The cold start wetting effect on Cu-SSZ-13 has been simulated via soaking catalysts with various Si/Al ratios in ammonium water at disparate pH levels. It is found that a mild treatment (pH = 9) has little effect on the selective catalytic reduction of NO_x with NH₃ performance of Cu-SSZ-13. However, on increasing the pH to 12, the deNO_x activity and resistant ability to hydrothermal aging decrease obviously. Such a decrease could be attributed to the desilication phenomenon during the soaking process, which results in a number of effects including extraction of Cu²⁺ ions from the exchange sites, decrease in acidity, and damage to the zeolite structure. Meanwhile, the alkaline treatment exhibits distinct impacts on the physicochemical properties of Cu-SSZ-13 with different Si/Al ratios. The low Si/Al ratio catalyst (Si/Al-6) is insusceptible to desilication because of a higher content of the AlO₄^– structure and extra-framework Al (Al_ef), which could hamper the desilication.

中文翻译：

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冷启动润湿对Cu-SSZ-13 NH ₃ -SCR催化剂催化性能和水热稳定性的影响

通过在不同的pH值下将具有各种Si / Al比的催化剂浸泡在铵水中，可以模拟出对Cu-SSZ-13的冷启动润湿效果。发现温和的处理（pH = 9）对Cu-SSZ-13具有NH ₃性能的NO _x的选择性催化还原几乎没有影响。然而，在pH值提高到12，DENO _X的活性和耐药能力的水热老化下降明显。这种减少可能归因于浸泡过程中的硅化现象，从而导致许多影响，包括提取铜²⁺来自交换位点的离子，降低酸度，并破坏沸石结构。同时，碱处理对不同Si / Al比的Cu-SSZ-13的理化性质有明显的影响。低Si / Al比催化剂（的Si / Al-6）是因为较高含量的所述的AlO的不易受到脱硅₄ ^-结构和骨架外的Al（铝_EF），这可能会妨碍脱硅。