Advanced Platinum-Rhodium Exhaust Catalysts - An Economic Alternative To Palladium-Rhodium

Three-way catalysts based on the use of palladium have proved highly effective at meeting the most stringent emissions legislation around the world. This has led to a rapid increase in the amount of palladium used in autocatalyst applications which has contributed to an increase in the palladium price. This has prompted a renewed interest in the use of platinum in advanced three-way catalyst (TWC) formulations. This paper compares the performance of advanced platinum-rhodium and palladium-rhodium technology on an engine test-bed. This showed the new platinum-rhodium catalyst to have equal or better performance at similar precious metal cost. Tests on selected vehicles confirmed future emissions standards can be achieved using the platinum-based catalysts.