Double-layer three-way catalyst

A catalyst for reducing the harmful components in the exhaust gas of a combustion engine, in particular a predominantly stoichiometrically operated combustion engine, which comprises two layers arranged one above the other on an inert catalyst support, wherein

• a layer A contains at least palladium as a platinum group metal, aluminum oxide and a first cerium/zirconium/lanthanum/yttrium mixed oxide and
• a layer B applied to layer A contains at least rhodium as a platinum group metal, aluminum oxide and a second cerium/zirconium/lanthanum/yttrium mixed oxide,
• in both layers A and B, the lanthanum oxide content is between 1 wt. % and 5 wt. %, based on the cerium/zirconium/lanthanum/yttrium mixed oxide, and the yttrium oxide content is between 8 wt. % and 20 wt. %, based on the cerium/zirconium/lanthanum/yttrium mixed oxide,
• characterized in that
• layer A has a mass ratio of aluminum oxide to mixed oxide of at least 2.5:1 and at most 3.5:1.