Sulfur Storage and Release from Automotive Catalysts

An H₂S odor problem has appeared for certain vehicles fitted with modern three-way catalysts. A sulfur storage/H₂s release mechanism is proposed as a source of the odor problem. The effects of various operating parameters on the release of H₂S are presented. Two methods of modifying three-way catalysts to minimize H₂S release while maintaining good catalyst performance and high temperature durability are demonstrated.