Evaluation of the sulfur tolerance of ``sulfur tolerant`` automotive catalysts from three commercial catalyst suppliers

Sulfur has previously been shown to reduce the performance of automotive catalytic converters and to cause significant increases in vehicle emissions. This research program was undertaken to determine the extent to which sulfur-tolerant automotive catalysts might exist within the supplier community. Meetings were held with the four largest global manufacturers of automotive catalysts, and sulfur-tolerant catalysts were requested from each. The request was for a sample of their most sulfur-tolerant technology as well as a catalyst with the same noble metal content, but without the sulfur-tolerant technology. Three of the four companies supplied samples, one elected not to participate. A catalyst used on a vehicle that has been certified to the California LEV emission standard was also included in the test matrix.