Diesel particulate filter

摘要

A method of making a filter for filtering particulate matter from exhaust gas emitted from a lean-burn internal combustion engine, which filter comprising a porous substrate having inlet surfaces and outlet surfaces, wherein the inlet surfaces are separated from the outlet surfaces by a porous structure containing pores of a first mean pore size, wherein the inlet surfaces comprise a bridge network comprising interconnected particles of refractory material over the pores of the porous structure, which method comprising the step of contacting inlet surfaces of the filter substrate with an aerosol comprising refractory material in dry powder form. The invention also relates to a filter obtainable by such method.

主权项

1. A filter for filtering particulate matter from a lean-burn exhaust gas comprising:
(a) a porous substrate having an inlet surface and an outlet surface, wherein the inlet surface and the outlet surface are separated by a porous structure; and (b) a catalytic filter cake in the form of a bridge network on the inlet surface, said bridge network comprising interconnected inorganic particles selected from the group consisting of silicate zeolite, aluminosilicate zeolite, metal-substituted aluminosilicate zeolite, non-zeolitic molecular sieve, and metal oxide, provided that said metal oxide particles have an average size of greater than 0.2 μm and less than 5 μm, where the interconnected inorganic particles are dry aerosol deposited, the particles form a bridge over the pores.