Cataler Corporation

Ryo Tasaki

Ryota Onoe

Momoko Iwai

Yamato Matsushita

Takahiro Noguchi

Shunsuke Oishi

Masaya Ito

Koki Aono

An exhaust gas purifying catalyst includes a base material and a catalyst layer. A first catalyst region including the catalyst layer formed therein is provided on an entry side surface of a partition wall of the base material. A second catalyst region including the catalyst layer formed on a wall surface of a pore is provided in a prescribed region from an exit side surface of the partition wall toward an entry side cell. A catalyst unformed region in which a catalyst layer is substantially not formed is provided between the first and second catalyst regions in the thickness direction Y of the partition wall. Thus, it is possible to prevent the deposition of PMs in the second catalyst region including the catalyst layer formed in the pore, and to establish the compatibility between the noxious gas purifying performance and the pressure loss suppressing performance at a high level.

Exhaust gas purification catalyst

A particulate filter includes a base material having a wall-flow structure including porous partition walls partitioning inlet and outlet cells, and wash-coating layers held inside partition walls. The wash-coating layers include inlet layers each formed from vicinity of an end portion at exhaust gas inflow side to have predetermined length and thickness and outlet layers each formed from vicinity of end portion at exhaust gas outflow side to have a predetermined length and thickness. The inlet and the outlet layers partially overlap with each other. Inlet layers of particulate filter contain substantially no noble metal catalyst, and outlet layers contain noble metal catalyst. Accordingly, PM collection performance can be easily enhanced in inlet region, and high gas distributability (pressure loss suppression performance) can be maintained in outlet region. Accordingly, it is possible to provide particulate filter capable of achieving high levels of PM collection performance and pressure loss suppression performance.

Particulate filter

An exhaust gas purification catalyst provides excellent removal performance of methane, which is chemically stable. Exhaust gas purification catalyst includes a substrate that divides cells through which an exhaust gas flows and a catalyst layer that is provided on a surface of the substrate. The catalyst layer includes a palladium layer containing palladium that extends from a first end part which is an end part on the side into which an exhaust gas in the cells flows to a second end part which is an end part on the side from which an exhaust gas flows out, a platinum layer containing platinum that extends from the second end part to the first end part, and a rhodium layer containing rhodium that is laminated with both the palladium layer and the platinum layer.

The technology disclosed herein provides a particulate filter that can appropriately avoid PM from passing toward the outlet cell and can exhibit an excellent PM capturing performance. The particulate filterdisclosed herein includes: an outercoat layerprovided on an inlet surfaceof a partitionof a base material. The outercoat layerat least includes: a lower layerprovided on the inlet surfaceof the partition; and an upper layerprovided to cover the lower layer. The mean particle diameter of granules contained in the upper layeris higher than the mean particle diameter of granules contained in the lower layer. The mean particle diameter of the granules in the lower layeris from 0.4 μm to 2.0 μm inclusive, and the mean particle diameter of the granules in the upper layeris from 2.0 μm to 7.0 μm inclusive. With such a configuration, PM can be captured in an inlet cell, thereby suitably avoiding PM from passing toward an outlet celland exhibiting an excellent PM capturing performance.

A particulate filter disclosed herein includes a wall-flow structure substrateand a wash coat layerheld inside a partitionof the substrate. The wash coat layerincludes an inlet layerformed to have predetermined length Land thickness Tfrom near an end thereof on an exhaust gas inflow side X, and an outlet layerformed to have predetermined length Land thickness Tfrom near an end thereof on an exhaust gas outflow side X. The inlet layerand the outlet layerpartially overlap each other. In the particulate filter disclosed herein, the inlet layercontains a precious metal catalyst, while the outlet layercontains substantially no precious metal catalyst. The length Lof the inlet layer is 50% or more and 75% or less of a total length L of the partition. Thus, the particulate filter is capable of achieving both PM collection performance and pressure-drop reduction performance at high levels.

Provided is a particulate filter in which a PM collection rate is stably increased. The particulate filter according to the present invention includes a substratehaving a wall flow structure having a porous partition wallthat partitions an inlet cell and an outlet cell, and a wash coat layer held on surfaces of internal pores of the partition wall. In addition, average filling rates A, B, and C of the wash coat layer measured for each predetermined pore diameter range in the internal pores satisfy specific relationships. Further, the wash coat layer is formed in a region that occupies 50% or more of a thickness of the partition wall, and an amount of a noble metal catalyst carried by the wash coat layer is 0 g/L or more but 0.2 g/L or less.

Growing community of inventors

Shizuoka, Japan

Ryo Tasaki