不同形貌氧化铈上负载氧化锰低温NH_3-SCR催化剂的活性研究  

Study on NH_3-SCR activities of MnO_2 catalysts supported on CeO_2 with different morphology

作　　者：邵晔 虞硕涵[1,2,3,4] 高飞 董林 SHAO Ye;YU Shuohan;GAO Fei;DONG Lin(School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China;Key Laboratory of Mesoscopic Chemistry of MOE, Nanjing University, Nanjing 210093, China;Center of Modern Analysis, Nanjing University, Nanjing 210093, China;Jiangsu Key Laboratory of Vehicle Emissions Control, Nanjing University, Nanjing 210093, China)

机构地区：[1]南京大学化学化工学院,南京210093 [2]南京大学介观化学教育部重点实验室,南京210093 [3]南京大学现代分析中心,南京210093 [4]南京大学江苏省机动车尾气污染控制重点实验室,南京210093

出　　处：《中国科技论文》2017年第21期2406-2412,共7页China Sciencepaper

基　　金：高等学校博士学科点专项科研基金资助项目(20130091110055);江苏省科技支撑计划项目(BE2014130);国家高技术研究发展计划资助项目(2015AA03A401)

摘　　要：为了研究氧化铈载体形貌对负载氧化锰催化剂低温NH3-SCR催化活性的影响,通过浸渍法制备了棒状、八面体、立方块3种不同形貌的氧化铈上负载氧化锰的NH3-SCR催化剂。NH3-SCR活性结果表明,立方块氧化铈上负载氧化锰催化剂具有最好的SCR活性与N2选择性。通过X射线衍射(X-ray diffraction,XRD)、透射电子显微镜(transmission electron microscopy,TEM)、光电子能谱(X-ray photoelectron spectroscopy,XPS)、H_2程序升温还原(H_2-temperature programed reduction,H_2-TPR)、NH3-程序升温脱附(NH3-temperature programmed desorption,NH3-TPD)、傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)表征证明,立方块氧化铈上负载氧化锰催化剂表面具有更多的表面高价铈。这些表面高价铈能氧化吸附催化剂表面的NH3、NO分子形成NH_2活性中间体和NO_2。原位生成的NO_2可以促使催化剂表面SCR反应按照"fastSCR"途径进行,从而提升催化剂的低温活性。To investigate the influence of support morphology on NH3SCR activities of MnO2catalysts supported on CeO2,Rob,octahedron andcube shape CeO2supporting MnO2catalysts were successfully synthesized by the immersion method.The results of NH3SCR activity show that Cube like CeO2supporting MnO2exhibitsthe best activity and N2selectivity.According to the results of X ray diffraction(XRD),transmission electron microscopy(TEM),X ray photoelectron spectroscopy(XPS),H2temperature programed reduction(H2TPR),NH3temperature programmed desorption(NH3TPD),Fourier transform infrared spectroscopy(FTIR),cube like CeO2supporting MnO2hasmore Ce4+ions on its surface,which canoxidize absorbed NH3and NO on catalyst surface to-NH2and NO2.NO2canenhance the catalytic activity of cube like CeO2supporting MnO2via making NH3SCR on catalyst proceed through a“fast SCR”pathway.

关 键 词：环境催化 氧化铈 NH3SCR 晶面 

分 类 号：O643.36[理学—物理化学]