Preparation method for diesel particulate filter with low back pressure and high soot filtration efficiency

Abstract

The invention discloses a preparation method for a diesel particulate filter with low back pressure and high soot filtration efficiency. A diesel particulate filter adopts a honeycomb ceramic wall flow carrier, and a carrier coating is a double layer coating structure; a bottom layer is formed by directly being coated on the carrier and includes high temperature and oxidation resistant ceramic powder particles, so that a porous ceramic film can be formed, wherein the porosity of the bottom layer is greater than that of a filtering wall of the honeycomb ceramic wall flow carrier; and a top layer is coated with a catalytic material which can catalyze and oxidize soot particles, and a formed catalytic layer can be directly in contact with the soot particles. Through the optimization of the porosity and pore sizes of the coating structure of the bottom layer, and the optimization of the catalytic material of the catalytic layer of the top layer and coating loading capacity, the filtering efficiency of the coating on the soot particles can be enhanced, DPF back pressure can be reduced, the surface deposition of the soot particles on the DPF filtering wall can be increased, the contact of the catalytic coating of the top layer with the soot particles can be further increased, and the Catalytic oxidation removal capabilities on the soot particles can be accelerated.

Description

technical field [0001] The invention belongs to the technical field of motor vehicle and ship engine tail gas treatment, and in particular relates to a preparation technology of a diesel particulate filter with good low back pressure and high soot filtering efficiency. Background technique [0002] Diesel engine has the obvious advantages of high thermal efficiency and good economy, but it is also accompanied by the emission of a large amount of soot particulate matter (Particulate Matter: PM) and NOx, which cause serious harm to the environment and human health. With stricter requirements, the removal of NOx and PM has become an inevitable trend, especially for the removal of PM, the use of wall-flow honeycomb ceramic particle filters (Diesel Particulate Filters: DPF for short) has also become an inevitable choice. [0003] In the post-treatment purification system, DPF, as the key unit to effectively remove PM, can capture PM very effectively, and its capture efficiency is...

AI Technical Summary

Problems solved by technology

The problem to be solved by the present invention is to provide a soot particle filter with a double-coating structure, which solves the problems of high back pressure and low filtration efficiency of the soot filter, and regulates the pores of the coating by optimizing the structure of the bottom coating efficiency and pore size distribution, and at the same time optimize the structure of the top coating to prepare a diesel particulate filter with low back pressure and high soot filtration efficiency, which will trap soot particles more effectively and remove them at the same time

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