煅烧温度对γ-Fe_2O_3催化剂结构及其脱硝活性的影响  

Effects of Calcination Temperature on Selective Catalytic Reduction of NO_x overγ-Fe_2O_3 Catalysts Prepared with Microwave Assistance

作　　者：王栋[1,2] 张信莉[1] 彭建升[1] 路春美[1,2] 韩奎华[1,2] 徐丽婷[1] 

机构地区：[1]山东大学能源与动力工程学院,山东济南250061 [2]山东大学燃煤污染物减排国家工程实验室,山东济南250061

出　　处：《环境科学研究》2015年第5期808-815,共8页Research of Environmental Sciences

基　　金：国家自然科学基金项目(51276101);山东省自然科学基金项目(ZR2012EEM013);高等学校博士学科点专项科研基金项目(20120131110022)

摘　　要：采用沉淀-微波热解法,以Fe SO4·7H2O为铁源制备环境友好的γ-Fe2O3催化剂,结合XRD（X射线衍射）、N2等温吸附-脱附、SEM（扫描电子显微镜）、EDS（能谱仪）等手段对催化剂样品的晶相、孔结构、表面形貌、表面元素组成等进行表征,并考察其NH3-SCR（选择性催化还原）脱硝性能,研究煅烧温度对γ-Fe2O3催化剂物性及NH3-SCR脱硝性能的影响规律.结果表明：300、350和450℃下煅烧制备的催化剂中生成的杂质α-Fe2O3对SCR反应不利,而400℃煅烧制备的γ-Fe2O3催化剂脱硝性能最优,NOx转化率最高可达95%以上,XRD结果表明其纯度高,并且在60~100 nm孔径区间具有发达的孔隙结构,有利于SCR反应进行;随着煅烧温度升高,γ-Fe2O3催化剂表面晶格氧逐渐增加,颗粒形貌经历了片状颗粒（300、350℃）→球状颗粒（400℃）→针状颗粒（450℃）的变化过程,均匀的球状颗粒形貌及其表面丰富的晶格氧是400℃煅烧制得催化剂具备最优脱硝性能的重要因素.Environmentally-benign y-F%O3 SCR catalysts, using FeSO4＋ 7H20 as a ferrous source, were prepared under different calcination temperatures via the novel microwave pyrolysis. The catalytic activity for selective catalytic reduction （SCR） of NO by NH3 （NH3-SCR） was tested on a fixed-bed denitration reactor. X-ray diffraction （XRD）, N2 adsorption-desorption, scanning electron microscope （SEM） and energy dispersive spectrometer （EDS） were employed to investigate the effects of calcination temperature on the characterization of the 7-F%O3 catalysts. The results indicated that y-Fe2 03 catalysts calcined at 400 ℃ showed the best catalytic activity, with the highest NO, conversion above 95% . After being calcined at 300, 350 and 450 ℃ , tz-FezO3 would emerge from T-Fe203 , which was unfavorable to the SCR reaction. The catalyst calcined at 400 ℃ with high purity exhibited abundant pore structures with the diameter of 60-100 nm. With the calcination temperature increased from 300 ℃ to 450 ℃ , the lattice oxygen shifted to the surface of the catalyst and the surface morphology changed from lamellate （300 and 350 ℃ ） , then to spherical （400 ℃ ） , and eventually to acerose （450 ℃ ）. Homogeneous spherical particles and the surface lattice oxygen were principally responsible for the high catalytic activity for the catalyst calcined at 400 ℃.

关 键 词：选择催化还原 脱硝 催化剂 Γ-FE2O3 煅烧温度 微波 

分 类 号：X515[环境科学与工程—环境工程]