Catalyst with highly annealed Pd layer

A method for producing a multilayer catalyst for exhaust gas after-treatment of combustion exhaust gases, comprising the following steps:

• a) providing a substrate having a surface which contacts the gases to be cleaned;
• b) preparing a first catalytically effective composition by placing a first oxygen storage material comprising CexCryOz, wherein z=2, x>0.5, y<0.5 and x+y=1 in water, adding a solution comprising a palladium salt to obtain a first slurry, and placing aluminum oxide into the first slurry,
• c) applying the first catalytically effective composition comprising the first oxygen storage material and the palladium salt onto the surface of the substrate to produce a first layer (A);
• d) annealing the first layer (A) at a first temperature T1 in a range of 550 to 700° C. for a period of time t1 of five minutes or more;
• e) subsequently annealing the first layer (A) at a second temperature T2 in a range of 700 to 1200° C. which is 100 to 400° C. higher than T1;
• f) preparing a second catalytically effective composition by placing a second oxygen storage material in water, adding a solution comprising at least one of a platinum salt and a rhodium salt to obtain a second slurry, and placing aluminum oxide into the second slurry;
• g) applying the second catalytically effective composition comprising at least one of a platinum salt and a rhodium salt to produce a second layer (B), wherein the second layer (B) fully or partially covers the annealed layer (A);
• and
• h) annealing the second layer (B) at a third temperature T3 in a range of 400 to 700° C.