Thermal Ageing Induced Effects on Pd/LaFeO3 for NOx Reduction by Hydrocarbons: Influence of the Preparation Method

Abstract

The influence of the support synthesis for the preparation of supported Pd/LaFeO 3 perovskite based catalysts and the nature of the palladium precursor on the catalytic performances in the selective reduction of NO to N 2 by hydrocarbons have been investigated. According to the preparation method, subsequent surface and bulk characterisation revealed significant changes in the degree of dispersion and the chemical environment of oxidic palladium species depending on the extent of interaction with the support. Pd nitrate precursor leads to the stabilisation of the Pd surface concentration. The metal support interactions thus obtained strongly enhance the catalytic performances, particularly the resistance to thermal ageing whereas sol-gel synthesis produces the higher support activity.

First-principles investigation on the segregation of Pd at LaFe1-xPd x O3-y surfaces

“…Moreover, we further demonstrated that Pd has the strongest tendency to segregate at FeO 2 -terminated surfaces containing V O s, in comparison with three other surfaces, i.e., LaO-terminated surfaces with and without V O s and the perfect FeO 2 -terminated surfaces. Additionally, Lee et al [ 21 ] calculated a surface phase diagram of the LFO (010) surface and argued that the LaO-terminated surface could be predicted to be stable at lower temperature (773 K), which was in agreement with the previous experimental results measured by X-ray photoelectron spectra [ 22 , 23 ]. In contrast, the FeO 2 -terminated surface became dominant at high temperatures (>1,500 K).…”