HC-Induced Deactivation in CO Conversion at Diesel Oxidation Catalysts

This paper examines the activity of a platinum catalyst for the oxidation of CO under conditions of temperature cycling. Each cycle consists of an ignition and extinction curve obtained with a linear temperature ramp. It is shown that the catalyst activity is higher for the first ignition cycle than for the subsequent ones regarding CO conversion. The activity for the extinction portion of each cycle is the same for all cycles. It is proposed that the loss of catalyst activity results from the deposition of hydrocarbon residues during the extinction part of the cycle. The catalyst activity can be completely restored by heating the catalyst to 350 °C in the presence of oxygen and nitrogen.