中文摘要：

采用吸附相反应技术制备得到了MnOx/CeO2/SiO2催化剂，通过X射线衍射（XRD）、透射电子显微镜（TEM）、高分辨透射电子显微镜（HRTEM）、紫外激光拉曼（Raman）等手段对催化剂进行了表征。 HRTEM分析表明活性组分MnOx与CeO2都均匀分布在载体SiO2表面；XRD分析表明Mn3O4特征峰随着CeO2含量的增加逐渐减小至完全消失， CeO2的加入降低了MnOx的结晶程度，增加了MnOx的分散性；Raman光谱表明催化剂表面的Mn离子能够进入CeO2晶格，激发出空穴氧，随着CeO2负载量的增加，催化剂氧空穴浓度先升高后降低。以NH3为还原剂，考评催化剂的NOx低温选择性催化还原（SCR）性能，催化剂催化活性随CeO2负载量增加先升高后降低，与催化剂氧空穴浓度变化规律一致，说明催化剂活性受氧空穴浓度影响，氧空穴浓度升高，催化剂催化活性升高。

英文摘要：

MnOx/CeO2/SiO2 catalysts were prepared by the adsorption phase reaction technique and were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM）, and Raman spectroscopy. HRTEM showed that MnOx and CeO2 particles were uniformly coated on the surface of SiO2. The XRD spectra showed that the intensity of the Mn3O4 diffraction peaks gradual y decreased and then completely disappeared with the increasment of the CeO2 content, which indicated that CeO2 reduced the crystal inity of MnOx and improved the dispersibility of MnOx. Raman spectroscopy indicated that Mn ions on the surface of catalysts could enter into the lattice of CeO2, replace oxygen ions, and form oxygen vacancies. With the increasment of CeO2 content, the density of oxygen vacancies initial y increased and then decreased. We used the catalysts for selective catalytic reduction （SCR） of NOx with NH3. The catalytic activity initial y increased and then decreased with the increasment of CeO2 content, similar to the change in the density of oxygen vacancies. Thus, the catalytic activity of the MnOx/CeO2/SiO2 catalysts increases with increasing the density of oxygen vacancies.