Cerium oxide and zirconium oxide based composite rare earth oxide with favorable ageing resistance and high reduction activity and preparation method of cerium oxide and zirconium oxide based composite rare earth oxide

Abstract

Provided is a method for preparing cerium oxide and zirconium oxide based composite rare earth oxide. The method comprises: (1) preparing a zircon salt solution; (2) prepare an activating agent solution by mixing urea and sulfuric acid or sulfate; (3) heating the zircon salt solution at a room temperature, dropwise adding the activating agent solution slowly, controlling the temperature rise speed to make the temperature raised to 60 degrees centigrade after the addition of the activating agent solution is finished, continuing to raising the temperature to 90 to 95 degrees centigrade, and keeping the temperature for 20-100min to form a basic zirconium sulfate composite salt precursor solution; (4) preparing soluble cerate and rare earth metal salt, adding the soluble cerate and the rare earth metal salt into the basic zirconium sulfate composite salt precursor solution, and performing precipitation by using a soluble hydroxide or ammonia solution; and (5) filtering and cleaning precipitates, and then, calcining the precipitates. Also provided is a cerium oxide and zirconium oxide based composite rare earth oxide prepared by using the method.

Description

technical field

[0001] The invention relates to a ceria-zirconia-based composite rare-earth oxide and a preparation method thereof, in particular to a ceria-zirconia-based composite rare-earth oxide with good aging resistance and high reduction activity and a preparation method thereof. Background technique

[0002] Because the tail gas emissions of automobiles, motorcycles and tractors, especially motor vehicles such as automobiles, have become the main source of air pollution in large and medium-sized cities in the world, and the most effective measure to control motor vehicle exhaust emissions is to install off-board vehicle exhaust purifiers. As the activated carbon layer of the carrier of the automobile exhaust purifier, the cerium-composite material has become an indispensable material for the automobile catalyst. The cerium-composite material has good oxygen storage capacity and high-temperature hydrothermal stability, which can effectively widen the air-fuel ratio wi...

Examples

Embodiment 1

[0027] A method for preparing a ceria-zirconia-based composite rare earth oxide, the method comprising the following steps:

[0028] (1) Preparation of soluble zirconium salt: Weigh a certain mass of zirconium oxychloride, dissolve zirconium oxychloride in water, and prepare a 25wt% zirconium oxychloride solution;

[0029] (2) Prepare activator solution: mix urea and sulfuric acid to prepare 10wt% activator solution, wherein the mass ratio of urea to zirconium oxychloride in step (1) is 1:99, and the sulfate radical and step (1) The mass ratio of zirconium oxychloride is 3:5;

[0030](3) Heat the zirconium oxychloride solution in step (1) at room temperature, and slowly add the activator solution in step (2) dropwise, and control the heating rate so that the temperature rises to 60°C when the activator solution is added dropwise , and then continue to heat up, from 60°C to 90°C within 30 minutes, and keep warm for 100 minutes to form a basic zirconium sulfate compound salt pr...

Embodiment 2

[0035] A method for preparing a ceria-zirconia-based composite rare earth oxide, the method comprising the following steps:

[0036] (1) Preparation of soluble zirconium salt: Weigh a certain mass of zirconyl nitrate, dissolve zirconyl nitrate in water, and prepare a 20wt% zirconyl nitrate solution;

[0037] (2) Prepare activator solution: mix urea and sodium sulfate to prepare 15wt% activator solution, wherein the mass ratio of urea to zirconyl nitrate in step (1) is 2:98, and the sulfate radical and step (1) The mass ratio of zirconyl nitrate in the medium is 1:3;

[0038] (3) Heat the zirconyl nitrate solution in step (1) at room temperature, and slowly add the activator solution in step (2) dropwise, and control the heating rate so that the temperature rises to 60°C when the activator solution is added dropwise. Then continue to heat up, from 60°C to 92°C within 30 minutes, and keep it warm for 60 minutes to form a basic zirconium sulfate compound salt precursor solution;...

Embodiment 3

[0043] A method for preparing a ceria-zirconia-based composite rare earth oxide, the method comprising the following steps:

[0044] (1) Preparation of soluble zirconium salt: Weigh a certain quality of zirconium oxalate, dissolve zirconium oxalate in water, and prepare a 25wt% zirconium oxalate solution;

[0045] (2) Prepare activator solution: mix urea and potassium sulfate to prepare a 10wt% activator solution, wherein the mass ratio of urea to zirconium oxalate in step (1) is 1.5:98.5, and the sulfate radical and step ( 1) The mass ratio of zirconium oxalate in the medium is 2:5;

[0046] (3) Heat the zirconium oxalate solution in step (1) at room temperature, and slowly add the activator solution in step (2) dropwise, and control the heating rate so that the temperature rises to 60°C when the activator solution is added dropwise, and then Continue to heat up, from 60°C to 95°C within 30 minutes, and keep it for 20 minutes to form a basic zirconium sulfate compound salt p...

technical field

[0001] The invention relates to a ceria-zirconia-based composite rare-earth oxide and a preparation method thereof, in particular to a ceria-zirconia-based composite rare-earth oxide with good aging resistance and high reduction activity and a preparation method thereof. Background technique

[0002] Because the tail gas emissions of automobiles, motorcycles and tractors, especially motor vehicles such as automobiles, have become the main source of air pollution in large and medium-sized cities in the world, and the most effective measure to control motor vehicle exhaust emissions is to install off-board vehicle exhaust purifiers. As the activated carbon layer of the carrier of the automobile exhaust purifier, the cerium-composite material has become an indispensable material for the automobile catalyst. The cerium-composite material has good oxygen storage capacity and high-temperature hydrothermal stability, which can effectively widen the air-fuel ratio wi...

Examples

Embodiment 1

[0027] A method for preparing a ceria-zirconia-based composite rare earth oxide, the method comprising the following steps:

[0028] (1) Preparation of soluble zirconium salt: Weigh a certain mass of zirconium oxychloride, dissolve zirconium oxychloride in water, and prepare a 25wt% zirconium oxychloride solution;

[0029] (2) Prepare activator solution: mix urea and sulfuric acid to prepare 10wt% activator solution, wherein the mass ratio of urea to zirconium oxychloride in step (1) is 1:99, and the sulfate radical and step (1) The mass ratio of zirconium oxychloride is 3:5;

[0030](3) Heat the zirconium oxychloride solution in step (1) at room temperature, and slowly add the activator solution in step (2) dropwise, and control the heating rate so that the temperature rises to 60°C when the activator solution is added dropwise , and then continue to heat up, from 60°C to 90°C within 30 minutes, and keep warm for 100 minutes to form a basic zirconium sulfate compound salt pr...

Embodiment 2

[0035] A method for preparing a ceria-zirconia-based composite rare earth oxide, the method comprising the following steps:

[0036] (1) Preparation of soluble zirconium salt: Weigh a certain mass of zirconyl nitrate, dissolve zirconyl nitrate in water, and prepare a 20wt% zirconyl nitrate solution;

[0037] (2) Prepare activator solution: mix urea and sodium sulfate to prepare 15wt% activator solution, wherein the mass ratio of urea to zirconyl nitrate in step (1) is 2:98, and the sulfate radical and step (1) The mass ratio of zirconyl nitrate in the medium is 1:3;

[0038] (3) Heat the zirconyl nitrate solution in step (1) at room temperature, and slowly add the activator solution in step (2) dropwise, and control the heating rate so that the temperature rises to 60°C when the activator solution is added dropwise. Then continue to heat up, from 60°C to 92°C within 30 minutes, and keep it warm for 60 minutes to form a basic zirconium sulfate compound salt precursor solution;...

Embodiment 3

[0043] A method for preparing a ceria-zirconia-based composite rare earth oxide, the method comprising the following steps:

[0044] (1) Preparation of soluble zirconium salt: Weigh a certain quality of zirconium oxalate, dissolve zirconium oxalate in water, and prepare a 25wt% zirconium oxalate solution;

[0045] (2) Prepare activator solution: mix urea and potassium sulfate to prepare a 10wt% activator solution, wherein the mass ratio of urea to zirconium oxalate in step (1) is 1.5:98.5, and the sulfate radical and step ( 1) The mass ratio of zirconium oxalate in the medium is 2:5;

[0046] (3) Heat the zirconium oxalate solution in step (1) at room temperature, and slowly add the activator solution in step (2) dropwise, and control the heating rate so that the temperature rises to 60°C when the activator solution is added dropwise, and then Continue to heat up, from 60°C to 95°C within 30 minutes, and keep it for 20 minutes to form a basic zirconium sulfate compound salt p...