摘要
采用沉淀氧化法制备了Co3O4/CeO2催化剂。分别在干、湿条件下进行了一氧化碳氧化反应研究。运用FT-IR表征手段,在钴铈复合氧化物上进行了CO吸附及CO/O2共吸附研究。结果表明,与纯的Co3O4样品相比,Co3O4/CeO2具有明显的抗湿气能力。Co3O4/CeO2催化剂在进行CO氧化时,表面形成了类碳酸盐物种。当环境温度低于453 K时,催化剂上类碳酸盐的生成与形成类碳酸盐物种后受热分解存在着动态平衡。当环境温度高于493 K,催化剂上生成的类碳酸盐物全部受热分解。氧化铈的加入提高了催化剂的抗湿气性能。较小粒径的Co3O4与CeO2产生的强相互作用可使CeO2向Co3O4提供氧,因而间接提供了CO氧化需要的氧。
Co3O4/CeO2 catalyst was prepared by co-precipitation-oxidation method.Adsorption of carbon monoxide and the co-adsorption of CO/O2 over Co3O4/CeO2 sample were investigated.In situ FT-IR analysis of the mechanism in CO oxidation was interpreted over Co3O4/CeO2 sample.Effects of the reaction conditions on the catalytic performance over Co3O4/CeO2 catalyst for carbon monoxide oxidation was investigated at humid and dry conditions.Results indicated that the addition of cerium to the cobalt oxide was beneficial for CO oxidation over Co3O4 at humid condition.The formation of carbonate species with reaction on Co3O4/CeO2 composite oxide slightly deactivated the catalyst.When the temperature was as low as 453 K,the dynamic equilibrium of formation and decomposition of carbonate species existed in Co3O4/CeO2 composite oxide catalyst.The carbonate species disappeared above 493 K.The strong interaction between CeO2 and Co3O4 may contribute to the excellent water resistance for low-temperature CO oxidation over Co3O4/CeO2 catalyst at humid condition.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2012年第2期229-234,共6页
Journal of Fuel Chemistry and Technology
基金
中国博士后科学基金(20100471808)
