过渡金属离子掺杂CeO_2-SO_4^(2-)固体酸的结构、redox性能、吸附性能及NH_3-SCR活性研究  

Structure,Redox,Adsorptive and NH_3-SCR Performances of Transition-Metal Ion Doped CeO_2-SO_4^(2-) Solid Acid Catalysts

作　　者：江洋[1] 司知蠢[1] 吴晓东[1] 马静[1] 马子然[1] 尉文超[1] 翁端[1] 

机构地区：[1]清华大学材料科学与工程系新型陶瓷与精细工艺国家重点实验室,北京100084

出　　处：《中国稀土学报》2011年第4期417-421,共5页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(50972069);"863"项目(2009AA06Z304)资助

摘　　要：通过溶胶凝胶法制备了Cux+,Fex+,Nix+和Zrx+掺杂的CeO2-SO42-固体酸NH3-SCR催化剂。利用XRD,IR,NH3-TPD,NH3-TPO,NOx-TPD和NO-TPO等手段研究了过渡金属离子掺杂对CeO2-SO42-催化剂结构、吸附性能、redox性能和NH3-SCR活性的影响。试验结果表明,Nix+和Zrx+掺杂的CeO2-SO42-固体酸催化剂的NH3-SCR活性最好,在250～360℃温度范围内NOx的转化率可达80%以上;Cux+掺杂催化剂的NOx和NH3吸附性能较差,导致催化剂的脱硝效率较低,而Fex+掺杂催化剂虽然具有较好的NH3和NOx吸附性能,但该催化剂对NH3的氧化性能较高,导致高温条件下还原剂的氧化,从而降低了CeO2-SO42-催化剂的活性;Nix+和Zrx+掺杂可以在提高催化剂吸附性能的基础上保持较低的NH3氧化活性,从而使CeO2-SO24-催化剂保持较高的脱硝性能。Cux＋,Fex＋,Nix＋ and Zrx＋ doped CeO2-SO42- solid acid NH3-SCR catalysts were prepared by sol-gel method.The catalysts were characterized by XRD,IR,NH3-TPD,NH3-TPO,NOx-TPD and NO-TPO.The results showed that Nix＋ and Zrx＋ doped CeO2-SO42- catalysts presented over 80% of NOx conversion at 250～360 ℃.The low NH3-SCR activity of Cux＋ doped catalyst was related with its low adsorption capacity of NH3 and NOx.The high ammonia oxidation activity of Fex＋ doped catalyst led to the low deNOx activity of catalyst.The Nix＋ and Zrx＋ ions might interact strongly with sulfates,leading to the high redox,adsorption properties and low ammonia oxidation activity of catalysts.Therefore,Nix＋ and Zrx＋ doped CeO2-SO42- catalyst presented higher NH3-SCR activity than those of Cux＋ and Fe3＋ doped catalysts.

关 键 词：CeO2-SO42-固体酸 过渡金属离子掺杂 NH3-SCR 稀土 

分 类 号：X511[环境科学与工程—环境工程]