Design of Catalyzed Gasoline Particulate Filter (cGPF) and Investigation of Its Durability Performance Using Accelerated Engine Aging

Catalyzed gasoline particulate filters (cGPF) are one of the most effective emission control technologies for reducing gaseous and particulate emissions simultaneously. Successful adoption of this advanced technology relies on several important performance properties including low back pressure, high filtration efficiency and specially durability compliance. In this work using an underfloor cGPF, the backpressure control was achieved through optimizing catalyst coating technology and modifying the deposition profile of catalyst coating along GPF channels. Durability performance was demonstrated by using an accelerated engine aging method with selective blending of lubricating oils in fuel, which incorporates the aging mechanisms of thermal aging, ash loading, and soot accumulation/regeneration. The target durability demonstration represents 200,000 km real world operation. The durability performance was evaluated by a series of vehicle emission tests, and comparison with traditional thermal aging methods, such as GMAC-875°C. Additional characterization methods, such as Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy (SEM-EDS), X-Ray Fluorescence (XRF) and backpressure measurement were applied to investigate the ash deposition profile inside cGPF and interaction with cGPF, and the properties of ash obtained from two different lubricant formulations respectively. The results show that the three-stage aging protocol developed from this work can effectively demonstrate cGPF durability performance. At the end of durability testing, the aged cGPF can still meet China 6 emission regulation requirement.