Laboratory-scale ageing and poisoning procedures were performed on selected diesel catalysts. The results showed that phosphorus
poisoning together with high temperature ageing has a strong effect on the catalytic activity and microstructure of platinum
containing catalysts. Phosphorus poisoning contaminated the catalysts resulting in phosphate formation, e.g. CePO
4 and AlPO
4. Poisoning and air ageing increased platinum particle-size and washcoat grain-size.
Keywords deactivation - diesel catalysts - phosphorus - poisoning - TEM