Layered catalyst composite
AssigneeEngelhard Corporation
InventorYuejin Li
Life of this patent
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Abstract
A layered catalyst composite for controlling vehicular exhaust emissions is disclosed. The composite comprises a substrate such as cordierite, at least one bottom layer deposited on the substrate containing a precious metal component such as platinum and at least one NOx storage component present in the amount of about 0.3 to about 1.5 g/in3, and at least one top layer deposited on the bottom layer containing a precious metal component such as platinum and at least one NOx storage component present in the amount of about 0.0 to less than about 0.3 g/in3.
Claims35
A layered catalyst composite for controlling vehicular exhaust emissions comprising:
- (a) a substrate;
- (b) at least one bottom layer having a bottom surface and a top surface wherein the bottom surface is adjacent to, and in contact with, the substrate, said bottom layer comprising a support upon which is deposited:
- (i) a precious metal component which consists of a platinum metal component and (ii) at least one NOx storage component present in the amount of about 0.3 to about 1.5 g/in3;
- and
- (c) at least one top layer having a bottom surface and a top surface wherein the bottom surface is adjacent to, and in contact with, the top surface of the bottom layer, said top layer comprising a support upon which is deposited (i) at least one precious metal which consists of a component selected from platinum and rhodium metal components, and (ii) at least one NOx storage component present in the amount of 0.0 to less than about 0.3 g/in3.
Dependencies are inferred from the claim text.