Effect of Sulfur on the Performance of Three-Way Catalysts

Sulfur content is one of the fuel properties to be monitored. Sulfur dioxide, the major product derived from organic sulfur compounds in the exhaust gas emissions, is a poison to the three-way catalysts (TWC). A gas mixture was applied to simulate the exhaust gases used in the TWC aging procedure tests. Two types of the TWC, REX-ⅡC and REX-ⅡD, were tested in this study. The performance of both TWC's before and after the 100-hour sulfur aging program was compared. It was concluded that the Pt component in the TWC was apt to be poisoned by sulfur much easily than Rh. The performance of the REX-ⅡD catalyst was generally better than that of the REX-ⅡC catalyst.

Sulfur content is one of the fuel properties to be monitored. Sulfur dioxide, the major product derived from organic sulfur compounds in the exhaust gas emissions, is a poison to the three-way catalysts (TWC). A gas mixture was applied to simulate the exhaust gases used in the TWC aging procedure tests. Two types of the TWC, REX-IIC and REX-IID, were tested in this study. The performance of both TWC's before and after the 100-hour sulfur aging program was compared. It was concluded that the Pt component in the TWC was apt to be poisoned by sulfur much easily than Rh. The performance of the REX-IID catalyst was generally better than that of the REX-IIC catalyst.