n(硅)/n(铝)对Cu-SAPO-34催化剂C3H6-SCR性能的影响

Effect of the SiO_2/Al_2O_3 Ratio on the C_3H_6-SCR Performance of the Cu-SAPO-34 Catalysts

Cu-SAPO-34分子筛是一种高性能氮氧化物选择催化还原(SCR)催化剂,其载体SAPO-34对催化剂的氮氧化物催化消除活性有重大影响。采用水热合成法制备了n(硅)/n(铝)为0.4、0.6和0.8的SAPO-34分子筛,X射线粉末衍射(XRD)和扫描电子显微镜(SEM)结果表明随着n(硅)/n(铝)的增大SAPO-34分子筛的结晶度增高,粒度减小;氨气程序升温脱附(NH3-TPD)结果显示n(硅)/n(铝)为0.8时分子筛的酸量最大。综上所述,n(硅)/n(铝)为0.8时Cu-SAPO-34催化剂表现出最佳的丙烯选择性催化还原(C3H6-SCR)性能。

Cu-SAPO-34 is a promising NOx selective catalytic reduction （SCR） catalyst. Its support, the SAPO-34 zeolite, has great effect on the catalytic performance of De-NOx. In this work, the SAPO-34 ze-olites with the SiOJA1203 ratio of 0.4, 0.6 and 0. 8 were synthesized by a hydrothermal process. X-ray diffraction （XRD） and scanning electron microscopy （SEM） results show that the crysta｜linity of the SA-PO-34 zeolites was improved with the increasing of the SiO2/A1203 ratio; and NH3 temperature-pro- grammed desorption （ NH3-TPD） results indicate that the number of the acid sites is largest when the SiO2/Al2O3 ratio is 0. 8. As a result, the Cu-SAPO-34 catalyst synthesized with the SiO2/Al2O3 ratio of 0. 8 presented the highest C3H6 selective catalytic reduction （C3H6-SCR） performance.