Cost Effective Catalyst Solutions with Application of Low Mass Substrate to Meet China 6b Regulation Requirement

With upcoming China 6b emission regulation set for full implementation in July 2023, significant efforts are being made within China OEMs to meet the stringent gaseous emission requirements, which reduce gaseous emission limits by 29 to 50% from China 6a for NOx, THC, and CO over the worldwide harmonized light-duty test cycle (WLTC). With current engine and aftertreatment technology, cold-start emissions generated in the first 200 seconds of the WLTC typically makes up most of the total tailpipe emissions result, thus the reduction of cold-start emissions becomes vital to meet regulation requirements. Besides further improvement on engine technology with optimized calibration, a common method to improve cold-start performance is to add more platinum group metals (PGM) into three-way catalyst (TWC). An alternative approach to improve cold-start performance involves using a low mass substrate to enable faster heat up of the TWC. To evaluate this alternative approach, a TWC system with the low mass substrate was prepared and tested in direct comparison to the standard, high mass substrate over WLTC on chassis dyno. The results showed that the low mass substrate technology (Corning® FLORA® Substrates) 800/3.0 can achieve similar emission performance with about 10-25% less PGM in comparison to the standard substrate 750/2. The low mass substrate offered a significant reduction in time to light-off, enabling reduction of cold-start emissions. Additionally, the selected cost-effective solution was tested under a surrogate real driving emission (RDE) cycle, RTS95, in which the results showed it has the potential to meet China’s 6b RDE requirement.