Ce、Zr改性Mn/ZSM-5分子筛催化剂对C_3H_6-SCR反应性能的影响  

Influence of Ce and Zr Modified Mn/ZSM-5 Catalyst on C_3H_6-SCR Reaction Performance

作　　者：张川[1,2] 郭芳 许俊强[1] 秦娅华[1] 谢家庆 ZHANG Chuan;GUO Fang;XU Junqiang;QIN Yahua;XIE Jiaqing(College of Chemistry and Chemical Engineering,Chongqing University of Technology,Chongqing 400054,China;College of Chemistry and Chemical Engineering,Sichuan Institute of Technology,Zigong 643000,Sichuan,China;China Coal Technology Engineering Group Chongqing Research Institute,Chongqing 400039,China)

机构地区：[1]重庆理工大学化学化工学院,重庆400054 [2]中煤科工集团重庆研究院有限公司,重庆400039 [3]四川理工学院化学化工学院,四川自贡643000

出　　处：《硅酸盐学报》2019年第4期486-493,共8页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(21206202);重庆市重点产业共性关键技术创新专项(cstc2016zdcy-ztzx0020-02);四川省科技计划项目(2017GZ0421);重庆市第五批高等学校优秀人才计划项目(2017-28);重庆市研究生科研创新项目(CYS17283);重庆市巴南区科技计划项目(2017TJ10;2018TJ03)

摘　　要：采用浸渍法制备了一系列Ce、Zr改性Mn/ZSM-5分子筛催化剂,对其C_3H_6-SCR(选择性催化还原)反应性能进行了评价,研究了Ce、Zr的引入对Mn/ZSM-5分子筛催化剂选择催化还原NO的影响,并采用X射线衍射、比表面积测量、扫描电子显微镜、NH_3-程序升温脱附(TPD)、H_2-程序升温还原(TPR)等表征手段对催化剂的物理化学性质进行了表征。结果表明:Ce、 Zr改性Mn/ZSM-5分子筛催化剂C_3H_6-SCR反应中表现出较为优异的催化活性,最优配比的20%Mn-7%Ce-1%Zr/ZSM-5催化剂在200℃、30000h^(-1)的空速下,催化剂的最大脱硝效率达到87%,且操作温度窗口T50=150～380℃。活性组分Mn以MnO_2和Mn_2O_3形式存在,且与助剂Ce、Zr高度分散在催化剂表面,而且形成协同作用;催化剂表面的弱酸和中强酸和氧化还原性能的增强有利于C_3H_6-SCR低温催化活性的提高。A series of Ce,Zr modified Mn/ZSM-5 molecular sieve catalysts were prepared by an impregnation method,and the C3H6-selective catalytic reduction(SCR)reaction performance was evaluated.The effects of Ce and Zr on the SCR of NO on Mn/ZSM-5 molecular sieve catalyst were investigated.The physical and chemical properties of the catalysts were characterized by X-ray diffraction,specific surface area measurement,scanning electron microscopy,NH3-temperature programmed desorption(TPD),and H2-TPR,respectively.The results show that Ce and Zr modified Mn/ZSM-5 molecular sieve catalyst shows an excellent catalytic activity in the C3H6-SCR reaction.At 200℃and a space velocity of 30 000 h^-1,the optimal ratio of 20%Mn-7%Ce-1%Zr/ZSM-5 catalyst has a maximum NO conversion of 87%and NO conversion of>50%at 150-380℃in a wide operating temperature range.The active component Mn exists in the forms of MnO2 and Mn2O3.Mn,Ce and Zr are mainly dispersed on the catalyst surface and form a synergy.The weak acid and moderate acidity of the catalyst surface and the enhancement of the redox properties are beneficial to the improvement of low-temperature catalytic activity in C3H6-SCR.

关 键 词：分子筛催化剂 选择催化还原 丙烯 改性 低温活性 

分 类 号：TQ170.9[化学工程—硅酸盐工业]