Effects of high octane additivated gasoline fuel on Three Way Catalysts performance under an accelerated catalyst ageing procedure

The adoption of high octane rating fuels in Gasoline Direct Injection (GDI) engines helps to improve fuel economy and thus reduce CO₂ emission. However, there is scarce literature regarding the impact of additives used in high octane rating fuels on the performance and durability of the exhaust after treatment components. This work investigates the effects of using an aniline (aromatic amine) octane enhancer added to a commercial gasoline fuel on the activity of a commercial Three Way Catalytic Converter (TWC) coupled to a GDI engine. TWC’s capability in abating gaseous and particle emissions is studied for both the additivated and the baseline fuel during and after a fuel-induced accelerated catalyst ageing procedure. The accelerated catalyst ageing procedure is developed aiming to identify the impact of the engine fuel on the catalyst poisoning, while limiting catalyst thermal deactivation.

CO and NO conversion efficiencies in the TWC were close to 100% under the steady-state and transient stoichiometric engine operation for both fuels during and after the catalyst ageing procedure. There was a minor decrease (generally < 10%) in the catalytic conversion efficiency of total HC for the additivated fuel, but not being significant to reflect any TWC chemical deactivation. The aniline type octane enhancer additive did not produce any detrimental effect on the TWC efficiency/performance. This investigation demonstrates that fuels being designed to promote a more efficient GDI engine operation can also enable the reduction of vehicle tailpipe CO2 and pollutant emissions through synergies with the TWC for cleaner road vehicles.