High-oxygen-storage cerium-zirconium solid solution material and preparation method thereof

Abstract

The invention discloses a high-oxygen-storage zirconium solid solution material and a preparation method, and belongs to the technical field of rare earth catalytic materials, and the method comprises the following steps: precursor preparation, ultrasonic dispersion, double-gradient precipitation, ultrasonic aging, solid-liquid separation, three-section roasting and furnace cooling. Through the synergistic effect of double-gradient precipitation and ultrasonic aging, coarse grains and non-uniform particle size distribution are avoided, and the material is not prone to abnormal growth of the grains and structural collapse in long-term high-temperature service. Meanwhile, according to the gradient roasting process, through step-by-step regulation and control of crystal densification and crystal lattice reconstruction, separation of a fluorite phase and a pyrochlore phase easily occurring in traditional low-temperature single-section roasting is reduced, a stable crystal phase structure is maintained, it is ensured that the material can still keep sufficient active surface and pore channel structures under the working conditions of high temperature and thermal shock alternation, and the performance of the material is improved. The oxygen storage capacity and the long-term durability of the catalyst carrier are obviously improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rare earth catalytic materials, and particularly relates to a high-oxygen-storage cerium-zirconium solid solution material and a preparation method. BACKGROUND

[0002] As the core oxygen storage material of the three-way catalyst for automobile exhaust, the microstructure characteristics of cerium-zirconium solid solution, such as specific surface area, lattice defect concentration, and uniformity of doped elements, directly determine the dynamic purification efficiency of nitrogen oxides, hydrocarbons, and carbon monoxide. With the implementation of the national sixth and European seventh emission regulations, higher requirements are put forward for the high-temperature thermal stability and rapid oxygen release / storage capacity of catalytic materials.

[0003] However, the existing coprecipitation preparation technology has significant technical bottlenecks in key links. The kinetic control of the precipitant easily leads to grain coarsening. The traditional ammonia water precipitation method releases OH - from NH3·H2O to complete the coprecipitation of metal hydroxide, but the OH - release rate is significantly affected by temperature fluctuations. In the disclosed precipitation process, the sudden increase in the concentration of OH - leads to explosive nucleation of crystal nuclei, and the final product has coarse grains and uneven particle size distribution. Such coarse-grained materials have a large decrease in specific surface area after high-temperature air calcination aging, and cannot meet the requirements of related standards for the high-temperature durability of catalyst carriers.

[0004] The single calcination process easily causes phase separation and oxygen storage decay. The existing technology generally uses a low-temperature single-stage calcination process. Although this process can remove part of the organic matter, it cannot simultaneously achieve crystal densification and lattice oxygen vacancy construction. Specifically, the low-temperature single-stage calcination process can only partially eliminate the hydroxyl groups in the precursor. The residual mesoporous structure induces the phase separation of fluorite and pyrochlore phases at high temperatures. The lattice distortion at the phase interface leads to an increase in the oxygen vacancy migration barrier, and the oxygen storage capacity significantly decays, which severely restricts the rapid response capability of the catalyst under cold start conditions. The segregation of doped elements exacerbates high-temperature sintering. The current technology introduces yttrium and praseodymium stabilizers through mechanical mixing. However, due to the difference in ionic radius, the doped elements exhibit a gradient distribution in the lattice rather than a solid solution state. The element segregation leads to an increase in the grain boundary energy, and the grains abnormally grow under high-temperature thermal shock, resulting in a significant decrease in the specific surface area.

[0005] In addition, the difference in the thermal expansion coefficients between the local enrichment area of the doped elements and the main lattice induces microcracks, further accelerating the material powder failure. The above defects make it difficult for the existing cerium-zirconium materials to balance the contradiction between high specific surface area and high thermal stability under high-temperature, high-humidity, and thermal shock combined conditions, forcing catalyst manufacturers to compensate for performance decay by increasing the loading of noble metals, significantly increasing the cost.

[0006] Therefore, the present application designs a high-oxygen-storage cerium-zirconium solid solution material and a preparation method to solve the above problems. SUMMARY

[0007] In view of the above-mentioned shortcomings of the prior art, the present application provides a high-oxygen-storage ceria-zirconia solid solution material and a preparation method thereof.

[0008] To achieve the above object, the present application is implemented by the following technical solutions: The preparation method of the high-oxygen-storage ceria-zirconia solid solution material comprises the following steps: S1. Preparation of a precursor, zirconium salt, cerium salt, yttrium salt and praseodymium salt are mixed, the molar ratio of Ce / Zr is controlled at 1:1-1:2, the molar ratio of Y / Pr is 3:1-5:1, and the total doping amount of Y / Pr is 5-15wt%, deionized water is added to prepare a solution with a total metal ion concentration of 0.7-0.8mol / L, and polyepoxysuccinic acid sodium and polyvinylpyrrolidone with a mass ratio of 2.2-2.6:1 are added as dispersants, and the solution is stirred at 55-65℃ and 700-900rpm for 1-1.5h to obtain a precursor solution; S2. Ultrasonic dispersion, the precursor solution of S1 is ultrasonically treated at a frequency of 35-45kHz for 25-35min; S3. Double-gradient precipitation, in the first stage, the solution after ultrasonic treatment of S2 is placed at 58-62℃, a composite precipitant containing urea and ammonium bicarbonate is added at a rate of 1.8-2.2mL / min, the pH value is maintained at 8.7-8.9, and the reaction is maintained for 85-95min; In the second stage, the temperature is raised to 68-72℃, the composite precipitant is added at a rate of 4.8-5.2mL / min to maintain the pH value at 9.1-9.3, and the maintenance is performed for 25-35min to obtain a precipitate slurry; S4. Ultrasonic aging, the precipitate slurry is placed at 58-62℃, and is aged under ultrasonic power of 280-320W for 1.5-2.5h with microwave assistance, and a back pressure of 20-40kPa is applied during ultrasonic aging to obtain an aged slurry; S5. Solid-liquid separation, the aged slurry is centrifuged at 7500-8500rpm for 8-12min, washed with deionized water, and dried to obtain a precursor powder; S6. Three-stage calcination, the precursor powder is sequentially subjected to: Pre-calcination, the temperature is raised to 350-450℃ at a rate of 2-5℃ / min, and the temperature is maintained in an air atmosphere for 1.5-2.5h; Main calcination, the temperature is raised to 700-800℃ at a rate of 2-4℃ / min, and the temperature is maintained for 3-5h; Annealing, the temperature is raised to 900-1020℃ at a rate of 8-12℃ / min, and the temperature is maintained in an air atmosphere for 0.5-1.5h; After cooling to 400℃ at a rate of 10-15℃ / min, the temperature is cooled in the furnace.

[0009] Further, the dispersant in S1 is added in an amount of 0.15-0.28wt% of the total metal solution.

[0010] Further, the zirconium salt in S1 is used in an amount of 45-47g / 500mL water.

[0011] Further, the molar ratio of urea and ammonium bicarbonate in the composite precipitant in S3 is 1:1-3.

[0012] A high-oxygen-storage cerium-zirconium solid solution material prepared according to the preparation method of the high-oxygen-storage cerium-zirconium solid solution material.

[0013] Compared with the prior art, the present application has the following beneficial effects: 1. The present application avoids coarse grains and uneven particle size distribution through the synergistic effect of double-gradient precipitation and ultrasonic aging, so that the material is not prone to abnormal grain 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 step by step, reduces the separation of fluorite phase and pyrochlore phase that is prone to occur in traditional low-temperature single-stage calcination, maintains a stable crystal phase structure, and ensures that the material can still retain sufficient active surface and pore structure under high temperature and thermal shock alternating conditions, significantly improving the long-term durability of the catalyst carrier.

[0014] 2. The present application optimizes the crystal growth kinetics through the synergistic effect of double-rare earth doping and composite dispersant, solving the segregation problem of doping elements caused by ion radius difference in traditional mechanical mixing. The doping elements are uniformly distributed in the lattice, combined with the efficient oxygen vacancy network constructed by gradient calcination, enhancing the material's ability to store and release oxygen. This feature enables the material to quickly respond to the dynamic changes in oxygen concentration in the tail gas, flexibly adjusting the supply and consumption of oxygen between rich-oxygen and lean-oxygen environments, efficiently promoting the oxidation-reduction reactions of nitrogen oxides, hydrocarbons and carbon monoxide, especially in transient conditions such as cold start, which can quickly activate the catalytic reaction and improve the efficiency of pollutant purification.

[0015] 3. The present application ensures the stability and consistency of material performance by ensuring the precise controllability of process parameters, avoiding the problems of thermal expansion coefficient difference and micro-cracks caused by local enrichment of doping 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 noble metal loading. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0017] Figure 1 TEM image of the high-oxygen storage ceria-zirconia solid solution material prepared in Example 1; Figure 2 TEM image of the high-oxygen storage ceria-zirconia solid solution material prepared in Example 1 after aging at 1100℃ for 4h; Figure 3 XRD image of the high-oxygen storage ceria-zirconia solid solution material prepared in Example 1; Figure 4 XRD image of the high-oxygen storage ceria-zirconia solid solution material prepared in Example 2; Figure 5 XRD image of the high-oxygen storage ceria-zirconia solid solution material prepared in Example 3; Figure 6 XRD image of the high-oxygen storage ceria-zirconia solid solution material prepared in Example 4. DETAILED DESCRIPTION

[0018] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the drawings in the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort fall within the protection scope of the present application.

[0019] Embodiment 1: A preparation method of a high-oxygen storage ceria-zirconia solid solution material, comprising the following steps: S1: precursor preparation, mixing zirconium salt, cerium salt, yttrium salt and praseodymium salt, controlling the Ce / Zr molar ratio at 1:2, the Y / Pr molar ratio at 5:1, and the total Y / Pr doping amount at 15wt%, adding deionized water to prepare a solution with a total metal ion concentration of 0.7mol / L, adding 0.15wt% dispersant, the mass ratio of sodium polyepoxysuccinate to polyvinylpyrrolidone in the dispersant being 2.2:1, stirring at 55℃ and 700rpm for 1h to obtain a precursor solution; S2: ultrasonic dispersion, ultrasonically treating the precursor solution of S1 at a frequency of 35kHz for 25min; S3: double gradient precipitation, in the first stage, the solution after ultrasonic treatment in S2 is placed in a temperature of 58℃, a composite precipitant is added at a rate of 1.8 mL / min, the composite precipitant comprises urea and ammonium bicarbonate, the molar ratio of urea and ammonium bicarbonate in the composite precipitant is 1:1, the pH value is maintained at 8.7, and the reaction is maintained for 85 min; In the second stage, the temperature is increased to 68℃, the composite precipitant is supplemented at a rate of 4.8 mL / min to a pH of 9.1, and the maintenance is maintained for 25 min, to obtain a precipitate slurry; S4: ultrasonic aging, the precipitate slurry is placed in a temperature of 58℃, and is aged under ultrasonic power of 280W for 1.5h with microwave assistance (800W, 2.45GHz, 0.5h), a back pressure of 20kPa is applied during ultrasonic aging, to obtain an aged slurry; S5: solid-liquid separation, the aged slurry is centrifuged at a speed of 7500rpm for 8min, washed with deionized water until the conductivity is ≤80μS / cm, and dried to obtain a precursor powder; S6: three-stage calcination, the precursor powder is sequentially subjected to the following heat treatment: pre-calcination, the temperature is increased to 350℃ at a rate of 2℃ / min, and maintained in an air atmosphere for 1.5h; main calcination, the temperature is increased to 700℃ at a rate of 2℃ / min, and maintained for 3h;

[0020] annealing, the temperature is increased to 900℃ at a rate of 8℃ / min, and treated in an air atmosphere for 0.5h; cooled to 400℃ at a rate of 10℃ / min, and then cooled in the furnace. Embodiment 2: a preparation method of a high-oxygen-storage cerium-zirconium solid solution material, comprising the following steps: S1: precursor preparation, zirconium salt, cerium salt, yttrium salt and praseodymium salt are mixed, the molar ratio of Ce / Zr is controlled at 1:2, the molar ratio of Y / Pr is 3:1, and the total doping amount of Y / Pr is 5wt%, deionized water is added to prepare a solution with a total metal ion concentration of 0.8mol / L, 0.28wt% of a dispersant is added, the mass ratio of sodium polyepoxysuccinate to polyvinylpyrrolidone in the dispersant is 2.6:1, stirring is carried out at 65℃ and 900rpm for 1.5h, and a precursor solution is obtained; S2: ultrasonic dispersion, the precursor solution in S1 is ultrasonically treated at a frequency of 45kHz for 35min; S3: double gradient precipitation, in the first stage, the solution after ultrasonic treatment in S2 is placed in a temperature of 62℃, a composite precipitant is added at a rate of 2.2 mL / min, the composite precipitant comprises urea and ammonium bicarbonate, the molar ratio of urea and ammonium bicarbonate in the composite precipitant is 1:3, the pH value is maintained at 8.9, and the reaction is maintained for 95 min; The second stage is heated to 72°C, and the complex precipitant is added at a rate of 5.2 mL / min to pH 9.3, and maintained for 35 min to obtain a precipitate slurry; S4: ultrasonic aging, the precipitate slurry is placed in a temperature of 62°C, and is aged under ultrasonic power of 320 W for 2.5 h with microwave assistance (800 W, 2.45 GHz, 0.5 h), a back pressure of 40 kPa is applied during ultrasonic aging, and an aged slurry is obtained; S5: solid-liquid separation, the aged slurry is centrifuged at a speed of 8500 rpm for 12 min, washed with deionized water until the conductivity is less than or equal to 80 μS / cm, and dried to obtain a precursor powder; S6: three-stage calcination, the precursor powder is subjected to the following heat treatments in sequence: pre-calcination, heated to 450°C at a rate of 5°C / min, and maintained in an air atmosphere for 2.5 h; main calcination, heated to 800°C at a rate of 4°C / min, and maintained for 5 h; annealing, heated to 1020°C at a rate of 12°C / min, and treated in an air atmosphere for 1.5 h; cooled to 400°C at a rate of 15°C / min, and then cooled in the furnace.

[0021] Embodiment 3: a preparation method of a high-oxygen-storage ceria-zirconia solid solution material, comprising the following steps: S1: precursor preparation, zirconium salt, cerium salt, yttrium salt and praseodymium salt are mixed, the molar ratio of Ce / Zr is controlled to be 1:1.3, the molar ratio of Y / Pr is 4:1, and the total doping amount of Y / Pr is 10 wt%, deionized water is added to prepare a solution with a total metal ion concentration of 0.75 mol / L, 0.21 wt% of a dispersant is added, the mass ratio of sodium polyepoxysuccinate to polyvinylpyrrolidone in the dispersant is 2.4:1, and stirring is performed at 60°C and 850 rpm for 1.2 h; and a precursor solution is obtained; S2: ultrasonic dispersion, the precursor solution of S1 is subjected to ultrasonic treatment at a frequency of 40 kHz for 30 min; S3: double-gradient precipitation, the solution subjected to ultrasonic treatment in S2 is placed in a temperature of 60°C, and the complex precipitant is added at a rate of 2.0 mL / min, the complex precipitant comprises urea and ammonium bicarbonate, the molar ratio of urea to ammonium bicarbonate in the complex precipitant is 1:2, the pH value is maintained at 8.8, and the reaction is maintained for 90 min; The second stage is heated to 70°C, and the complex precipitant is added at a rate of 5.0 mL / min to pH 9.2, and maintained for 30 min to obtain a precipitate slurry; S4: ultrasonic aging, the precipitate slurry is placed in a temperature of 60°C, and is aged under an ultrasonic power of 300W for 1.8h with microwave assistance (800W, 2.45GHz, 0.5h), a back pressure of 35kPa is applied during the ultrasonic aging, and a post-aging slurry is obtained; S5: solid-liquid separation, the post-aging slurry is centrifuged at a rotating speed of 8000rpm for 10min, is washed with deionized water until the conductivity is less than or equal to 80μS / cm, and is dried to obtain a precursor powder; S6: three-stage calcination, the precursor powder is sequentially subjected to the following heat treatments: pre-calcination, the temperature is increased to 400°C at a rate of 3°C / min, and is maintained in an air atmosphere for 1.6h; main calcination, the temperature is increased to 750°C at a rate of 3°C / min, and is maintained for 4.2h; annealing, the temperature is increased to 1000°C at a rate of 11°C / min, and is treated in an air atmosphere for 1h; cooling to 400°C at a rate of 14°C / min and then furnace cooling.

[0022] Embodiment 4: a preparation method of a high-oxygen-storage ceria-zirconia solid solution material, comprising the following steps: S1: precursor preparation, zirconium salt, cerium salt, yttrium salt and praseodymium salt are mixed, the molar ratio of Ce / Zr is controlled to be 1:1.8, the molar ratio of Y / Pr is 4.2:1, the total doping amount of Y / Pr is 12wt%, deionized water is added to prepare a solution with a total metal ion concentration of 0.76mol / L, 0.23wt% of a dispersant is added, the mass ratio of sodium polyepoxysuccinate to polyvinylpyrrolidone in the dispersant is 2.5:1, and stirring is performed at 63°C and 820rpm for 1.3h; a precursor solution is obtained; S2: ultrasonic dispersion, the precursor solution of S1 is subjected to ultrasonic treatment at a frequency of 42kHz for 30min; S3: double-gradient precipitation, the solution after ultrasonic treatment of S2 is placed in a temperature of 58-62°C, a composite precipitant is added at a rate of 1.9mL / min, the composite precipitant comprises urea and ammonium bicarbonate, 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 maintained for 93min; in the second stage, the temperature is increased to 68-72°C, the composite precipitant is supplemented at a rate of 4.8-5.2mL / min to maintain the pH value at 8.9, and the maintenance is performed for 33min, and a precipitate slurry is obtained; S4: ultrasonic aging, the precipitate slurry is placed in a temperature of 60°C, and is aged under an ultrasonic power of 310W for 2.3h with microwave assistance (800W, 2.45GHz, 0.5h), a back pressure of 35kPa is applied during the ultrasonic aging, and a post-aging slurry is obtained; 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; S6: Three-stage calcination, the precursor powder is subjected to the following heat treatments in sequence: Pre-calcination: Heat to 420℃ at a rate of 5℃ / min and hold at that temperature in air for 2.1 hours. 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. Annealing: Heat to 1010℃ at 11℃ / min and treat in air atmosphere for 0.8h; Cooled to 400°C at a rate of 13°C / min, then cooled in the furnace.

[0023] Experimental Example 1: The high oxygen storage cerium-zirconium solid solution material prepared in Example 1 was characterized as follows.

[0024] 1.1 Transmission electron microscopy (TEM) analysis and testing; 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.

[0025] 1.2 X-ray diffraction (XRD) analysis and testing; SmartLab X-ray diffractometer (Cu Kα radiation, λ=0.15406 nm), scanning range 10-90° (2θ), step size 0.02°, scanning speed 5° / min; like Figures 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.

[0026] Experimental Example 2: Specific surface area test before and after aging; The initial specific surface area (BET) of the material was measured by using a TriStar II 3020 full-automatic specific surface area porosity analyzer (BET method) of American Micromeritics Company, under the test conditions of liquid nitrogen temperature (77K) and sample pretreatment temperature of 300℃ / 4h (high-purity N2purging).

[0027] The aging experiment was performed by using a muffle furnace (Nabertherm L5 / 11 type of Germany) with a temperature-programmed control, the temperature was raised at a rate of 5 (±0.5) ℃ / min to the target temperature (1000℃ / 1100℃), and the static air environment was maintained for 4 hours, and the specific surface area after aging at 1000℃ / 4h or 1100℃ / 4h was measured (the results are shown in the following table).

[0028] Experimental Example 3: Oxygen storage capacity test The oxygen storage capacity (μmol / g) was measured by using a SmartLab chemical adsorption instrument (TPD method) of Japan, at a temperature rising rate of 10 (±0.5) ℃ / min to 900℃, and the carrier gas was 5 (±0.1) % H2 / Ar mixed gas (flow rate of 30 (±0.5) mL / min).

[0029]

[0030] As shown in the above table, the high-oxygen-storage cerium-zirconium solid solution material prepared by the present application can still maintain a high specific surface area after high-temperature aging, which means that the grain sintering and structure collapse are effectively inhibited during long-term high-temperature service. This stability is derived from the optimized lattice structure and grain boundary characteristics inside the material, which inhibits abnormal grain growth and phase separation at high temperature, maintains sufficient active surface and pore structure, provides a stable place for catalytic reaction, and directly guarantees the long-term durability of the catalyst under high-temperature and thermal shock alternating working conditions such as automobile exhaust.

[0031] The high oxygen storage capacity reflects the significant improvement in the oxygen storage and release capacity of the material. This characteristic is derived from the synergistic effect of the efficient oxygen vacancy network and the doped elements in the material, which enables the material to quickly respond to the dynamic changes of the oxygen concentration in the exhaust gas, and flexibly adjust the supply and consumption of oxygen between the oxygen-rich and oxygen-poor environments, thereby efficiently promoting the oxidation-reduction reactions of nitrogen oxides, hydrocarbons and carbon monoxide. Especially in transient conditions such as cold start, the catalytic reaction can be quickly activated to improve the efficiency of pollutant purification.

[0032] The above examples are only used to illustrate the technical solutions of the present application, but not limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

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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