US Patent 9545602 Catalytic article for treating exhaust gas

Provided is a catalytic article comprising (a) a flow through honeycomb substrate having channel walls; (b) a first NH3-SCR catalyst composition coated on and/or within the channel walls in a first zone; and (c) a second NH3-SCR catalyst composition coated on and/or within the channel walls in a second zone, provided that the first zone is upstream of the second zone and the first and second zones are adjacent or at least partially overlap; and wherein the first NH3-SCR catalyst comprises a first copper loaded molecular sieve having a copper to aluminum atomic ratio of about 0.1 to 0.375 and the second NH3-SCR catalyst comprises a second copper loaded molecular sieve having a copper-to-aluminum atomic ratio of about 0.3 to about 0.6.