新型铜铈复合材料的制备及其脱硝性能的研究

分别采用浸渍法和沉淀-水热法制备了CuO/CeO2复合催化剂.通过X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、X射线能谱分析(EDX)、N2吸附-脱附测试(BET)等手段对样品进行了表征.沉淀-水热法制备的CuO/CeO2复合材料具有更好的结晶性，而浸渍法制备的复合材料上CuO主要以无定形态存在.两种复合材料中CuO颗粒的尺寸较复合前明显减小且分散均匀.沉淀-水热法制备的复合材料颗粒间结合紧密，形成连通的孔结构，而浸渍法制备的复合物孔径分布较窄.测定了不同的反应温度下复合材料催化丙烯还原NO的转化率(C3H6-SCR).结果表明，两种方法制备的CuO/CeO2复合催化剂都表现出优于单组分CuO和CeO2的催化活性，其中沉淀-水热法制备的催化剂较浸渍法制备的催化剂表现出更强的协同作用，350℃时NO转化率可达74%.其可能的原因是，沉淀-水热法能使得复合材料上的CuO物种更均匀地分散在CeO2表面并与之充分接触，使材料整体形成更有利于多相反应的介孔结构从而增强了协同作用，提高了材料催化活性.

Preparation of novel Cu-Ce composited material and its performance of deNOx

CuO/CeO2 composited catalysts were successfully synthesized by impregnation and precipitate-hydrothermal method， respectively. The prepared samples were characterized by powder X-Ray diffraction (XRD)， scanning electron microscopy (SEM)， energy dispersive X-Ray spectroscopy (EDX) and N2 adsorption-desorption measurements. The CuO/CeO2 composites prepared by precipitate-hydrothermal method exhibited better crystallinity than that prepared by impregnation which mainly existed in amorphous state. Both types of CuO nanoparticles were well dispersed on the surface of CeO2 and the corresponding size obviously decreased. The CuO/CeO2 composite prepared by precipitate-hydrothermal method formed an even and compact mesoporous structure with interconnected pore channels， while the composited catalyst prepared by impregnation had a narrow pore size distribution. The deNOx activities of C3H6-SCR over different catalysts were tested under different temperatures. The results indicated that both the composited catalysts prepared by different methods showed higher catalytic activities than that of single component. Moreover， the composited material prepared by precipitate-hydrothermal method exhibited stronger synergistic effect with the maximum NO conversion rate of 74% at 350 ℃. It was probably due to the well dispersion of CuO species on CeO2 surface， promoting the formation of a special porous structure. It is beneficial for the heterogeneous catalytic reaction， amd thus enhancing the synergistic effect and catalytic activities.