【摘要】 采用柠檬酸络合-有机模板剂分解法制备了不同原子配比的La-Co-Ce-O混合氧化物催化剂.这些样品具有较大的比表面积(>100m2/g)和均匀的孔径(3·7~3·9nm),并显示出较高的热稳定性.模板剂分解法制备的样品中CeO2和Co3O4的分散性以及对CO和丙烷氧化的催化活性均明显优于传统共沉淀法制备的样品.催化剂活性并不与表面钴原子分数成正比,而与表面钴、铈物种间的协同效应密切相关,当表面钴、铈原子分数接近时,协同效应最佳,催化氧化性能最好.更多还原

【Abstract】 A series of La-Co-Ce-O mixed oxide catalysts with different bulk compositions were synthesized using a citric acid complexation-organic template decomposition method. The samples have high specific surface area （above 100 m²/g）, very uniform pore diameter （3.7～3.9 nm）, and good thermal stability. The dispersion of CeO₂ and Co₃O₄ crystallites in the samples prepared by the organic template decomposition is much higher than that by the conventional coprecipitation method. The samples prepared using this new method display much a higher activity for CO and propane oxidation than that by coprecipitation. The catalytic oxidation activity of the catalysts is not proportional to the number of the surface cobalt atoms, but is closely related to the synergism between the surface cobalt and cerium species. The catalytic synergetic effect is exhibited when the surface cobalt and cerium are in an atomic ratio nearly to one.更多还原