Efficient one-pot synthesis of Cu-SAPO-34 catalysts for NH₃-SCR of NO_x

Cu-SAPO-34 shows high catalytic performance in ammonia selective catalytic reduction (NH₃-SCR) of nitrogen oxides (NO_x). Complex synthesis methods and environmental pollution limited the development of Cu-SAPO-34. Therefore, a new method for preparing Cu-SAPO-34 catalysts is proposed. A series of novel Cu-SAPO-34 catalysts have been synthesized by one-pot hydrothermal method. Aluminum phosphate was used as phosphorus and aluminum source to form the initial gel with the complex formed by Cu species and tetraethylenepentamine (TEPA). The novel Cu-SAPO-34 catalysts with different Cu content were prepared and characterized by XRD, UV–vis spectrum, H₂-TPR, NH₃-TPD and XPS. It is considered that there are Cu²⁺ species in the novel Cu-SAPO-34 catalysts and its proportion were analyzed. The three Cu-SAPO-34 catalysts with different Cu content have different NH₃-SCR catalytic activity. And compared with conventional Cu-SAPO-34 catalyst with phosphoric acid as phosphorus source, one-pot synthesized Cu-SAPO-34 catalysts with different Cu content have more excellent NH₃-SCR catalytic activity at high temperature.