CeO_(2)负载Co或Mn棒状复合材料对CO的催化氧化

Catalytic Oxidation of CO by CeO_(2) Supported Co and Mn Rod-like Composites

用一步水热法制备了CeO_(2)负载的不同比例过渡金属(Co,Mn)棒状纳米材料,通过X射线衍射仪、扫描电子显微镜、透射电子显微镜、Raman光谱仪、X射线光电子能谱仪、BET比表面分析仪、H_(2)程序升温还原和CO程序升温脱附表征并分析了引入不同含量过渡金属(Co,Mn)对催化剂的晶格常数、表面不同价态元素含量、比表面积和CO催化氧化性能等的影响。此外,CeO_(2)负载的过渡金属(Co,Mn)相比于纯相CeO_(2)表现出更加优异的催化活性。Co-CeO_(2)催化氧化50%CO的温度(T_(50%))范围为97~133℃,Mn-CeO_(2)为107~195℃,其中,含有40%(摩尔分数)Co或Mn的Co-CeO_(2)和Mn-CeO_(2)表现出最佳的催化性能,T_(50%)分别为97℃和107℃。过渡金属(Co,Mn)的引入,使得催化剂表面的相互协同作用增强,产生更多的活性氧,从而有效地提高了材料的催化活性。

The transition metals(i.e.,Co,Mn)supported rod-like CeO_(2) nanomaterials with different proportions were prepared by an one-step hydrothermal method.The influence of transition metals(Co,Mn)content on the crystal lattice constant,element content of different valence states of the catalyst,specific surface area and CO catalytic oxidation performance were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,Raman spectroscopy,X-ray photoelectron microscopy,specific surface area analysis,H_(2)-temperature programmed reduction and CO-temperature programmed desorption,respectively.In addition,compared to pure CeO_(2),CeO_(2) nanorods supported Co or Mn show a greater catalytic activity for CO at a low temperature.The temperature range of Co-CeO_(2) with catalytic oxidation CO of 50%(T_(50%))is 97-133℃,and that of Mn-CeO_(2) is 107-195℃.Co-CeO_(2) and Mn-CeO_(2) with 40%(in mole fraction)of Co or Mn show the optimum catalytic performance,and the T_(50%) of 40% Co-CeO_(2) is 97℃ and 40% Mn-CeO_(2) is 107℃,respectively.The introduction of transition metal(Co,Mn)enhances the synergistic effect on the catalyst surface and produced more active oxygen,thus effectively enhancing the catalytic oxidation performance of the nanomaterials.