Three-way catalyst used for automobile emission purification and preparation method thereof

Abstract

The invention relates to a three-way catalyst used for automobile emission purification and a preparation method thereof, and belongs to the field of atmospheric pollution regulation and environment-friendly catalytic materials. The catalyst uses a cordierite honeycomb ceramic as a carrier, a mixture coating of Gamma-Al2O3 and rare earth complex oxide (Ce-Zr-M-Ox) as a promoter, and transition metals of Co and Ni, and precious metals of Pd and Rh as catalytic activity components. According to the invention, through the adoption of a sol method, the pre-treated carrier is coated with the promoter coating, the carrier coated with the promoter coating is dipped into a precursor complex solution of catalytic activity components by using an equal-volume dipping method, and the catalyst is obtained through drying and roasting. The three-way catalyst has low precious metal content; the transition metals of Co and Ni have well concerted catalysis with the precious metals; higher three-way catalytic activities and excellent low temperature ignition performances are shown; carbon monoxide, nitrogen oxide, and hydrocarbon in automobile exhaust can be effectively removed; the preparation process of the catalyst is simple.

Description

technical field [0001] The invention relates to a three-way catalyst for purifying automobile tail gas and a preparation method thereof, belonging to the fields of air pollution control and environmental protection catalytic materials. Background technique [0002] After the car is started, due to incomplete combustion of fuel or high temperature, the exhaust gas contains a large amount of CO, HC, NO x And other substances that are very harmful to the human body, especially in large and medium-sized cities, these harmful substances are dispersed in the urban surface atmosphere, and it is difficult to effectively disperse, which makes the quality of the atmospheric environment worse and seriously endangers human health. Reduce carbon monoxide (CO) and nitrogen oxides (NO) in automobile exhaust x ) and hydrocarbons (HC) and other pollutants is the installation of off-board automotive exhaust catalytic converter, the most critical technology is the preparation of three-way cat...

AI Technical Summary

Problems solved by technology

[0003] At present, the commercial catalysts used in the domestic and foreign markets for the purification of automobile exhaust are all precious metal types (such as US5157007, UK1499051, etc.), which are relatively expensive. Exhaust gas purification catalysts, and in the world, the reserves of precious metals such as Pt, Pd, Rh are very small and are mainly distributed in a few countries such as South Africa and Russia; in addition, a variety of non-precious metals and rare earth composite oxide catalysts (such as CN85102282A, CN86103200A, etc.), the price is low, but due to the high ignition temperature, NO x Due to low conversion rate and other reasons, the market application is limited

Images