Patent ID: 7678347
Filing Date: 2010-03-16
Classification: B01D,B01J,F01N,Y02A,Y02T

Abstract:
1. An automobile exhaust gas treatment catalyst having increased resistance to poisoning from oil- and/or fuel-derived additives, comprising: a substrate having an upstream edge in initial contact with exhaust gas; optionally, a base coat coating said substrate, said base coat being devoid of precious metal or containing a low level of precious metal; a precious metal-containing first catalytic layer placed on said base coat or said substrate, said first catalytic layer having a higher level of precious metal than said base coat; at least one precious metal-containing further catalytic layer placed on said first layer, the at least one further catalytic layer containing a higher concentration of precious metal than the first catalytic layer; wherein only said at least one further catalytic layer contains a non-precious metal-containing poison capture zone, wherein said poison capture zone comprises an uncoated portion upstream of said at least one further catalytic layer, and said poison capture zone comprising a length of from about 0.5-5 cm from said upstream edge.