Gasoline particle filter (GPF) development includes optimization of multiple, competing targets: low backpressure, high clean filtration, acceptable strength, high oxygen storage capacity, small size, and low cost. A three-way catalyst + GPF system needs to meet targets for hydrocarbons, carbon monoxide, and nitrogen oxides in addition to particle mass and/or particle number. GPFs behave differently than diesel particle filters (DPFs) in terms of regeneration and ash loading behavior due to vastly different operating conditions. In a relatively clean exhaust condition on GDI relative to diesel, an empty GPF can have filtration efficiencies on the order of 60%. This was improved to 80-90% with a small amount of soot and/or ash on the filter walls, or higher catalyst washcoat loading. In the course of this work, models were developed to predict backpressure, filtration, and chemical performance.

No abstract

No abstract

No abstract

No abstract