Deterioration of Three-Way Automotive Catalysts, Part II - Oxygen Storage Capacity at Exhaust Conditions 930944
Catalysts aged under different on-road conditions were analysed with respect to their conversion of CO and HC at step changes of the synthetic exhaust gas composition. Time resolved diode laser spectroscopy and fast response FID analysis were used to characterise the catalyst response to transient changes of CO and hydrocarbons in the exhaust gas. The oxygen storage capacity was monitored at various conditions; flow rate, catalyst temperature, previous exposure to oxidizing or reducing atmosphere and amplitude of the perturbation.
The technique appeared to provide a sensitive probe for analysis of the dynamic oxygen storage capacity of new and aged catalysts at exhaust like conditions. The results correlate well with the transient emission performance during vehicle tests.
Further, surface characterization using SEM/EDS and XPS techniques indicated that phosphate formation was the most probable cause of deactivation. A strong relationship between phosphate content and catalyst performance properties was found. The possible nature of this phosphorous deactivation function is discussed.
Citation: Smedler, G., Eriksson, S., Lindblad, M., Bernler, H. et al., "Deterioration of Three-Way Automotive Catalysts, Part II - Oxygen Storage Capacity at Exhaust Conditions," SAE Technical Paper 930944, 1993, https://doi.org/10.4271/930944. Download Citation
Gudmund Smedler, Sören Eriksson, Magnus Lindblad, Hans Bernler, Staffan Lundgren, Edward Jobson
Volvo Car Corp., Volvo Technological Development
International Congress & Exposition
Advanced Three-way Catalysts-PT-123, U.S. and European Automotive Emissions Technology-SP-0957, SAE 1993 Transactions: Journal of Fuels & Lubricants-V102-4