基于NH3-SCR的CeO2-TiO2复合氧化物催化剂：结构与脱硝性能  

CeO_2-TiO_2 Mixed Oxides Catalysts for Selective Catalytic Reduction of NO_x with NH_3:Structure-properties Relationships

作　　者：孙向丽[1] 何洪[2,1,3] 苏垚超 闫京芳 宋丽云[2,1] 邱文革[2,1] 

机构地区：[1]北京工业大学绿色催化与分离北京市重点实验室,北京100124 [2]北京工业大学区域大气复合污染防治北京市重点实验室,北京100124 [3]北京电动车辆协同创新中心,北京100081

出　　处：《高等学校化学学报》2017年第5期814-822,共9页Chemical Journal of Chinese Universities

基　　金：国家重点研发计划(批准号:2016YFB0600405);国家自然科学基金(批准号:21577005,21277009)资助~~

摘　　要：以TiOSO_4·2H_2O和Ce(NO_3)_3·6H_2O为前驱体,采用共沉淀法制备了不同CeO_2含量的CeO_2-TiO_2复合氧化物催化剂.对样品结构进行了表征,考察了催化剂的NH_3-SCR(NH_3选择性催化还原)反应活性、N_2选择性和抗水抗硫性能.结果表明,随着催化剂中CeO_2含量的增加,催化剂的物相结构、晶粒尺寸及脱硝性能均出现规律性变化,这种改变与样品的酸碱性和氧化还原性能的变化有关.当样品中CeO_2的质量分数约为50%时,催化剂的结构呈无定形态,具有较大的比表面积和较多的氧空位,有利于反应物分子在催化剂表面的吸附和活化,拓宽了催化剂的低温活性窗口并提高了NO的转化率.A series of CeO2-TiO2 mixed oxides catalysts prepared by Co-precipitation method was investigated on selective catalytic reduction （SCR） of NOx with NH3. The properties of the catalysts were characterized using XRD, BET, XRF, XPS, Hz-TPR, NH3-TPD and NO＋O2-TPD techniques. The results indicated that the crystal structure, crystallite size and catalytic NH3-SCR activity over the catalysts presented a regular change with the increase of CeO2 concentration. Particularly, the 50CeTi catalyst with amorphous structure of CeOz-TiO2 showed a higher BET surface area and a stronger surface acidity than other samples. Meanwhile, favorable Ce3＋ and the surface adsorbed oxygen benefited the adsorption of NOx and NH3 molecules, which enhanced DeNOx performance.

关 键 词：选择性催化还原 CE O2-Ti O2复合氧化物 氮氧化物 物相结构 

分 类 号：O643[理学—物理化学]