微波热解制备γ-Fe_2O_3催化剂及其SCR脱硝性能  

Microwave-assisted preparation of γ-Fe_2O_3 as SCR catalysts

作　　者：王栋[1,2] 张信莉[1] 路春美[1,2] 韩奎华[1,2] 彭建升[1] 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]燃煤污染物减排国家工程实验室(山东大学),山东济南250061

出　　处：《化工学报》2014年第12期4805-4813,共9页CIESC Journal

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：以Fe SO4·7H2O[Fe(NO3)3·9H2O]为铁源,采用新型微波热解法制备γ-Fe2O3[α-Fe2O3]催化剂样品,通过XRD、N2等温吸附-脱附、压汞法等实验手段对催化剂样品晶相、微观孔结构等进行表征;考察两种催化剂样品的NH3-SCR脱硝性能,通过归一化处理得到两种催化剂在不同温度下的本征脱硝反应速率,同时对比研究了γ-Fe2O3与钒系催化剂的脱硝活性;研究氨氮比、氧浓度等运行参数对γ-Fe2O3催化剂NH3-SCR脱硝性能的影响规律,并对其抗硫抗水性能进行考察。结果表明:采用新型微波热解法可得到纯度较高的γ-Fe2O3催化剂,其介孔分布合理且大孔数量丰富;同时γ-Fe2O3催化剂表现出优于α-Fe2O3催化剂的脱硝性能,400℃时最大NOx转化率达到96%,300、325、350℃下单位面积脱硝速率达到α-Fe2O3催化剂的3倍左右;γ-Fe2O3催化剂具备优良的抗硫抗水性能,其最佳氨氮比为1、最佳氧体积分数为3.5%。γ-Fe_2O_3 and α-Fe_2O_3 catalysts were prepared respectively via a novel microwave pyrolysis method using FeSO_4 ·7H_2O and [Fe（NO_3）_3·9H_2O] as ferrous source. Crystalline phase and microstructure of catalysts were characterized by X-ray diffraction （XRD） , mercury intrusion porosimetry （MIP） , N2 adsorption-desorption and NH3-SCR activity of different catalysts were investigated. SCR reaction rates over the catalysts at different temperatures were obtained by unitary processing, and SCR activities over γ-Fe_2O_3 and vanadium-based catalysts were compared. The effects of O_2 concentration, molar ratio of NH_3/NO, SO_2, and H_20 on SCR activity of γ-Fe_2O_3 catalyst were also studied. Pure γ-Fe_2O_3 catalyst could be obtained via this novel microwave pyrolysis method, and showed higher crystallinity than γ-Fe_2O_3 catalyst, γ-Fe_2O_3 catalyst had broader pore size distribution as well as appropriate ratios of mesopores and macropores. Meanwhile, γ-Fe_2O_3 catalyst exhibited better SCR activity than γ-Fe_2O_3 catalyst. The highest NO_x conversion of γ-Fe_2O_3 catalyst was up to 96% at 400℃ and SCR reaction rates normalized by surface area were three times higher than that of γ-Fe_2O_3 catalyst at 300, 325 and 350℃, respectively. The optimum molar ratio of NH3/NO and 02 concentration for selective catalytic reductionover γ-Fe_2O_3 catalyst were recommended to be 1 and 3.5% （vol）, respectively.

关 键 词：Γ-FE2O3 催化剂 微波 热解 选择催化还原 脱硝 

分 类 号：X551[环境科学与工程—环境工程]