A catalyst for the treatment of exhaust gases from an internal combustion engine comprises a support including a porous layer which latter includes at least one inorganic refractory oxide and an active phase containing at least cerium, iron and platinum, characterized in that said porous layer comprises at least the following percentages by weight0.3% to 4.4% of cerium;0.1% to 3.5% of iron; and0.0003% to 0.04% of platinum; andthe complement to 100% being constituted by at least one inorganic refractory oxide.The catalyst can be used in the treatment of exhaust gases from compression ignition engines, in particular from commercial vehicles with an unladen weight of 3.5 metric tons or more.