Preparation process of diesel DOC catalyst

Abstract

The invention discloses a preparation process of a diesel DOC catalyst. The preparation process includes the specific steps of: 1, mixing aluminum oxide powder, iron oxide powder, chromium oxide powder and ionized water according to certain proportion to prepare a slurry with a solid content of 42-50%, putting the slurry into a ball mill or sand mill for grinding, and taking out the slurry from agrinding tank; 2, slowly adding a noble metal salt solution dropwise into the slurry obtained in step 1 by a pipette for full wetting, performing stirring, and then conducting standing at 30-75DEG C for 2-5h to obtain a sample; and 3, drying the sample obtained in step 2 in a vacuum drying box at 90-110DEG C for 8-12h, and then performing calcination in a muffle furnace at 520-580DEG C for 3-6h. The preparation process of the diesel DOC catalyst provided by the invention effectively improves the durability of the catalyst, and at the same time improves the conversion rate of the catalyst coating on pollutants at high temperature.

Description

technical field [0001] The invention relates to the field of automobile tail gas treatment, in particular to a preparation process of a diesel engine DOC catalyst. Background technique [0002] In recent years, the development momentum of diesel vehicles is very rapid. Compared with gasoline vehicles, diesel vehicles have many advantages such as superior environmental performance, good power performance and less fuel consumption. Therefore, compared with gasoline vehicles, diesel vehicles have better economy, and are more and more concerned and favored by everyone. At the same time, diesel vehicle exhaust emission standards are becoming increasingly stringent, which also puts forward higher requirements for diesel vehicle exhaust after-treatment technology. Among them, the diesel vehicle oxidation catalyst (DOC,) is one of the important exhaust gas purification catalysts in the diesel vehicle exhaust gas treatment system. [0003] The use of DOC effectively removes CO, HC...

AI Technical Summary

Problems solved by technology

However, due to the fact that the quality of oil products in many areas of the country cannot meet the national standards, coupled with the harsh environment of the car and the bad driving habits of the car owner, the service life of the catalyst is greatly reduced, and the catalyst is seriously poisoned and invalid.

[0004] In addition, the current coating process of DOC catalyst is directly coating on the carrier, without pretreatment of the DOC carrier before coating, so that the adhesion with the carrier is not enough, resulting in the coating layer falling off during use, so that DOC catalyst failure