Preparation method for palladium-doped cerium-zirconium composite oxide

Abstract

The invention discloses a preparation method for a palladium-doped cerium-zirconium composite oxide. The preparation method includes the following steps: cerium acetate and zirconium acetate are dissolved in deionized water, and a first mixed solution is obtained after uniform mixing; OP-10, P123 and n-butyl alcohol are respectively dripped into a solvent (methylbenzene), the mass ratio of the OP-10, the P123 and the n-butyl alcohol is 5-6 to 2-3 to 10-15, and a second mixed solution II is obtained after uniform mixing; the first mixed solution and the second mixed solution are mixed and stirred at a high speed to obtain a mixed emulsion; 2 weight percent palladium acetate is dripped in the mixed emulsion, and the mixture is stirred uniformly; 20 weight percent ammonium hydroxide is prepared to serve as a precipitator; the mixed emulsion and the precipitator (the 20 weight percent ammonium hydroxide) are then mixed, the mixture is stirred at a high speed for 2 to 3 hours and then stands for 12 to 24 hours within a temperature range of 40 to 50 DEG C, and a dirty solution is obtained; the dirty solution goes through high-speed centrifugal separation and suction filtration, and obtained solid phase matters are dried within a temperature range of 100 to 120 DEG C and calcined within a temperature range of 400 to 500 DEG C to obtain the palladium-doped nanometer cerium-zirconium composite oxide. The palladium-doped cerium-zirconium composite oxide prepared through the method has the characteristics of small particle diameter (the diameter can reach the nanometer level), large specific surface area and oxygen storage capacity, high oxygen storage and discharge rates, and high sintering resistance.

Description

technical field [0001] The invention relates to a preparation method of a palladium-doped cerium-zirconium composite oxide. Background technique [0002] Energy and the environment are the most important issues involved in the sustainable development of human society. With the depletion of petroleum resources and the increasing environmental pollution, my country's standards and requirements for automobile exhaust emissions are getting higher and higher. Three-way catalysts for automobile exhaust It is a multi-component composite catalyst, which mainly eliminates carbon monoxide, nitrogen oxides and hydrocarbons at the same time. [0003] CeO 2 The study of its related materials has received great attention, and relevant studies have shown that in CeO 2 ZrO 2 Forming a solid solution can greatly improve its oxygen storage and release performance and high temperature resistance. CeO 2 It is an excellent additive for oxidation-type catalysts with a fluorite structure. It h...

AI Technical Summary

Problems solved by technology

[0005] The cerium-zirconium solid solution prepared by the commonly used technology and process has the disadvantages of low oxygen storage capacity, slow oxygen storage and release rate, small specific surface area, and poor sintering resistance.

Therefore, the development of high-performance cerium-zirconium solid solution is the research focus of automobile exhaust treatment. According to literature and patent reports, the commonly used methods for preparing cerium-zirconium solid solution include coprecipitation method, sol-gel method, hydrothermal synthesis method, etc., but these The cerium-zirconium solid solutions prepared in the prior art generally have disadvantages such as relatively large particle size, small specific surface area, and low oxygen storage capacity.