通过离子交换法合成了兼具很高的NO_x转化率和N₂选择性的Cu-SSZ-13分子筛催化剂，分别在700 ℃与800 ℃条件下对催化剂进行了16 h的高温水热老化处理，比较了水热老化前后催化剂的NO_x转化率、N₂选择性、NH₃吸附性能，分析了水热老化对Cu-SSZ-13分子筛催化剂NH₃-SCR性能的影响。采用XRD、BET、SEM等方法对催化剂进行了表征，并进一步利用in situ DRIFTS对老化前后的催化剂进行NH₃/NO吸附与反应的机理研究。结果表明：高温水热老化使得Cu-SSZ-13分子筛催化剂结晶度变差，比表面积及孔容减少；700 ℃老化处理后， Cu-SSZ-13分子筛催化剂仍具有较好的催化活性，并较好保留了分子筛的骨架结构，而800 ℃老化后，催化剂活性明显降低，催化剂骨架坍塌，表面生成较多减少催化剂活性位点的Cu_xO物种；高温水热老化使得催化剂上吸附于BrΦnsted酸性位点上NH₃减少，更多的NH₃以分子态吸附于催化剂表面，但总NH₃吸附量随着水热老化温度的升高而减少；同时，高温水热老化使得催化剂的NO吸附能力降低，但大部分吸附在催化剂表面的NO均被氧化为硝酸盐，且反应生成的各类硝酸盐占比同新鲜催化剂表面NO氧化反应后生成的硝酸盐比例基本相同，可见水热老化并未使Cu-SSZ-13分子筛催化剂的催化机理发生改变，为进一步改善催化剂的水热老化性能提供了可能。

A Cu-SSZ-13 molecular sieve catalyst was synthesized by the ion exchange method, which had a high NO_x conversion rate and N₂ selectivity. The NO_x conversion rate, N₂ selectivity and NH₃ adsorption performance were between the fresh and aged catalysts and the effect of hydrothermal aging on NH₃-SCR performance of Cu-SSZ-13 catalyst was analyzed after the preparation of aged catalysts through 16 h hydrothermal aging treatment at 700 ℃ and 800 ℃ respectively. The physicochemical properties of catalyst were characterized by using XRD, BET and SEM methods. The NH₃ and NO adsorption and reaction mechanism of catalyst before and after aging were investigated by the in situ DRIFTS. The results show that the hydrothermal aging will lead to the deterioration of Cu-SSZ-13 catalyst crystallinity and the reduction of specific surface and pore volume. The catalytic activity of Cu-SSZ-13 zeolite catalyst is still good and the skeleton structure is wellsustained after hydrothermal aging treatment at 700 ℃, but it becomes poor at 800 ℃, the catalyst skeleton collapses and more Cu_xO species forms on the active surface. The high-temperature hydrothermal aging leads to the reduction of NH₃ absorbed in Br-nsted acid location and the increase of NH₃ absorption on the catalyst surface. The total NH₃ adsorption reduces with the increase of water thermal aging temperature. In addition, the high-temperature hydrothermal aging leads to the weakening of NO adsorption capacity and most of the NO adsorbed on the surface of catalyst are oxidized to nitrate. The proportions of various nitrates are almost the same on the surface of fresh and aged catalyst. Accordingly, the hydrothermal aging does not change the catalytic mechanism of Cu-SSZ-13 molecular sieve catalyst, which make it possible to further improve the hydrothermal aging performance of catalyst.