Vehicle Emission Solutions for China 6b and Euro 7 2020-01-0654
Combinations of CC1 TWC and CC2 coated gasoline particulate filters (cGPF) were aged by 4-mode and fuel cut aging to simulate 200K kilometers of in-use aging in China and Europe, respectively. Separate combinations of catalysts were then evaluated on two low emission engines using the WLTC driving cycle. Catalyst volume and PGM mass were varied in the CC1. OSC/washcoat amounts were varied at constant PGM loading in the GPF. For the Chinese application, after the four-mode aging, it was found that the CC1 TWC catalyst volume should be greater than 1.0 L. High levels of OSC were needed in the GPF to meet CO and NOx emission targets. For the European application, after fuel cut aging, Euro 6d emissions were met with any combination of TWC and GPF catalysts. If the gaseous regulations for Euro 7 are similar to China 6b, the CC1 TWC catalyst should also be great than 1.0 L in order to meet CO and NOx emissions. Over all, results imply that CC1 TWC design is most critical for gaseous emissions. More washcoat (i.e., bigger volume) in the CC1 is more effective for emission reduction than increased PGM. GPFs in the CC2 position may need high OSC/washcoat levels to achieve the CO and NOx emissions regulations for China 6b and Euro 7. The PN measurements for all GPFs were well within current regulations.