Comparative activity and hydrothermal stability of FeOx- and CeO2-doped Pt-based catalysts for eliminating diesel emissions

Abstract

Diesel emissions (CO/C3H6/ NO) were eliminated on FeOx-doped and CeO2-doped Pt-based catalysts respectively to compare reaction mechanism and performance features. FeOx-doped catalyst has a higher platinum dispersion, a higher platinum valance state retarding CO adsorption and a higher oxygen mobility. Both of the higher dispersion and the oxygen mobility have a positive role in low-temperature catalytic oxidation performance, lower by 26 °C for CO light-off temperature and 12 °C for C3H6 light-off temperature respectively than CeO2-doped catalyst. On FeOx-doped catalyst, the lesser surficial active oxygen species form the byproduct Fe(NO), resulting in an reduction of 10% NO maximum conversion. Besides, hydrothermal aged FeOx-doped catalyst with reduction treatment show a relatively lower light-off temperature and a higher NO max conversion. The difference in reaction characterization enlighten that the composition of oxidation catalyst would focus on the specific performance for the practical configuration in aftertreatment system for the better diesel emissions prevention.