煅烧温度对Mn改性γ-Fe_2O_3催化剂结构及低温SCR脱硝活性的影响  

Influence of calcination temperature on structural property of Mn doped γ-Fe_2O_3 catalysts and low-temperature SCR activity

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

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：《燃料化学学报》2015年第2期243-250,共8页Journal of Fuel Chemistry and Technology

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

摘　　要：采用共沉淀法,在不同煅烧温度下制备一系列Mn改性γ-Fe2O3催化剂（Fe0.7M n0.3Oz）,研究了煅烧温度对Fe0.7M n0.3Oz催化剂低温SCR脱硝活性的影响,并借助XRD、N2吸附-脱附、EDS及SEM等手段对催化剂进行表征。结果表明,350℃煅烧所得Fe0.7M n0.3Oz催化剂的低温SCR活性最佳,在70℃时取得92%的NOx转化率,100~200℃可维持100%的NOx转化率,而450℃煅烧所得催化剂的低温SCR活性最低;煅烧温度为350℃时,催化剂具有最大的比表面积和比孔容、发达的孔隙结构及适当结晶度的γ-Fe2O3,而煅烧温度为400或450℃时,催化剂发生烧结且有α-Fe2O3生成,不利于低温SCR反应的进行,因此,Fe0.7M n0.3Oz催化剂的最佳煅烧温度为350℃。A series of Mn doped γ-Fe2O3catalysts（ Fe0.7Mn0.3Oz） were prepared with different calcining temperatures via a coprecipitation method,and the influences of calcination temperature on the low-temperature selective catalytic reduction（ SCR） activity of Fe0.7Mn0.3Ozcatalysts were investigated.The catalysts were characterized by N2adsorption-desorption,X-ray diffraction（ XRD）,scanning electron microscope（ SEM）,and energy dispersive spectrometer（ EDS）.The results indicate that Fe0.7Mn0.3Ozcatalysts calcined at 350 ℃exhibit the best low-temperature SCR activity,and the NOxconversion reaches above 90% at 70 ℃ and 100% at100 ~ 200 ℃,while the catalysts calcined at 450 ℃ showa poor low-temperature SCR activity.When the calcination temperature is 350 ℃,the catalysts possess the highest specific surface area and pore volume,flourishing pore structure and appropriate γ-Fe2O3 crystallinity.However,when the calcination temperature is increased to 400 or 450 ℃,the sintering takes place and α-Fe2O3 appears in Fe0.7Mn0.3Ozcatalysts,which is unfavorable to the low-temperature SCR reaction.Therefore,350 ℃ is recommended as the optimum calcination temperature for Fe0.7Mn0.3Ozcatalysts.

关 键 词：低温选择性催化还原 催化剂 煅烧温度 Γ-FE2O3 Mn 

分 类 号：X701[环境科学与工程—环境工程]