采用共沉淀法制备了n(Co):n(Mn):n(Al)=4:0:2、4:1:1、4:2:0的CO3^2-离子插层层状双金属氢氧化物(LDHs),经500℃煅烧4h得到相应的Co-Mn-Al复合过渡金属氧化物。利用X射线衍射(XRD)、X射线荧光光谱分析(XRF)、Nz吸附脱附、透射电镜(TEM)技术对样品进行了表征。研究结果表明,Co-Mn-Al复合氧化物具有合Co尖晶‘石氧化物的结构特征,属于中孔材料,与Co-Mn-Al LDHs相比,其比表面积增大,孔容增加,孔径尺寸变小,且随着Mn与Al原子比的增加,样品结晶度及有序性均下降。
Co-Mn-A1-CO3 layered double hydroxides (LDHs) with Co : Mn : Al molar ratios of 4 : 0 : 2, 4 : 1 : 1 and 4 : 2 : 0 were prepared by coprecipitation method. The mixed transitional metal oxides were obtained by calcination of the prepared LDHs at 500℃ for 4 h. X-ray diffraction (XRD), X-ray fluorescence (XRF), N2 adsorption-desorption and transmission electron microscopy (TEM) were used to characterize the precursors and the related mixed oxides. Co-based spine structure was detected in Co-Mn-Al mixed oxides. Compared with the LDH precursors, the specific surface area and pore volume of the corresponding mixed oxides increased greatly and the pore distribution was narrower. With the increase of Mn/Al molar ratio, the degree of crystallinity and the ordered morphologies de- creased.