Enhanced Soot Oxidation Performance of CeO2-Promoted La2O2SO4 Catalytic Oxygen Storage Materials for Gasoline Particulate Filters

This study investigates the synergistic promotional effects of CeO 2 and La 2 O 2 SO 4 as com- posite catalytic oxygen storage systems for soot oxidation in Gasoline Particulate Filters (GPF s ) across a broad operating temperature range. Two 5 wt.% CeO 2 promoted Lantha- num oxysulfate compounds were prepared by mechanical mixing of pure phases or by supporting CeO 2 via incipient wetness impregnation with a cerium nitrate precursor. The soot oxidation activity was evaluated using Thermogravimetric Analysis coupled with Mass Spectrometry (TG MS) under both anaerobic and lean O 2 (1 %vol .) environments, with the performance benchmarked against pure La or Pr oxysulfates and CeO 2 reference materials. Comprehensive characterization via XRD, SEM, N 2 physisorption, and H 2 TPR revealed that the observed synergistic effects transcend the simple additive properties of the individual components.