为了考察制备方法对Cu-SSZ-13催化剂在氨选择性催化还原NO_x(NH_3-SCR)中催化性能的影响,使用不同的方法和载体,制备出理化性质有明显差异的3种催化剂(Cu_(3.9)-Na_(0.8)-SSZ-13、Cu_(5.1)-H-SSZ-13和Cu_(4.0)-Na_(4.0)-SSZ-13),并考察3种催化剂的水热稳定性和抗硫中毒性能.结果表明,由于具有适宜的Cu负载量,并且Cu物种的稳定性极高,一步合成法制备的Cu_(3.9)-Na_(0.8)-SSZ-13催化剂的水热稳定性优于液相离子交换法制备的两种催化剂.而以H-SSZ-13为载体,液相离子交换法负载Cu物种制备的Cu_(5.1)-H-SSZ-13催化剂具有最优的抗硫中毒能力,这与其较多的酸性位有关.因此,含有较多酸性位并且活性物种稳定性高是制备水热稳定性和抗硫中毒能力较优的Cu-SSZ-13催化剂的关键.
In order to investigate the effect of preparation method on the performance of Cu-SSZ-13 in selective catalytic reduction of NOxwith ammonia( NH_3-SCR),three different Cu-SSZ-13 catalysts( Cu_(3.9)-Na_(0.8)-SSZ-13,Cu_(5.1)-H-SSZ-13 and Cu_(4.0)-Na_(4.0)-SSZ-13) were prepared based on different methods and supporters. The hydrothermal stability and sulfate durability of the three catalysts were tested. Due to the suitable Cu content and excellent stability of Cu species,the catalyst( Cu_(3.9)-Na_(0.8)-SSZ-13) prepared by one-pot synthesis method shows the best hydrothermal stability. Cu_(5.1)-H-SSZ-13 prepared by liquor ion exchange method based on H-SSZ-13 supporter shows the best sulfate durability,which might be related to the more acid sites.Therefore,much acid sites and excellent stability of active species were the key factors for the Cu-SSZ-13 with high hydrothermal stability and sulfate durability.