A Study of Emission Durability and Ash Accumulation of “Advanced Three-Way Catalyst Integrated on Gasoline Particulate Filter” for BS6 (Stage2) Applications

India BS6 Stage2 (2023) regulations demands all Gasoline direct injection (GDI) vehicles to meet particulate number emissions (PN) below 6x10+11# per km. Gasoline particulate filters (GPF) are a proven technology and enable high PN filtration efficiencies throughout the entire vehicle lifetime. One challenge for GPF applications could be the changing emission performance characteristics as a function of mileage due to collected ash and/or soot deposits with implications on back pressure losses and well due to aging of active catalytic components like PGM and Washcoat. The main objective of this technical contribution is to study the above-mentioned challenges while applying Indian driving conditions and typical Indian climate and other ambient conditions. The substrate technology selected for this study is a high porosity GPF designed to enable the integration of a Three-Way functionality into the GPF, commonly described as coated GPF. In this study, the entire Three-Way Catalyst (TWC) functionality was integrated into a single component GPF system, a very package-attractive system approach. The objective of the described testing program is to evaluate the robustness of the GPF and applied catalyst technology over 160 000km under the mentioned conditions. The vehicle emissions were regularly evaluated in both: MIDC and WLTC. Many performance relevant parameters were collected during mileage accumulation; results of engine oil consumption, engine oil analysis, fuel consumption as well as permanent data recording via OBD and GPS. The GPF characteristics including soot load, ash load and pressure drop were evaluated at pre-defined check points by additional laboratory tests. The benefits of the tested system architecture which are: lower system volume, acceptable back pressure, high PN filtration efficiency, high conversion efficiency of gaseous emissions (CO, HC, NOX), excellent robustness, effective soot regeneration could be demonstrated and validated over a significantly high mileage.