CeO_(2)的形貌构筑及其对1,2-二氯乙烷氧化过程的影响研究

Morphological Configuration of CeO_(2) and Effect on Oxidation Process of 1,2-dichloroethane

采用一步水热法制备了不同形貌的CeO_(2),通过控制CeO_(2)的表观形貌实现其表面特定晶面((200)或(110))的暴露,从而有效调控材料表面Ce^(3+),Ce^(4+)和活性氧的浓度,提升材料中氧空位的浓度,增强CeO_(2)的低温可还原性能和表面晶格氧的移动能力。其中,暴露(111)晶面的球状CeO_(2)具有最快的低温反应速率和最佳的低温催化活性(T_(90)=368℃),加速1,2-二氯乙烷分子中C-Cl的活化转化,使1,2-二氯乙烷快速转化为碳酸盐和羧酸盐类物质,进而进一步深度氧化并完全转化为CO_(2)和H_(2)O等无害物质。

Different morphologies of CeO_(2) were prepared by a one-step hydrothermal method. By controlling the apparent morphology of CeO_(2) to achieve the exposure of its specific crystalline surface((200) or(110)), the concentration of Ce^(3+), Ce^(4+) and reactive oxygen on the material surface was regulated to increase the concentration of oxygen vacancies in the material and enhance the low-temperature reducibility of CeO_(2) and the mobility of surface lattice oxygen. Among them, the spherical CeO_(2) with exposed(111) crystal surface has the fastest low-temperature reaction rate and the best low-temperature catalytic activity(T_(90)=368 ℃), which can effectively promote the activated conversion of C-Cl in 1,2-dichloroethane molecules, resulting in the rapid combustion of 1,2-dichloroethane to carbonates and carboxylates, and then promote the deep oxidation process of 1,2-dichloroethane.