Catalyst design for heavy-duty diesel combustion engines

摘要

Disclosed are washcoats, coated substrates formed from such washcoats, and catalytic converters for use in diesel applications, such as heavy duty diesel applications. Methods of preparing the coated substrates are also disclosed.

主权项

1. A coated substrate comprising:
a) a substrate; b) a first washcoat layer on the substrate comprising zeolites; c) a second washcoat layer on the substrate comprising a first catalytically active material comprising platinum and palladium, wherein the first catalytically active material comprises first composite nanoparticles embedded within porous micron-sized carrier particles; wherein the first composite nanoparticles comprises a first support nanoparticle and a first catalytic nanoparticle, wherein the first catalytic nanoparticle comprises a platinum-palladium alloy; and d) a third washcoat layer on the substrate comprising a second catalytically active material comprising platinum and palladium; wherein the second catalytically active material comprises second composite nanoparticles embedded within porous micron-sized carrier particles; wherein the second composite nanoparticles comprises a second support nanoparticle and a second catalytic nanoparticle, wherein the second catalytic nanoparticle comprises a platinum-palladium alloy; wherein the second washcoat layer is deposited on the first washcoat layer, and the third washcoat layer is deposited on the second washcoat layer.