Abstract: A three-way catalyst article with improved ammonia emission control, and its use in an exhaust system for gasoline engines, is disclosed. The catalyst article for treating exhaust gas from a gasoline engine comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the inlet end, wherein the first catalytic region comprises a first zeolite; and a second catalytic region beginning at the outlet end, wherein the second catalytic region comprises a second platinum group metal (PGM) component, a second oxygen storage capacity (OSC) material, and a second inorganic oxide; wherein the second PGM component is selected from the group consisting of palladium, platinum, rhodium and a combination thereof.

Abstract: A catalyst article for treating exhaust gas from a gasoline engine comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the inlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first PGM component and a first inorganic oxide; a second catalytic region beginning at the outlet end, wherein the second catalytic region comprises a second PGM component, a second oxygen storage capacity (OSC) material, and a second inorganic oxide; wherein the first catalytic region is substantially free of ceria; and wherein the first PGM component is palladium (Pd), platinum (Pt) or a combination thereof.