Advanced Low Mass Ceramic Substrate for improved Cold Start Performance Targeting PROCONVE L8 Light-Duty Emissions Regulations 2022-36-0027

Brazilian Emissions Regulations are getting tighter in the coming years. With PROCONVE L7 in Jan-2023 and PROCONVE L8 in 2025, regulated emissions limits will significantly decrease, such as, the NMOG + NOx standard from 130 mg/km (PL6) to 50 mg/km (PL8). This challenge will necessitate better aftertreatment performance, with expected increases the catalytic converter PGM content, and consequently higher system cost.

It is understood that approximately 75% of an engine’s gaseous pollutants occur during the first few seconds after a cold start, thus it is crucial to promote the emissions conversion performance during that period. One approach is to decrease the heat capacity of the catalytic system, which can be done by utilizing cordierite substrates with thinner walls or an increased material porosity. CORNING has developed an innovative technology to substantially raise the porosity of conventional ultra-thin wall substrates from 35% to 55%, while maintaining their strength. This advanced low mass design allows for a reduction of the substrate volumetric heat capacity, enabling a faster thermal response for improved catalytic function and lower tailpipe emissions.

With an aim to understand the performance of the advanced low mass substrate technology within Brazil’s traditional ethanol-fuel environment, an emissions test program was performed using a modern 1.0L turbo-charged E100 engine on a transient dynamometer. The aftertreatment system consisted of 2 catalytic converters; a 1.26L converter in the closed-coupled position, and a 1.0L converter in the underfloor position. The focus of the study was to evaluate the substrate impact in the close-coupled catalyst, while the maintaining the underfloor catalyst. The baseline reference was a standard 750/2 substrate with a conventional TWC formulation in the close-coupled position. To explore the emission and cost reduction potential, samples of the low mass, high porosity substrates were coated and tested with the same TWC formulation, as well as, with reduced precious metal content. Prior to testing, all samples were oven-aged at 900°C to represent an end-of-life condition. Emission testing procedures followed the USEPA FTP75 protocols. Results from this study confirmed that the advanced low mass substrate can significantly reduce emissions (THC emissions by roughly 13%) or allow for lower PGM loadings without emissions penalty.