A selective catalytic reduction filter (SCRF) including a wall-flow substrate having inlet channels and outlet channels is provided. A first selective catalytic reduction (SCR) catalyst zone is present in the inlet channels, and a second SCR catalyst zone is present in the outlet channels. The first SCR catalyst zone includes an iron-exchanged zeolite catalyst, and the second SCR catalyst zone includes a copper-exchanged zeolite catalyst. Exhaust gas treatment systems including the SCRF and methods of reducing production of nitrous oxide (N.sub.2O) during selective catalytic reduction of an exhaust gas stream using the SCRF are also provided herein.

An oxidation catalyst is described for treating an exhaust gas produced by a diesel engine comprising a catalytic region and a substrate, wherein the catalytic region comprises a catalytic material comprising: bismuth (Bi), antimony (Sb) or an oxide thereof; a platinum group metal (PGM) selected from the group consisting of (i) platinum (Pt), (ii) palladium (Pd) and (iii) platinum (Pt) and palladium (Pd); and a support material, which is a refractory oxide; wherein the platinum group metal (PGM) is supported on the support material; and wherein the bismuth (Bi), antimony (Sb) or an oxide thereof is supported on the support material and/or the refractory oxide comprises the bismuth, antimony or an oxide thereof.

A method for the removal of nitrogen oxides from exhaust, flue or off gas by selective catalytic reduction in presence of ammonia as a reductant, comprising the steps of contacting the exhaust gas together with the ammonia or a precursor thereof with an SCR catalyst comprising a Fe-AEI zeolite material essentially free of alkali metal ions (Alk), having the following molar compositions:
SiO.sub.2:oAl.sub.2O.sub.3:pFe:qAlk
wherein o is in the range from 0.001 to 0.2;
wherein p is in the range from 0.001 to 0.2;
wherein Alk is one or more of alkali metal ions and wherein q is below 0.02.

An oxidation catalyst device for exhaust gas purification, having a first catalyst coating layer on the exhaust gas flow's upstream side, second catalyst coating layer of an upper layer on exhaust gas flow's downstream side, and third catalyst coating layer of a lower layer on exhaust gas flow's downstream side, on a substrate, wherein the weight ratio of platinum to palladium in the first catalyst coating layer is 0.75 to 4.50, weight ratio of platinum to palladium in second catalyst coating layer is greater than 4.50 to 25.0, weight ratio of platinum to palladium in third catalyst coating layer is 0.12 or less, the length of first catalyst coating layer is 8% to 55% of the substrate's length, length of second catalyst coating layer is 45% to 95% of the substrate's length, and length of third catalyst coating layer is 45% to 95% of the substrate's length.

An oxidation catalyst for treating an exhaust gas from a diesel engine, which oxidation catalyst comprises: a first washcoat region comprising platinum (Pt), manganese (Mn) and a first support material; a second washcoat region comprising a platinum group metal (PGM) and a second support material; and a substrate having an inlet end and an outlet end; wherein the second washcoat region is arranged to contact the exhaust gas at the outlet end of the substrate and after contact of the exhaust gas with the first washcoat region.

A selective catalytic reduction filter (SCRF) including a wall-flow substrate having inlet channels and outlet channels is provided. A first selective catalytic reduction (SCR) catalyst zone is present in the inlet channels, and a second SCR catalyst zone is present in the outlet channels. The first SCR catalyst zone includes an iron-exchanged zeolite catalyst, and the second SCR catalyst zone includes a copper-exchanged zeolite catalyst. Exhaust gas treatment systems including the SCRF and methods of reducing production of nitrous oxide (N.sub.2O) during selective catalytic reduction of an exhaust gas stream using the SCRF are also provided herein.

The present invention relates to a SCR catalyst comprising a carrier substrate of the length L, which is a flow-through substrate, and a coating A which comprises a small pore zeolite, copper and palladium.

An oxidation catalyst is described for treating an exhaust gas produced by a diesel engine comprising a catalytic region and a substrate, wherein the catalytic region comprises a catalytic material comprising: bismuth (Bi), antimony (Sb) or an oxide thereof; a platinum group metal (PGM) selected from the group consisting of (i) platinum (Pt), (ii) palladium (Pd) and (iii) platinum (Pt) and palladium (Pd); and a support material, which is a refractory oxide; wherein the platinum group metal (PGM) is supported on the support material; and wherein the bismuth (Bi), antimony (Sb) or an oxide thereof is supported on the support material and/or the refractory oxide comprises the bismuth, antimony or an oxide thereof.

An oxidation catalyst is described for treating an exhaust gas produced by a diesel engine comprising a catalytic region and a substrate, wherein the catalytic region comprises a catalytic material comprising: iron (Fe) or an oxide thereof; a platinum group metal (PGM) selected from the group consisting of (i) platinum (Pt), (ii) palladium (Pd) and (iii) platinum (Pt) and palladium (Pd); and a support material, which is a refractory oxide comprising alumina; wherein the platinum group metal (PGM) and the iron (Fe) or an oxide thereof is each supported on the support material.

A method for producing a ceramic honeycomb filter having a ceramic honeycomb structure having plugs in predetermined cells: comprising using an apparatus having a reservoir having an inlet for a plugging material slurry and an upper opening, a porous plate with pluralities of openings covering the upper opening of the reservoir, and a holding member fixed to an upper end of the reservoir; keeping a lower surface of the sealing film attached to a lower end surface of the ceramic honeycomb structure apart from an upper surface of the porous plate by a distance D of more than 0 mm and 2.0 mm or less; supplying a predetermined volume of the plugging material slurry into the reservoir to introduce it into the predetermined cells of the ceramic honeycomb structure; rotating the ceramic honeycomb structure after sealing of the ceramic honeycomb structure is released; and lifting the ceramic honeycomb structure after the rotation starts.