Catalytic oxidation of dichloromethane over Pt/CeO2–Al2O3 catalysts

A series of CeO2–Al2O3 catalysts with different CeO2 contents were prepared by a co-precipitation method, and supported Pt/CeO2–Al2O3 catalysts were also prepared by an impregnation method. These catalysts were tested for catalytic oxidation of dichloromethane (CH2Cl2). It was found that these catalysts were active for the reaction, with a 100% conversion of CH2Cl2 obtained at 410 °C over a catalyst with 15% of CeO2. Various characterization results such as ammonia temperature programmed desorption, hydrogen temperature programmed reduction suggested that the catalytic behaviors were synergistically influenced by surface acidity and redox property of the catalysts. An optimal combination of surface acidity and redox property in the catalyst resulted in a high activity. Moreover, the addition of Pt could further enhance the activity, due to the promotion of surface acidity by the introduction of chlorine species in the catalyst during the preparation using H2PtCl6 as the precursor and reducibility of the catalyst probably via the formation of Ce–Pt–O solid solution.

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► CeO2–Al2O3 catalysts are effective for catalytic oxidation of dichloromethane.
► The enhanced activity is due to synergy of surface acidity and redox property of the catalyst.
► Pt addition further promotes the reducibility of the catalyst and thus the activity.