Role of ceria in the improvement of SO2 resistance of LaxCe1 − xFeO3 catalysts for catalytic reduction of NO with CO

• LaFeO3 perovskite oxide has been proved as an excellent catalyst in the reaction between NO and CO.
• LaFeO3 catalyst is very sensitive to the addition of SO2 in CO + NO system.
• The addition of Ce to LaFeO3 catalyst enhances its SO2 resistance.

Perovskite-type catalysts with LaFeO3 and substituted LaxCe1 − xFeO3 compositions were prepared by sol–gel method. These catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), CO temperature-programmed reduction (CO-TPR), and SO2 temperature-programmed desorption (SO2-TPD). Catalytic reaction for NO reduction with CO in the presence of SO2 has been investigated in this study. LaFeO3 exhibited an excellent catalytic activity without SO2, but decreased sharply when SO2 gas was added to the CO + NO reaction system. In order to inhibit the effect of SO2, substitution of Ce in the structure of LaFeO3 perovskite has been investigated. It was found that La0.6Ce0.4FeO3 showed the maximum SO2 resistance among a series of LaxCe1 − xFeO3 composite oxides.

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