Method for preparing nano-cerium oxide and zirconia solid solution

Abstract

The invention discloses a method for preparing nano-cerium oxide and zirconia solid solutions, which belongs to the field of inorganic catalytic materials. The method comprises: dissolving cerium-containing ionic compound accounting for 10 to 90 percent of the weight of the raw materials and zirconium-containing ionic compound accounting for 10 to 90 percent of the weight of the raw materials in deionized water respectively according to a formulation of raw materials of nano-cerium oxide and zirconia solid solutions, and preparing the two into solutions with the concentration between 1 and 3 M; mixing the two solutions, adding alkaline substances, regulating pH between 7 and 10 to generate precipitate, aging the precipitate through heat treatment, performing washing and centrifugal filtration to obtain a filter cake; dissolving the obtained filter cake in nitric acid, adding surfactant to obtain milky white colloid; and performing calcination to prepare composite oxide of nano-cerium oxide / zirconia. Nano-sized particles prepared by the method improve the microstructure of cerium / zirconium solid solutions, and the prepared nano-composite oxide solid solutions have better thermal stability and larger specific surface area.

Description

Technical field:

[0001] The invention relates to a preparation method of nano cerium oxide and zirconia solid solution. This kind of composite oxide solid solution can be used in automobile exhaust gas purification catalysts and other catalytic materials. technical background:

[0002] my country's rare earth reserves account for nearly 70% of the world's total reserves, and both its rare earth reserves and output rank first in the world. In 1995, the amount of rare earths was second only to the United States, ranking second in the world; since 2000, my country's rare earth consumption has surpassed that of the United States, ranking first in the world. In 2003, my country's rare earth consumption accounted for 35% of the world's total consumption. In the United States, auto catalysts are the largest user of rare earth raw materials, while the proportion of rare earths used in auto catalysts in my country is relatively small. In 1996, the amount of rare earths used in auto...

Examples

Embodiment 1

[0033] Using the sol-gel method: the source of cerium in the raw material is cerium nitrate Ce(NO 3 ) 3 ·6H 2 O, the zirconium source is ZrO(NO 3 ) 2 2H 2 O. The surfactant is sodium dodecylbenzenesulfonate. Add zirconyl nitrate solution with a concentration of 0.1 mol / L to the cerium nitrate solution at a concentration of 0.1 mol / L, and the molar ratio of cerium nitrate to zirconyl nitrate is 1:3. Aqueous ammonia at a concentration of 1 mol / L was added to the mixture of the two solutions to adjust the pH value to 9, and then the solution was adjusted to 120° C. and maintained for 6 hours. After filtering and washing for many times, pure hydroxide precipitates are obtained, and the precipitates are subjected to heat treatment and aging. After the precipitation, the precipitation particles with complete crystal form are obtained through heat treatment, and the precipitation is more complete and stable. The temperature of the treatment is 120° C., and the time is 6 hours....

Embodiment 2

[0037] Using sol-gel method: cerium source is cerium nitrate Ce(NO 3 ) 3·6H 2 O, the zirconium source is ZrO(NO 3 ) 2 2H 2 O, the surfactant is sodium dodecylbenzenesulfonate, 0.1 mol / L zirconyl nitrate solution is added to the 1 mol / L cerium nitrate solution, and the molar ratio of cerium nitrate to zirconyl nitrate is 1:1. Add 0.1 mol / L ammonia water to the mixture of the two solutions to adjust the pH value to 10, then adjust the solution to 120° C. and keep it for 6 hours. After filtering and washing for many times, pure hydroxide precipitates were obtained, and the precipitates were subjected to heat treatment at a temperature of 100° C. for 0.5 hours. Then the precipitate is dissolved in 0.1mol / L nitric acid, the sum of the concentrations of the cerium-zirconium composite oxide is adjusted to 35g / L, and the surfactant sodium dodecylbenzenesulfonate is added in an amount of cerium-zirconium composite oxide 0.5% by weight, and transferred to a three-necked flask at 1...

Embodiment 3

[0041] Using sol-gel method: cerium source is cerium nitrate Ce(NO 3 ) 3 ·6H 2 O, the zirconium source is ZrO(NO 3 ) 2 2H 2 O, the surfactant is sodium dodecylbenzenesulfonate, add 1 mol / L zirconyl nitrate solution to the 0.1 mol / L cerium nitrate solution, and the molar ratio of cerium nitrate to zirconyl nitrate is 3:1. Add 1 mol / L ammonia water to the mixture of the two solutions to adjust the pH value to 9, then adjust the solution to 120° C. and maintain it for 6 hours. After filtering and washing for many times, pure hydroxide precipitates were obtained, and the precipitates were heat-treated at a temperature of 300° C. for 24 hours. Then the precipitate is dissolved in 1mol / L nitric acid, the sum of the concentration of the cerium-zirconium composite oxide is adjusted to 35g / L, and the surfactant sodium dodecylbenzenesulfonate is added in an amount equal to the weight of the cerium-zirconium composite oxide 0.5% of the solution, and transferred to a three-neck flas...

Technical field:

[0001] The invention relates to a preparation method of nano cerium oxide and zirconia solid solution. This kind of composite oxide solid solution can be used in automobile exhaust gas purification catalysts and other catalytic materials. technical background:

[0002] my country's rare earth reserves account for nearly 70% of the world's total reserves, and both its rare earth reserves and output rank first in the world. In 1995, the amount of rare earths was second only to the United States, ranking second in the world; since 2000, my country's rare earth consumption has surpassed that of the United States, ranking first in the world. In 2003, my country's rare earth consumption accounted for 35% of the world's total consumption. In the United States, auto catalysts are the largest user of rare earth raw materials, while the proportion of rare earths used in auto catalysts in my country is relatively small. In 1996, the amount of rare earths used in auto...

Examples

Embodiment 1

[0033] Using the sol-gel method: the source of cerium in the raw material is cerium nitrate Ce(NO 3 ) 3 ·6H 2 O, the zirconium source is ZrO(NO 3 ) 2 2H 2 O. The surfactant is sodium dodecylbenzenesulfonate. Add zirconyl nitrate solution with a concentration of 0.1 mol / L to the cerium nitrate solution at a concentration of 0.1 mol / L, and the molar ratio of cerium nitrate to zirconyl nitrate is 1:3. Aqueous ammonia at a concentration of 1 mol / L was added to the mixture of the two solutions to adjust the pH value to 9, and then the solution was adjusted to 120° C. and maintained for 6 hours. After filtering and washing for many times, pure hydroxide precipitates are obtained, and the precipitates are subjected to heat treatment and aging. After the precipitation, the precipitation particles with complete crystal form are obtained through heat treatment, and the precipitation is more complete and stable. The temperature of the treatment is 120° C., and the time is 6 hours....

Embodiment 2

[0037] Using sol-gel method: cerium source is cerium nitrate Ce(NO 3 ) 3·6H 2 O, the zirconium source is ZrO(NO 3 ) 2 2H 2 O, the surfactant is sodium dodecylbenzenesulfonate, 0.1 mol / L zirconyl nitrate solution is added to the 1 mol / L cerium nitrate solution, and the molar ratio of cerium nitrate to zirconyl nitrate is 1:1. Add 0.1 mol / L ammonia water to the mixture of the two solutions to adjust the pH value to 10, then adjust the solution to 120° C. and keep it for 6 hours. After filtering and washing for many times, pure hydroxide precipitates were obtained, and the precipitates were subjected to heat treatment at a temperature of 100° C. for 0.5 hours. Then the precipitate is dissolved in 0.1mol / L nitric acid, the sum of the concentrations of the cerium-zirconium composite oxide is adjusted to 35g / L, and the surfactant sodium dodecylbenzenesulfonate is added in an amount of cerium-zirconium composite oxide 0.5% by weight, and transferred to a three-necked flask at 1...

Embodiment 3

[0041] Using sol-gel method: cerium source is cerium nitrate Ce(NO 3 ) 3 ·6H 2 O, the zirconium source is ZrO(NO 3 ) 2 2H 2 O, the surfactant is sodium dodecylbenzenesulfonate, add 1 mol / L zirconyl nitrate solution to the 0.1 mol / L cerium nitrate solution, and the molar ratio of cerium nitrate to zirconyl nitrate is 3:1. Add 1 mol / L ammonia water to the mixture of the two solutions to adjust the pH value to 9, then adjust the solution to 120° C. and maintain it for 6 hours. After filtering and washing for many times, pure hydroxide precipitates were obtained, and the precipitates were heat-treated at a temperature of 300° C. for 24 hours. Then the precipitate is dissolved in 1mol / L nitric acid, the sum of the concentration of the cerium-zirconium composite oxide is adjusted to 35g / L, and the surfactant sodium dodecylbenzenesulfonate is added in an amount equal to the weight of the cerium-zirconium composite oxide 0.5% of the solution, and transferred to a three-neck flas...

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