Evaluation of Metallic and Electrically Heated Metallic Catalysts on a Gasoline Fueled Vehicle

Prototype metallic and electrically heated metallic catalysts (EHC) are being evaluated on a gasoline fueled vehicle. The vehicle used for this evaluation is a 5.0L Mustang equipped with an emissions control system which includes mass air, and sequential electronic fuel injection (SEFI). FTP tests are performed to evaluate non-heated metallic and electrically heated metallic catalysts in both production and close-coupled configurations. The objective of the evaluation is to determine light-off characteristics of both the non-heated metallic and the EHCs and their effect on cold-start emissions (Bag 1). FTP results are compared to those obtained from conventional ceramic catalysts in the same configurations. Initial data show some emissions benefits for the prototype EHC converter during the first 60 seconds or so of the FTP. From 60 seconds on in the FTP cycle, the ceramic catalyst was slightly more efficient, leading to overall FTP emissions about the same for the two systems. In the case of the closecoupled configuration, consisting of a small mini metallic light-off catalyst in addition to a production ceramic TWC and COC, overall FTP emissions (Bags 1,2,3) show significant improvement in both HC and CO emissions but little or no NO_x emission improvement. The results also indicate that the overall benefit from an electrically-heated catalyst depend strongly on the particular vehicle and emissions system under investigation.