For Cu-exchanged zeolite catalysts, Cu²⁺ ions existing as Cu²⁺-2Z and [Cu(OH)]⁺-Z (where Z represents a framework negative charge) are considered the active sites for the selective catalytic reduction of NO_x with NH₃ (NH₃–SCR). Cu²⁺-2Z is more hydrothermally stable and sulfur poisoning-resistant than [Cu(OH)]⁺-Z. In this work, Cu-CHA and Cu-LTA catalysts containing only Cu²⁺-2Z species were successfully synthesized by a novel impregnation (NIM) method, exhibiting remarkably enhanced hydrothermal stability and sulfur resistance compared with any reported Cu-exchanged zeolite catalysts. It was also found that the [Cu(OH)]⁺-Z sites can convert to Cu²⁺-2Z by treating at high temperature (850 °C) due to the self-reduction of Cu²⁺ to highly mobile Cu⁺. The use of the NIM method not only significantly simplifies the preparation of the catalysts but also can precisely control the Cu loading, which is very important for the control of Cu species. Many other zeolite catalysts can be prepared by this method.

中文翻译：

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仅用 Cu2+-2Z 物种轻松合成 Cu 交换沸石催化剂：增强 NH3-SCR 的水热稳定性和耐硫性


对于铜交换沸石催化剂，以 Cu^2+-2Z 和 [Cu（OH）]⁺-Z（其中 Z 代表框架负电荷）存在的 Cu²⁺ 离子被认为是用 NH₃ （NH_3-SCR） 选择性催化还原 NO_x 的活性位点。Cu²⁺-2Z 比 [Cu（OH）]⁺-Z 更耐热液稳定性和抗硫中毒性。在这项工作中，通过一种新型浸渍 （NIM） 方法成功合成了仅包含 Cu²⁺-2Z 物种的 Cu-CHA 和 Cu-LTA 催化剂，与任何已报道的 Cu 交换沸石催化剂相比，表现出显着增强的水热稳定性和耐硫性。研究还发现，由于 Cu²⁺ 自还原为高流动性 Cu⁺，[Cu（OH）^]+-Z 位点可以通过高温 （850 °C） 处理转化为 Cu²⁺-2Z。使用 NIM 方法不仅大大简化了催化剂的制备，而且可以精确控制 Cu 负载，这对于 Cu 种类的控制非常重要。许多其他沸石催化剂可以通过这种方法制备。