Evaluation of Different Resistively Heated Catalyst Technologies

Fresh, resistively heated quick light-off catalysts were obtained from two industry sources and evaluated on a neat methanol-fueled vehicle. Catalyst air assist was used, and a larger volume main converter was also added behind each quick light-off catalyst. The objective of this testing was to reduce excess unburned fuel, carbon monoxide, and formaldehyde emissions over the cold start portion (Bag 1) of the Federal test procedure (FTP) at 24°C.

The lowest emission rates occurred with the use of a two-catalyst system (resistively heated/air assisted quick light-off catalyst and conventional main catalyst). Bag 1 conversion efficiencies in excess of 99 percent from no-catalyst levels were noted for unburned fuel and formaldehyde, and 96 percent for carbon monoxide with these two catalyst systems.