Catalyst coating for gasoline particulate filter carrier and preparation method of catalyst coating

Abstract

The invention relates to a catalyst coating for a gasoline particulate filter carrier. The catalyst coating is smeared inside a GPF (gasoline particulate filter) carrier channel and is prepared by mixing at least three kinds of grout A-C, specifically, the grout A comprises modified alumina and a noble metal active component, and the content of the noble metal active component is 0.01-1.5%; the grout B comprises a composite oxide Ce1 and a noble metal active component, and the content of the noble metal active component is 0.01-6.0%; and the grout C comprises a composite oxide Ce2 and a noblemetal active component, and the content of the noble metal active component is 0.01-6.0%. The at least three kinds of grout with noble metal active components of different contents are prepared, the noble metal active components in the catalyst which is prepared by mixing the grout finally can be sufficiently dispersed, the prepared catalyst can be smeared inside the GPF carrier channel at a single time, purification of the GPF to CO, HC, NOX and particulates can be improved while the back pressure of the GPF is slightly affected, and exhaust emission, particularly PM (particulate matter) andPN (particulate number) emission, can meet requirements of the national VI emission standards.

Description

technical field [0001] The invention belongs to the technical field of gasoline engine tail gas purification, and in particular relates to a catalyst coating for a gasoline engine particle filter carrier and a preparation method thereof. Background technique [0002] According to the regulations of the sixth stage emission standard of light vehicle pollutants in my country, starting from July 1, 2020, the allowable emission value of particle number PN in gasoline vehicle exhaust is 6.0*10 11 each / Km. For naturally aspirated engines, the particulate matter in the exhaust gas is less, which can meet the requirements of emission standards. For turbocharged engines, the particulate matter (PM, Particulate Matter) and particle number (PN, Particle Numbers) in the exhaust gas may be difficult to meet the requirements of emission standards. For in-cylinder direct injection engines, the particulate matter and the number of particles in the exhaust far exceed the requirements of em...

AI Technical Summary

Problems solved by technology

GPF is a semi-open structure. After use, the back pressure of the exhaust system will increase significantly, which will affect fuel consumption and pollutant emission control. After coating with catalyst coating, although the catalytic conversion efficiency of exhaust gas can be improved, the coating The coating has an impact on the increase of back pressure; secondly, the semi-open structure of GPF determines the difficulty of catalyst coating coating, which requires specific coating processes and methods to achieve

[0004] The document with the application number CN201711057455.7 discloses a GPF quaternary catalyst, including a GPF carrier and a catalyst coating coated on the wall surface of the inlet port of the GPF carrier, including: catalytic metal oxide 0~13%, Activated alumina 30~60%, rare earth-transition metal composite oxide 30~60%, active component (including the first noble metal Pd or Pt and Rh oxide) 0~3%, the rest is binder; Efficient purification of CO, HC, NO while not blocking the pores of GPF ceramics and reducing catalyst back pressure x , particles, to achieve four-way catalysis, the preparation process of this method is complicated, and it is easy to cause the consumption and uneven distribution of the noble metal active components that play the main catalytic role in the preparation process, resulting in the problem of poor catalytic effect

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