℃ at a rate of 3℃ / min and hold at that temperature in air for 1.6 hours.

[0070] The main roasting process involves heating to 750℃ at a rate of 3℃ / min and holding at that temperature for 4.2 hours.

[0071] Annealing: Heat to 1000℃ at 11℃ / min and treat in air atmosphere for 1 hour;

[0072] It was cooled to 400°C at a rate of 14°C / min and then cooled in the furnace.

[0073] Example 4: A method for preparing a high oxygen storage cerium-zirconium solid solution material, comprising the following steps:

[0074] S1: Precursor preparation: Zirconium salt, cerium salt, yttrium salt, and praseodymium salt were mixed and prepared with a Ce / Zr molar ratio of 1:1.8, a Y / Pr molar ratio of 4.2:1, and a total Y / Pr doping amount of 12wt%. Deionized water was added to prepare a solution with a total metal ion concentration of 0.76mol / L. 0.23wt% dispersant was added, with a mass ratio of sodium polyepoxysuccinate to polyvinylpyrrolidone of 2.5:1. The mixture was stirred at 63℃ and 820rpm for 1.3h to obtain the precursor solution.

[0075] S2: Ultrasonic dispersion, the precursor solution of S1 was ultrasonically treated at a frequency of 42kHz for 30min;

[0076] S3: Dual gradient precipitation. In the first stage, the solution after ultrasonic treatment of S2 is placed at a temperature of 58-62℃, and a composite precipitant is added dropwise at a rate of 1.9mL / min. The composite precipitant contains urea and ammonium bicarbonate, and the molar ratio of urea to ammonium bicarbonate in the composite precipitant is 1:2.5. The pH value is maintained at 8.7, and the reaction is carried out for 93min.

[0077] In the second stage, the temperature is raised to 68-72℃, and the composite precipitant is added at a rate of 4.8-5.2 mL / min until the pH reaches 8.9. This is maintained for 33 min to obtain the precipitated slurry.

[0078] S4: Ultrasonic aging. The precipitated slurry is placed at 60°C and aged for 2.3 hours at 310W ultrasonic power, with microwave assistance (800W, 2.45GHz, 0.5 hours). A back pressure of 35kPa is applied during ultrasonic aging to obtain the aged slurry.

[0079] S5: Solid-liquid separation: Centrifuge the aged slurry at 7900 rpm for 11 min, wash with deionized water until the conductivity is ≤80 μS / cm, and dry to obtain precursor powder;

[0080] S6: Three-stage calcination, the precursor powder is subjected to the following heat treatments in sequence:

[0081] Pre-calcination: Heat to 420℃ at a rate of 5℃ / min and hold at that temperature in air for 2.1 hours.

[0082] The main roasting process involves heating the temperature to 780℃ at a rate of 5℃ / min and holding it at that temperature for 3 hours.

[0083] Annealing: Heat to 1010℃ at 11℃ / min and treat in air atmosphere for 0.8h;

[0084] Cooled to 400°C at a rate of 13°C / min, then cooled in the furnace.

[0085] Experimental Example 1: The high oxygen storage cerium-zirconium solid solution material prepared in Example 1 was characterized as follows.

[0086] 1.1 Transmission electron microscopy (TEM) analysis and testing;

[0087] The sample from Example 1 was observed using a JEM-2100F field emission transmission electron microscope (accelerating voltage 200kV). The results are as follows: Figure 1 As shown, the morphological characteristics are as follows: bright-field images show that the particles are spherical with a particle size distribution of 50-80 nm. High-resolution TEM images clearly show the (111) crystal plane (0.312 nm spacing) and (200) crystal plane (0.270 nm spacing). The electron microscope image of the high oxygen storage cerium-zirconium solid solution material prepared in Example 1 after aging at 1100 °C for 4 h is shown below. Figure 2 As shown.

[0088] 1.2 X-ray diffraction (XRD) analysis and testing;

[0089] SmartLab X-ray diffractometer (Cu Kα radiation, λ=0.15406 nm), scanning range 10-90° (2θ), step size 0.02°, scanning speed 5° / min;

[0090] like Figure 3-6 As shown, phase identification: the diffraction peak positions perfectly match the fluorite-type cubic phase (Fm-3m space group), and no monoclinic ZrO2 or CeO2 impurity peaks were detected; the cell parameter a = 0.5342 ± 0.0003 nm was obtained through Rietveld refinement, which is 1.27% smaller than that of pure CeO2 (a = 0.5411 nm), confirming that ZrO2... 4+ Successful solid solution was achieved.

[0091] Experimental Example 2: Specific surface area test before and after aging;

[0092] The initial specific surface area (BET) of the material was measured using a TriStar II 3020 fully automated specific surface area and porosity analyzer (BET method) from Micron Instruments, Inc., USA. The test conditions were liquid nitrogen temperature (77K) and sample pretreatment temperature of 300℃ / 4h (high-purity N2 purging).

[0093] Aging experiments were conducted using a muffle furnace (Nabertherm L5 / 11, Germany) with programmed temperature control. The heating rate was 5 (±0.5) °C / min to the target temperature (1000 °C / 1100 °C). The static air environment was maintained for 4 hours. The specific surface area after aging at 1000 °C / 4h or 1100 °C / 4h was measured (the results are shown in the table below).

[0094] Experiment Example 3: Oxygen Storage Capacity Test;

[0095] The oxygen storage capacity (μmol / g) was measured using a Rigaku SmartLab chemical adsorption analyzer (TPD method) with a heating rate of 10 (±0.5) °C / min to 900 °C and a carrier gas of 5 (±0.1)% H2 / Ar mixture (flow rate 30 (±0.5) mL / min).

[0096]

[0097] As shown in the table above, the high oxygen storage cerium-zirconium solid solution material prepared by this invention can still maintain a high specific surface area after high-temperature aging. This means that grain sintering and structural collapse are effectively suppressed during long-term high-temperature service. This stability stems from the optimized lattice structure and grain boundary characteristics within the material. By suppressing abnormal grain growth and phase separation at high temperatures, sufficient active surface and pore structure are maintained, providing a stable environment for catalytic reactions and directly ensuring the long-term durability of the catalyst under high-temperature and thermal shock conditions such as automotive exhaust.

[0098] The high oxygen storage capacity reflects the material's significantly enhanced ability to store and release oxygen. This characteristic stems from the synergistic effect of the highly efficient oxygen vacancy network constructed in the material and the doping elements, enabling the material to respond quickly to dynamic changes in oxygen concentration in the exhaust gas and flexibly adjust the supply and consumption of oxygen between oxygen-rich and oxygen-deficient environments. This efficiently promotes the redox reactions of nitrogen oxides, hydrocarbons, and carbon monoxide. Especially under transient conditions such as cold start, it can quickly activate catalytic reactions and improve the efficiency of pollutant purification.

[0099] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of preparing a high oxygen storage ceria-zirconia solid solution material, characterized by, Comprising the following steps: S1. Precursor preparation, mix zirconium salt, cerium salt, yttrium salt, praseodymium salt, control the Ce / Zr molar ratio at 1:1-1:2, Y / Pr molar ratio at 3:1-5:1, total Y / Pr doping amount at 5-15wt%, add deionized water to prepare a solution with a total metal ion concentration of 0.7-0.8mol / L, add polyepoxysuccinic acid sodium and polyvinylpyrrolidone as dispersants with a mass ratio of 2.2-2.6:1, stir at 55-65℃, 700-900rpm for 1-1.5h to obtain a precursor solution; S2. Ultrasonic dispersion, ultrasonically treat the precursor solution of S1 at a frequency of 35-45kHz for 25-35min; S3. Double gradient precipitation, in the first stage, place the ultrasonically treated solution of S2 at 58-62℃, add the composite precipitant at a rate of 1.8-2.2mL / min, the composite precipitant contains urea and ammonium bicarbonate, maintain the pH value at 8.7-8.9, react for 85-95min; In the second stage, increase the temperature to 68-72℃, supplement the composite precipitant at a rate of 4.8-5.2mL / min to a pH value of 9.1-9.3, maintain for 25-35min to obtain a precipitate slurry; S4. Ultrasonic aging, place the precipitate slurry at 58-62℃, ultrasonically age for 1.5-2.5h under a ultrasonic power of 280-320W, assist with microwave, and apply a back pressure of 20-40kPa during ultrasonic aging to obtain an aged slurry; S5. Solid-liquid separation, centrifuge the aged slurry at 7500-8500rpm for 8-12min, wash with deionized water, and dry to obtain a precursor powder; S6. Three-stage calcination, sequentially perform the following on the precursor powder: Pre-calcination, increase the temperature to 350-450℃ at a rate of 2-5℃ / min, maintain in air atmosphere for 1.5-2.5h; Main calcination, increase the temperature to 700-800℃ at a rate of 2-4℃ / min, maintain for 3-5h; Annealing, increase the temperature to 900-1020℃ at a rate of 8-12℃ / min, treat in air atmosphere for 0.5-1.5h; Cool to 400℃ at a rate of 10-15℃ / min, and then cool in the furnace.

2. The method of claim 1, wherein the high oxygen storage ceria-zirconia solid solution material is prepared by the method comprising: The amount of dispersant added in S1 is 0.15-0.28wt% of the total metal solution.

3. The method of claim 1, wherein the high oxygen storage ceria-zirconia solid solution material is prepared by the method comprising: The amount of zirconium salt used in S1 is 45-47g / 500mL water.

4. The method for preparing the high oxygen storage cerium-zirconium solid solution material according to claim 1, characterized in that, The molar ratio of urea to ammonium bicarbonate in the composite precipitant in S3 is 1:1-3.

5. A high-oxygen-storage cerium-zirconium solid solution material prepared by the preparation method of any one of claims 1-4.

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