Automobile exhaust gas purifying catalyst preparation method

Abstract

The present invention discloses an automobile exhaust gas purifying catalyst preparation method, a noble metal, cerium and zirconium are prepared into a noble-metal-containing cerium-zirconium solid solution by a co-precipitation method, the method is simple in process and easy to control, and the noble-metal-containing cerium-zirconium solid solution obtained by the method has more micropores, high specific surface area and good oxygen storage and release capacity.

Description

technical field [0001] The invention relates to a preparation method of a catalyst for purifying automobile tail gas, in particular to a preparation method of a solid solution catalyst doped with elements cerium, zirconium and precious metal elements. Background technique [0002] With the increase of the number of motor vehicles, carbon monoxide, nitrogen oxides, and hydrocarbons emitted into the atmosphere by motor vehicles have brought great harm to the human environment. At present, the three-way catalyst mainly treats the exhaust gas that is fueled by the purification of gasoline. This three-way catalyst uses alumina with a high specific surface area and cerium-zirconium composite oxide with rich oxygen storage and release capabilities as the carrier, and its active component is noble metal. (Pt, Pd, Rh) and other metal elements, the powder material is prepared by making a cohesive slurry and coating it on a cordierite ceramic honeycomb carrier. [0003] For example, C...

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Problems solved by technology

However, multi-layer coating leads to the uncontrollable distribution position and state of most active components, and the active components inside the coating are not conducive to being fully utilized, and multi-layer coating prolongs the production cycle

[0005] In the existing catalyst coating preparation process, the main active component noble metal elements are loaded on the inside and surface of the carrier material. If the noble metal is attached to the surface of the carrier at a high temperature, it is very easy to sinter and agglomerate and deactivate; if the noble metal is loaded inside the carrier material , because there are few micropores inside the carrier material that can be used for gas diffusion, it is difficult for harmful gas to reach the precious metal inside the carrier material through the micropores.

Due to the lack of effective catalytic active sites and low utilization rate of the catalyst prepared by the existing preparation method, the tail gas treatment effect is not good