Catalytic Oxidation of Styrene over Ce-Substituted La_1–<i>x</i>Ce_<i>x</i>MnO₃ Catalysts

Abstract

A series of Ce-substituted La1–xCexMnO3 (x = 0–0.5) catalysts were prepared by a sol–gel method and displayed good crystalline perovskite structure. The activities of styrene catalytic oxidation were investigated at a low temperature range. La1–xCexMnO3 catalysts improved the activity for styrene oxidation, and the complete removal was obtained below 370 °C. Among the Ce-doping catalysts, La0.9Ce0.1MnO3 displayed the highest activity. The structural property of the catalysts exhibited a strong impact on the catalytic activity. Ce4+ substitution caused the alteration of both the valence state of manganese ions and chemical state of oxygen species. The surface Mn4+/Mn3+ ratio was increased thanks to the Ce-doping, but the Oβ/Oα ratio decreased. The variation of elemental ratios on the surface facilitated the catalysts reducibility, which played a determining role on the catalyst activity. The increased activity was due to a collaborative influence of surface area, reducibility, and surface elemental ratios.