Patent ID: 7718143
Filing Date: 2010-05-18
Classification: B01D,F01N,Y02T

Abstract:
1. A filter catalyst for purifying exhaust gases having coarse PMs and fine PMs entrapped therein, comprising: a honeycomb filter having a porosity of 60% by volume; a catalytic layer formed on a surface of the cellular walls and an inner surface of the pores, and including a support powder composed of a porous oxide and a catalytic ingredient loaded on the support powder; and a fibrous layer formed on the outermost surface of the cellular walls of the inlet cells, and including entangled fibrous substances composed of a heat-resistant material, the fibrous layer having a second porosity different from the first porosity; wherein the second porosity is 30%-80% by volume obtained by using the fibrous substances having an aspect ratio of 1 to 60; wherein an oxidizing catalyst is loaded on the fibrous layer; wherein the fibrous layer is applied to the outermost surface of the cellular cells in a unitary areal weight of from 3 to 11 g/m wherein the honeycomb filter is arranged such that the exhaust gases flow in sequence through said inlet cells, said fibrous layer, said cellular walls, and said outlet cells; wherein said fibrous layers first filters the coarse PMs from the exhaust gas, and subsequently the cellular walls filter the fine PMs from the exhaust gas.