초록 ▼

The invention is a method for preconditioning a palladium containing automotive catalyst by subjecting the catalyst to oxidation by means of an oxidizing gas containing at least 0.85% oxygen at a temperature of at least 450.degree. C. preferably for at least 15 seconds. This oxidation can be carried

The invention is a method for preconditioning a palladium containing automotive catalyst by subjecting the catalyst to oxidation by means of an oxidizing gas containing at least 0.85% oxygen at a temperature of at least 450.degree. C. preferably for at least 15 seconds. This oxidation can be carried out before or after engine shutdown. The catalyst is placed in the exhaust system in a location whereby the catalyst attains this temperature during steady state warm-up operation of the engine.

대표청구항 ▼

[ I claim:] [1.] A method for lowering the light-off temperature of a highly loaded palladium-containing three-way automotive vehicle catalyst during cold-starting of the vehicle engine, which method comprises the steps of:providing said palladium-containing catalyst comprising at least 100 g pallad

[ I claim:] [1.] A method for lowering the light-off temperature of a highly loaded palladium-containing three-way automotive vehicle catalyst during cold-starting of the vehicle engine, which method comprises the steps of:providing said palladium-containing catalyst comprising at least 100 g palladium/ft.sup.3 catalyst support material as the only catalyst in the exhaust system of an automotive vehicle at a location where the steady state warmed up operating temperatures of said system are at least 450.degree. C., andsubjecting said catalyst, after shutdown of said engine, to a flow of an oxidizing gas containing at least 0.85 volume % oxygen for a selected period of time while said catalyst is at an elevated temperature of at least 450.degree. C. in order to oxidize said catalyst,whereby the light-off temperature of the palladium-containing catalyst is lowered.