Three-way conversion catalyst composition comprising platinum-rhodium bimetallic components

A catalyst composition comprising:

• a) platinum;
• b) rhodium;
• and
• c) a ceria-alumina composite, a zirconia composite or a mixture thereof,
• wherein platinum is supported on the ceria-alumina composite, zirconia composite or mixture thereof in an amount of 0.1 to 10 wt. %, based on the total weight of the ceria-alumina composite and/or zirconia composite,
• wherein rhodium is supported on the ceria-alumina composite, zirconia composite or mixture thereof in an amount of 0.1 to 10 wt. %, based on the total weight of the ceria-alumina composite and/or zirconia composite,
• wherein CeO2 in the ceria-alumina composite is 1.0 to 50 wt. %, based on the total weight of the ceria-alumina composite,
• wherein the amount of ZrO2 in the zirconia composite is 50 to 99 wt. %, based on the total weight of the zirconia composite.