Exhaust gas treatment catalyst

Abstract

Provided are an exhaust treatment catalyst and an exhaust article containing the catalyst. The catalyst comprises: (a) a carrier; (b) a first layer deposited on the carrier, said first layer comprising substantially only at least one refractive metal oxide; (c) a second layer deposited on the first layer, said second layer comprising substantially only at least one oxygen storage component and at least one binder therefor; and (d) a third layer deposited on the second layer, said third layer comprising at least one layer of one or more platinum group metal components supported on a refractory metal oxide support. Optionally, a fourth layer is deposited on the third layer wherein the fourth layer comprises one or more platinum group metal components supported on a refractory metal oxide support. As a further option, an overcoat layer may be deposited on the third or fourth layer wherein the overcoat layer comprises a catalyst poison sorbent. Also provided are methods for preparing the catalyst and methods for monitoring the exhaust storage capacity of an exhaust article containing the catalyst.

Dependencies are inferred from the claim text.