A method for preparing nano cerium oxide particles and the obtained nano cerium oxide particles

Abstract

The application discloses a preparation method of nano cerium oxide particles and the obtained nano cerium oxide particles. The preparation method of the nano cerium oxide particles comprises the following steps: weighing Ce(NO3)3 . 6H2O is dissolved in methanol to obtain solution A; ammonia water is measured and added into the methanol to obtain solution B; solution A and solution B are mixed and stirred to react until the obtained reaction solution becomes purple; hydrogen peroxide is weighed and dissolved in the methanol to obtain solution C; the pH value of the reaction solution is controlled to be in an acidic range, solution C is added to perform an oxidation reaction until the reaction solution becomes yellow, and a mixed solution is obtained; centrifugation, washing and drying are performed to obtain the nano cerium oxide particles. The application further discloses the nano cerium oxide particles prepared by the preparation method. The primary particle size of the nano cerium oxide particles is within 2-8 nm, the particle size distribution is uniform, the nano cerium oxide particles are extremely easy to disperse in a moderate acidic aqueous phase, the dispersion is relatively stable when being stored and placed, the nano cerium oxide particles have higher application performance and a wider application range.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rare earth material synthesis. More particularly, it relates to a preparation method of nano ceria particles and the obtained nano ceria particles. BACKGROUND

[0002] As a rare earth oxide with excellent comprehensive performance, nano ceria is widely used in the fields of ultraviolet absorption, automobile exhaust purification, water pollution treatment, fuel cells, mechanical polishing, etc. There are many methods for synthesizing nano ceria, such as hydrothermal method, microemulsion method and sol-gel method, etc. These methods have complex process flow and are difficult to be used for industrialization. For example, the preparation process of the precipitation method is relatively simple, but the prepared nano ceria particles are easily agglomerated in water phase. Therefore, many studies add modifiers in the preparation process to realize the stable dispersion of nano ceria particles in water phase through steric hindrance effect and double electric layer repulsion.

[0003] The requirements for nano ceria particles are more stringent in fine and high-end fields. Although the surface modifier can improve the dispersion stability of nano ceria particles, it will affect the original performance of the material. Because in the application process, the surface grafted groups of the surface modified nano ceria particles may react with the applied material, thereby affecting the application performance. Surface modification can realize the dispersion stability of ceria in water phase, but at the same time, the groups modified on the surface of nano ceria particles also limit the application range of nano ceria particles.

[0004] In the existing research, there are few studies on improving the dispersion stability of nano ceria particles without using surface modifier. Therefore, it is necessary to provide a preparation method of high-purity water-dispersible nano ceria particles, so that the nano ceria particles can be widely used in more fields. SUMMARY

[0005] One object of the present application is to provide a preparation method of nano ceria particles and the obtained nano ceria particles. The surface of the nano ceria particles prepared by the preparation method does not have modified groups, which will not affect the original properties of the nano ceria, and will not react with other substances in the application process, thereby avoiding affecting the application performance of the material. The prepared nano ceria particles have high purity and water dispersibility.

[0006] Another object of the present application is to provide a nano ceria dispersion. The nano ceria dispersion only contains water and nano ceria particles, and has a pH value between 2 and 5, which belongs to moderate acidity. It has great application value in specific precision fields.

[0007] To achieve the above objects, the present application adopts the following technical solutions:

[0008] The present application provides a preparation method of nano cerium oxide particles, comprising the following steps:

[0009] weighing Ce(NO3)3 . 6H2O in methanol to obtain solution A;

[0010] measuring ammonia water and adding into methanol to obtain solution B;

[0011] mixing and stirring solution A and solution B to react until the reaction solution becomes purple;

[0012] weighing hydrogen peroxide and dissolving in methanol to obtain solution C;

[0013] controlling the pH value of the reaction solution to be in the acidic range, adding solution C to perform oxidation reaction until the reaction solution becomes yellow to obtain a mixed solution;

[0014] centrifuging, washing and drying the mixed solution to obtain nano cerium oxide particles.

[0015] Further, the mass fraction of Ce(NO3)3 . 6H2O in solution A is 6%-20%; the mass fraction of ammonia water in solution B is 11%-32%; the molar ratio of Ce(NO3)3 . 6H2O to ammonia water is 1:4-1:5, preferably, the molar ratio is 1:4.7.

[0016] Further, the mixing and stirring is mixing and stirring solution A into solution B.

[0017] Further, the reaction is water bath reaction, and the temperature is 60-70℃; preferably, the temperature is 65℃.

[0018] Further, the volume ratio of hydrogen peroxide to methanol is 1:1-1:19, preferably, the volume ratio is 1:9.

[0019] Further, the method for controlling the pH value of the reaction solution to be in the acidic range is increasing the ammonia gas volatilization speed by passing nitrogen gas to reduce the pH value of the reaction solution; or adding acid to reduce the pH value of the reaction solution.

[0020] Further, the acid is dilute nitric acid or hydrochloric acid; preferably, the acid is hydrochloric acid.

[0021] Further, the pH value acidic range is 1-6; preferably, the pH value acidic range is 1.89-5.53.

[0022] Further, weighing hydrogen peroxide and dissolving in methanol is slowly dropping hydrogen peroxide into methanol.

[0023] Further, the pH value of the mixed solution is in the range of 1-5; preferably, the pH value is in the range of 1.76-4.33.

[0024] Further, the centrifugation is performed at a speed of 5000-11000 rpm for 5-10 minutes; preferably, the centrifugation is performed at a speed of 5000 rpm for 5 minutes.

[0025] Further, the washing is performed by using anhydrous ethanol.

[0026] The nano cerium oxide particles prepared by the preparation method are also within the protection scope of the present application.

[0027] The present application further provides a preparation method of nano cerium oxide dispersion, which comprises dispersing the nano cerium oxide particles in water, filtering, and obtaining a yellow and clear nano cerium oxide dispersion.

[0028] Further, the dispersion method is ultrasonic dispersion.

[0029] The nano cerium oxide dispersion formed by the nano cerium oxide particles is also within the protection scope of the present application.

[0030] Further, the solid content of the nano cerium oxide dispersion is 1%-10%.

[0031] The present application has the following beneficial effects:

[0032] 1. The primary particle size of the nano cerium oxide particles prepared by the method of the present application is in the range of 2-8 nm, the particle size distribution is uniform, the nano cerium oxide particles are extremely easy to disperse in a moderately acidic aqueous phase, and the dispersion is relatively stable when stored at rest. The synthesis process is simple, the process time is relatively short, and the method is easy for industrial production, which endows the nano cerium oxide particles with higher application performance and a wider application range. The water-dispersed nano cerium oxide particles prepared without a surfactant and without high temperature have high purity, which reduces the adverse effects of chemical reactions of the groups on the surface of the nano cerium oxide particles in the application process; and the influence of the surface modifier on the properties of the nano cerium oxide particles is avoided.

[0033] 2. The nano cerium oxide dispersion prepared by the method of the present application only contains water and nano cerium oxide particles, the solid content is in the range of 1%-10%, the composition is simple, the purity is relatively high, and the nano cerium oxide dispersion can be applied in more fields. The pH value of the nano cerium oxide dispersion belongs to a moderate acidity of 2-5, and the nano cerium oxide dispersion has a great application value in specific precision fields. BRIEF DESCRIPTION OF DRAWINGS

[0034] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0035] Figure 1Photograph of the nanoceria dispersion prepared in Example 1.

[0036] Figure 2 XRD pattern of the nanoceria particles in the nanoceria dispersion prepared in Example 1.

[0037] Figure 3 TEM image and particle size distribution of the nanoceria particles in the nanoceria dispersion prepared in Example 1.

[0038] Figure 4 DLS particle size distribution of the nanoceria particles in the nanoceria dispersion prepared in Example 1.

[0039] Figure 5 TGA pattern of the nanoceria particles in the nanoceria dispersion prepared in Example 1.

[0040] Figure 6 TEM image and particle size distribution of the nanoceria particles in the nanoceria dispersion prepared in Example 2.

[0041] Figure 7 XRD pattern of the nanoceria particles in the nanoceria dispersion prepared in Example 3.

[0042] Figure 8 TEM image and particle size distribution of the nanoceria particles in the nanoceria dispersion prepared in Example 3.

[0043] Figure 9 XRD pattern of the nanoceria particles in the nanoceria dispersion prepared in Example 4.

[0044] Figure 10 TEM image and particle size distribution of the nanoceria particles in the nanoceria dispersion prepared in Example 4.

[0045] Figure 11 XRD pattern of the nanoceria particles in the nanoceria dispersion prepared in Example 5.

[0046] Figure 12 DLS particle size distribution of the nanoceria particles in the nanoceria dispersion prepared in Example 5.

[0047] Figure 13 TGA pattern of the nanoceria particles in the nanoceria dispersion prepared in Example 5.

[0048] Figure 14 XRD pattern and FT-IR pattern of the nanoceria particles in the nanoceria dispersion prepared in Example 6. DETAILED DESCRIPTION

[0049] In order to more clearly illustrate the present application, the present application will be further described below in conjunction with preferred embodiments and the accompanying drawings. Like components are denoted by the same reference numerals in the drawings. It should be understood by those skilled in the art that the specific description below is illustrative rather than limiting, and should not limit the scope of protection of the present application.

[0050] Preparation method of nanometer cerium oxide particles and obtained nanometer cerium oxide dispersion

[0051] 1. 5.08 g of Ce(N03)3·6H20 was weighed into 50 mL of methanol to obtain solution A; 4.1 mL of ammonia water was measured and added to 20 mL of methanol to obtain solution B; . 6H2O was dissolved in 50 mL of methanol to obtain solution A; 4.1 mL of ammonia water was measured and added to 20 mL of methanol to obtain solution B;

[0052] 2. A 250 mL three-necked flask was placed in a constant temperature water bath at 65°C, solution B was poured into the three-necked flask, and a digital electric stirrer was turned on to adjust the rotation speed to above 500 rpm to maintain the stirring intensity; then solution A was poured into the three-necked flask, and stirring reaction was carried out for 5 min until the obtained reaction liquid became purple;

[0053] 3. 1 mL of hydrogen peroxide solution was measured and dissolved in 9 mL of methanol to obtain solution C;

[0054] 4. The reaction liquid was filled with nitrogen for 6 min, the pH value was adjusted to 4.98, and solution C was slowly added dropwise until the reaction liquid became yellow, the stirring was stopped, and the temperature was lowered by standing to obtain a mixed liquid with a pH value of 4.33;

[0055] 5. The mixed liquid was centrifuged at 5000 r / min for 5 min to obtain yellow precipitate, which was washed twice with anhydrous ethanol and dried at 60°C for 12 h to obtain nanometer cerium oxide particles;

[0056] 6. The nanometer cerium oxide particles were dispersed in 50 mL of water, and a nanometer cerium oxide dispersion was obtained by passing through a filter, and the measured pH value was 2.78, and the actual picture is as shown in Figure 1 .

[0057] The nanometer cerium oxide dispersion obtained in this example was subjected to XRD test, TEM test, DLS particle size distribution test and TGA test, and the test results are as follows:

[0058] The XRD is as shown in Figure 2 , it can be seen that the nanometer cerium oxide particles in the nanometer cerium oxide dispersion obtained in this example are of fluorite structure and have good crystallinity; the TEM picture and the particle size distribution graph are as shown in Figure 3 ; and the DLS particle size distribution graph is as shown in Figure 4It can be seen from the figure that the average particle size of the nano cerium oxide particles in the nano cerium oxide dispersion obtained in this embodiment is 13 nm, and the PDI is 0.294; the TGA graph is as shown in the figure Figure 5 It can be seen from the figure that the purity of the nano cerium oxide particles in the nano cerium oxide dispersion obtained in this embodiment is 90.8%.

[0059] Preparation method of nano cerium oxide particles and nano cerium oxide dispersion obtained

[0060] 1. Take 2.54g of Ce(NO3)3 . 6H2O, dissolved in 50mL of methanol to obtain solution A; take 1.75mL of ammonia and add it to 17mL of methanol to obtain solution B;

[0061] 2. Place a 250mL three-necked flask in a constant temperature water bath at 65°C, pour solution B into the three-necked flask, and start the digital electric stirrer and adjust the speed to above 500rpm to maintain the stirring intensity; then pour solution A into the three-necked flask, stir for 5min, and until the reaction liquid turns purple;

[0062] 3. Take 1mL of hydrogen peroxide and dissolve it in 19mL of methanol to obtain solution C;

[0063] 4. Add 0.4mL of concentrated hydrochloric acid to the reaction liquid to adjust the pH value to 1.89, slowly add solution C for oxidation reaction until the reaction liquid turns yellow, stop stirring, and stand to cool down to obtain a mixed liquid with a pH value of 1.76;

[0064] 5. Centrifuge the mixed liquid at 5000r / min for 5min to obtain yellow precipitate, wash it with anhydrous ethanol twice, and dry it at 60°C for 12h to obtain nano cerium oxide particles;

[0065] 6. Disperse the nano cerium oxide particles in 50mL of water, pass through a filter to obtain a nano cerium oxide dispersion, and measure the pH value to be 2.80.

[0066] TEM test is performed on the nano cerium oxide dispersion obtained in this embodiment, and the test results are as follows: the TEM picture and the particle size distribution graph are as shown in the figure Figure 6 It can be seen from the figure that the primary particle size of the nano cerium oxide particles in the nano cerium oxide dispersion obtained in this embodiment is 2-8nm.

[0067] Preparation method of nano cerium oxide particles and nano cerium oxide dispersion obtained

[0068] 1. Take 2.54g of Ce(NO3)3 . 6H2O, dissolved in 50mL of methanol to obtain solution A; take 1.75mL of ammonia and add it to 17mL of methanol to obtain solution B;

[0069] 2. Put a 250 mL three-necked flask in a constant temperature water bath at 65°C, pour solution B into the three-necked flask, and start a digital electric stirrer, and adjust the rotating speed to be above 500 rpm to keep the stirring intensity; then pour solution A into the three-necked flask, and stir for 5 min until the reaction solution becomes purple;

[0070] 3. Measure 1 mL of hydrogen peroxide solution in 9 mL of methanol to obtain solution C;

[0071] 4. Add 0.7 mL of concentrated hydrochloric acid to the reaction solution to adjust the pH value to 4.96, and slowly drop solution C for oxidation reaction until the reaction solution becomes yellow, stop stirring, and stand to cool down, to obtain a mixture solution with a pH value of 3.96;

[0072] 5. Centrifuge the mixture solution at 5000 r / min for 5 min, wash the yellow precipitate with anhydrous ethanol twice, and dry at 60°C for 12 h to obtain nano ceria particles;

[0073] 6. Disperse the nano ceria particles in 50 mL of water, and obtain a nano ceria dispersion through a filter, and the pH value is measured to be 3.10.

[0074] The nano ceria dispersion obtained in the example is subjected to XRD test and TEM test, and the test results are as follows:

[0075] The XRD is as shown in Figure 7 , and it can be seen that the nano ceria particles in the nano ceria dispersion obtained in the example are of fluorite structure and have good crystallinity; the TEM picture and the particle size distribution graph are as shown in Figure 8 , and it can be seen that the primary particle size of the nano ceria particles in the nano ceria dispersion obtained in the example is 2-8 nm.

[0076] 1. Measure 10.16 g of Ce (NO3)3 . 6H2O, and dissolve in 50 mL of methanol to obtain solution A; measure 8.76 mL of ammonia water and add to 21.4 mL of methanol to obtain solution B;

[0077] 2. Put a 250 mL three-necked flask in a constant temperature water bath at 65°C, pour solution B into the three-necked flask, and start a digital electric stirrer, and adjust the rotating speed to be above 500 rpm to keep the stirring intensity; then pour solution A into the three-necked flask, and stir for 5 min until the reaction solution becomes purple;

[0078] 3. Measure 5 mL of hydrogen peroxide solution in 5 mL of methanol to obtain solution C;

[0079] 4. Add 12 mL of dilute nitric acid to adjust the pH value to 5.53, and slowly add solution C for oxidation reaction until the reaction solution becomes yellow. Stop stirring and cool down to obtain a mixture with a pH value of 3.79;

[0080] 5. Centrifuge the mixture at 5000 r / min for 5 min. Wash the yellow precipitate with anhydrous ethanol twice, and dry at 60°C for 12 h to obtain nano ceria particles;

[0081] 6. Disperse the nano ceria particles in 50 mL of water to obtain a yellow and clear nano ceria dispersion with a pH value of 2.82 by filtration.

[0082] The nano ceria particles and the nano ceria dispersion obtained in this example are subjected to XRD test, and the nano ceria dispersion is subjected to TEM test. The test results are as follows:

[0083] The XRD is as shown in Figure 9 , which shows that the nano ceria particles in the nano ceria particles and the nano ceria dispersion obtained in this example are of fluorite structure with good crystallinity. The TEM picture and the particle size distribution graph are as shown in Figure 10 , which shows that the primary particle size of the nano ceria particles in the nano ceria dispersion obtained in this example is 2-8 nm.

[0084] Preparation method of nano ceria particles and obtained nano ceria dispersion

[0085] 1. Weigh 5.08 g of Ce (NO3) 3 . 6H2O, and dissolve in 50 mL of methanol to obtain solution A. Measure 4.1 mL of ammonia water and add to 20 mL of methanol to obtain solution B.

[0086] 2. Place a 250 mL three-necked flask in a constant temperature water bath at 65°C. Pour solution B into the three-necked flask, and turn on the digital electric stirrer to adjust the rotation speed to more than 500 rpm to maintain the stirring intensity. Then pour solution A into the three-necked flask, and stir for 5 min until the obtained reaction solution becomes purple.

[0087] 3. Measure 1 mL of hydrogen peroxide solution and dissolve in 9 mL of methanol to obtain solution C.

[0088] 4. Add 5 mL of dilute nitric acid to adjust the pH value to 5.09, and slowly add solution C for oxidation reaction until the reaction solution becomes yellow. Stop stirring and cool down to obtain a mixture with a pH value of 3.89.

[0089] 5. The mixture was centrifuged at 5000 r / min for 5 min, and the yellow precipitate was washed twice with anhydrous ethanol by centrifugation and dried at 60°C for 12 h to obtain the nano ceria particles;

[0090] 6. The nano ceria particles were dispersed in 50 mL of water, and a nano ceria dispersion was obtained by filtration. The pH value was 2.73.

[0091] The nano ceria dispersion obtained in this example was subjected to XRD test, DLS particle size distribution test and TGA test. The test results showed that:

[0092] The XRD, as shown in Figure 11 , showed that the nano ceria particles in the nano ceria dispersion obtained in this example were of fluorite structure and had good crystallinity; the DLS particle size distribution graph, as shown in Figure 12 , showed that the average particle size of the nano ceria particles in the nano ceria dispersion obtained in this example was 19 nm, and the PDI was 0.399; and the TGA graph, as shown in Figure 13 , showed that the purity of the nano ceria particles in the nano ceria dispersion obtained in this example was 91.4%.

[0093] Example 6: Preparation method of nano ceria particles and obtained nano ceria dispersion

[0094] 1. 5.08 g of Ce(NO3)3 . 6H2O was weighed and dissolved in 100 mL of methanol to obtain solution A; 4.1 mL of ammonia water was measured and added to 40 mL of methanol to obtain solution B;

[0095] 2. A 250 mL three-necked flask was placed in a constant temperature water bath at 65°C, solution B was poured into the three-necked flask, and a digital electric stirrer was turned on to adjust the rotation speed to above 500 rpm to maintain the stirring intensity; then solution A was poured into the three-necked flask, and stirring reaction was carried out for 5 min until the reaction liquid became purple;

[0096] 3. 1 mL of hydrogen peroxide was measured and dissolved in 19 mL of methanol to obtain solution C;

[0097] 4. 1.3 mL of concentrated hydrochloric acid was added to the reaction liquid to control the pH value to 3.59, and solution C was slowly added dropwise for oxidation reaction until the reaction liquid became yellow, the stirring was stopped, and the temperature was lowered by standing to obtain a mixture with a pH value of 3.33;

[0098] 5. The mixture was centrifuged at 5000 r / min for 5 min to obtain a yellow precipitate, which was washed twice with anhydrous ethanol by centrifugation and dried at 60°C for 12 h to obtain nano ceria particles;

[0099] 6. The nano cerium oxide particles were dispersed in 50 mL of water, and a nano cerium oxide dispersion was obtained by filtering. The pH value of the nano cerium oxide dispersion was 2.61.

[0100] The nano cerium oxide dispersion obtained in this example was subjected to XRD testing and FT-IR testing, and the testing results are as follows:

[0101] As shown in the XRD spectrum in Figure 14 , it can be seen that the nano cerium oxide particles in the nano cerium oxide dispersion obtained in this example have a fluorite structure and good crystallinity; as shown in the FT-IR spectrum in Figure 14 , it can be seen that the surface of the nano cerium oxide particles in the nano cerium oxide dispersion obtained in this example is not modified.

[0102] Comparative Example 1

[0103] 1. 5.08 g of Ce(N03)3·6H20 was weighed and dissolved in 50 mL of methanol to obtain solution A; 4.1 mL of ammonia water was measured and added to 20 mL of methanol to obtain solution B; . 6H2O, dissolved in 50 mL of methanol to obtain solution A; 4.1 mL of ammonia water was measured and added to 20 mL of methanol to obtain solution B;

[0104] 2. A 250 mL three-necked flask was placed in a constant-temperature water bath at 65°C, solution B was poured into the three-necked flask, and a digital electric stirrer was turned on, and the stirring speed was adjusted to be above 500 rpm to maintain the stirring intensity; then solution A was poured into the three-necked flask, and stirring reaction was performed for 5 min until the reaction liquid became purple;

[0105] 3. 1 mL of hydrogen peroxide solution was measured and dissolved in 9 mL of methanol to obtain solution C;

[0106] 4. Solution C was slowly added dropwise for oxidation reaction until the reaction liquid became yellow, stirring was stopped, and the mixture was cooled by standing to obtain a mixture, and the acid-base property of the mixture was in the neutral range;

[0107] 5. The mixture was centrifuged at 5000 r / min for 5 min, the yellow precipitate was washed twice with anhydrous ethanol by centrifugation, and then the wet solid was dispersed in 50 mL of water, and standing was performed. Precipitate appeared, and a nano cerium oxide dispersion could not be obtained, and the pH value was 5.81.

[0108] The product obtained in this comparative example was subjected to XRD testing. The testing results showed that the substance prepared in this example was cerium oxide, and the XRD spectrum thereof had a fluorite structure and good crystallinity.

[0109] Comparative Example 2

[0110] 1. 5.08 g of Ce(N03)3·6H20 was weighed and dissolved in 50 mL of methanol to obtain solution A; 4.1 mL of ammonia water was measured and added to 20 mL of methanol to obtain solution B; . 6H2O, dissolved in 50 mL of methanol to obtain solution A; 4.1 mL of ammonia water was measured and added to 20 mL of methanol to obtain solution B;

[0111] 2. Put a 250 mL three-necked flask in a constant temperature water bath at 65°C, pour solution B into the three-necked flask, and start a digital electric stirrer, and adjust the rotation speed to be higher than 500 rpm to keep the stirring intensity; then pour solution A into the three-necked flask, and stir the reaction for 5 min until the reaction solution becomes purple;

[0112] 3. Measure 1 mL of hydrogen peroxide solution in 9 mL of methanol to obtain solution C;

[0113] 4. Add 2 mL of ammonia water to adjust the pH value to 8.54, slowly drop solution C for oxidation reaction until the reaction solution becomes yellow, stop stirring, and stand for cooling to obtain a mixed solution, which is in the alkaline range;

[0114] 5. Centrifuge the mixed solution at 5000 r / min for 5 min, wash the yellow precipitate with anhydrous ethanol twice, then disperse the wet solid in 50 mL of water, stand for stratification, and cannot obtain a nano cerium oxide dispersion, and the measured pH value is 6.94.

[0115] The product obtained in the present comparative example is subjected to XRD test. The test result shows that the substance prepared in the present example is cerium oxide, which has a fluorite structure and good crystallinity.

[0116] Obviously, the above examples of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description, and it is impossible to enumerate all the embodiments here. Any obvious changes or variations derived from the technical solutions of the present application are still within the protection scope of the present application.

Claims

1. A method for preparing nano ceria particles, characterized in that, The preparation method comprises the following steps: Ce(NO3)3 . 6H2O is dissolved in methanol to obtain solution A, the mass fraction of Ce(NO3)3 . 6H2O in the solution A is 6%-20%. The ammonia water is measured and added into the methanol to obtain a solution B, the mass fraction of the ammonia water in the solution B is 11%-32%; the Ce(NO3)3 . The molar ratio of 6H2O to ammonia water is 1:4-1:5; The solution A and the solution B are mixed and stirred to react, the reaction is a water bath reaction, the temperature is 60-70 DEG C, until the reaction liquid obtained is purple; Hydrogen peroxide is weighed and dissolved in methanol to obtain solution C, the volume ratio of the hydrogen peroxide to the methanol is 1:1-1:19; The pH value of the reaction liquid is controlled to be in an acidic range, solution C is added to carry out an oxidation reaction, until the reaction liquid is yellow, a mixed liquid is obtained; the method for controlling the pH value of the reaction liquid to be in the acidic range is to increase the ammonia gas volatilization speed by blowing nitrogen, so that the pH value of the reaction liquid is reduced; or an acid is added to reduce the pH value of the reaction liquid; the acidic range is 1-6; the pH value range of the mixed liquid is 1-5; The mixed liquid is centrifuged, washed and dried, to obtain nano cerium oxide particles; The primary particle size of the nano cerium oxide particles is within 2-8 nm.

2. The production method according to claim 1, characterized by, The Ce(NO3)3 . The molar ratio of 6H2O to ammonia is 1:4.

7.

3. The preparation method according to claim 1, characterized in that, The temperature of the water bath reaction is 65 DEG C.

4. The method of claim 1, wherein, The volume ratio of the hydrogen peroxide to the methanol is 1:

9.

5. The preparation method according to claim 1, characterized in that, The acidic range is 1.89-5.

53.

6. The method of claim 1, wherein, The pH value range of the mixed liquid is 1.76-4.33.

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