Cu-SAPO-56, a potential catalyst for the selective catalytic reduction of NOx by NH₃

A novel Cu-exchanged catalyst, Cu-SAPO-56 prepared by direct ion exchange method, was studied for NH3-SCR reaction. Cu-SAPO-56 exhibits excellent NH3-SCR activity and hydrothermal stability. The NOx conversion of CuSAPO-56 maintains more than 90 % at a wide temperature range between 250 C and 400 C even after a rigorous steam treatment (800 C for 16 h or 50 C for 24 h). The isolated Cu2+ ions located in double 6-ring of AFX structure are determined as the catalytic active sites. Both of Cu content and Si content in Cu-SAPO-56 play critical roles in NH3-SCR activity and hydrothermal stability. The excellent catalytic performance and strong hydrothermal stability exhibits the huge application potential of Cu-SAPO-56 for NH3-SCR reaction.