磁性γ-Fe_2O_3催化剂NH_3-SCR脱硝反应动力学研究  

Kinetic Study of Selective Catalytic Reduction of NO_x by NH_3 on Magnetic γ-Fe_2O_3 Catalyst

作　　者：彭建升[1] 王栋[1] 张信莉[1] 路春美[1] 牛胜利[1] 李婧[1] 徐丽婷[1] 

机构地区：[1]山东大学,山东省济南市250061

出　　处：《中国电机工程学报》2015年第18期4690-4696,共7页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51276101);高等学校博士学科点专项科研基金项目(20120131110022);山东大学基本科研业务费专项资金项目(2015JC024)~~

摘　　要：采用沉淀法制备磁性γ-Fe2O3脱硝催化剂,通过瞬态动力学方法考察NH3、O2气体浓度对催化剂选择性催化还原(SCR)脱硝率的影响,在消除内外扩散阻力基础上应用稳态动力学研究方法构建SCR脱硝本征反应动力学模型。实验结果表明:NH3能快速在催化剂表面活性位上吸附活化;NO的吸附及其活性过渡中间体的形成在SCR反应中起控制作用;O2浓度小于1%时,其浓度的提高促进了磁性γ-Fe2O3催化剂SCR反应进行;在试验条件下,磁性γ-Fe2O3催化剂的NO、NH3、O2的反应级数分别为0.41、0、0.27,但当O2浓度>1%时,其反应级数为0,研究得到磁性γ-Fe2O3催化剂SCR表观反应活化能为28.77 k J/mol。Magneticγ-Fe2O3 catalysts were prepared by precipitation. The effect of NH3 and O2 on selective catalytic reduction （SCR） was investigated through the switching off and on method. And the intrinsic kinetics model for magneticγ-Fe2O3catalyst was built in the absence of internal and external diffusion by the way of steady-state dynamics. NH3 is absorbed and activated quickly on the active sites of catalyst surface; the adsorption of NO and the formation of its active transition species is the rate-determining step of SCR; the SCR reaction is promoted by O2 when it is less than 1%. It is also found that on the test condition the SCR reaction order with respect to NO, NH3, O2is 0.41,0 and 0.27 respectively, but the reaction order with respect to O2is 0 When O2 exceeds 1%.The derived apparent activation energy of magneticγ-Fe2O3 catalysts is 28.77 kJ/mol, which is much lower than the apparent activation energy of Vanadium titanium base catalyst.

关 键 词：脱硝 选择性催化还原(SCR) 磁性γ-Fe2O3 动力学 活化能 

分 类 号：TK09[动力工程及工程热物理]