自蔓延高温燃烧合成法制备CeWTiO_x催化剂及其NH_3-SCR性能  

Preparation of CeWTiO_x catalysts via self-propagating high temperature synthesis and its NH_3-SCR performance

作　　者：卢朋[1] 鲁卫哲 李欢[1] 陈银飞[1] 张泽凯[1] 

机构地区：[1]浙江工业大学化学工程学院能源化学工程系,浙江杭州310014

出　　处：《燃料化学学报》2017年第8期986-992,共7页Journal of Fuel Chemistry and Technology

摘　　要：采用自蔓延高温燃烧合成法制备了CeWTiO_x系列催化剂并考察了其氨选择性催化还原NO_x(NH_3-SCR)性能。利用X射线衍射、N_2吸附-脱附、H_2程序升温还原、X射线光电子能谱、NH_3程序升温脱附表征和分析了催化剂晶相、结构、氧化还原能力和酸性强度与其活性之间的关系。结果表明,Ce_(40)W_(10)TiO_x催化剂在150-430℃NO转化率可达80%以上,含硫条件下200℃NO转化率可保持在97%左右。结果表明,该催化剂的低温活性和抗硫性能主要与W的掺杂有关。钨的存在减弱了Ce-O键的强度,降低了CeO2的结晶度和减小了晶粒粒径,增加了催化剂表面活性氧含量和酸量,提高了其性能。A series of CeWTiOx catalysts were prepared by self-propagating high-temperature synthesis method,and their NH3-SCR activities were evaluated. X-ray diffraction,N2 adsorption-desorption,H2-temperatureprogrammed reduction,X-ray photoelectron spectroscopy and NH3-temperature-programmed desorption were performed to investigate the relationship between the catalyst activity and its physicochemical properties such as crystalline phase,specific surface area,redox ability and acidity. The results showed that 80% of NO conversion could be reached on the Ce40W10 TiOx catalyst sample in a range of 150-430 ℃. NO conversion of Ce40W10 TiOx could be kept above 97% in SO2 atmosphere. The characterization indicated that the excellent low temperature activity and SO2 resistance of Ce40W10 TiOx were mainly associated with the tungsten doping. The existence of tungsten weakened the strength of Ce-O bond,lowered the crystallinity and crystal size of CeO2,increased the surface active oxygen content and the acid sites,thus improved the NH3-SCR performance of the catalyst.

关 键 词：自蔓延高温燃烧合成法 CeWTiOx 钨 抗硫 

分 类 号：X511[环境科学与工程—环境工程]