Cu-Sapo-56, a Potential Catalyst for the Selective Catalytic Reduction of Nox by Nh3

Abstract

To solve the severe environmental problems (such as acid rain and photochemical smog) caused by nitrogen oxides (NOx), a novel Cu-exchanged catalyst, Cu-SAPO-56, was first studied for selective catalytic reduction of NOx by ammonia (NH3-SCR). Cu-SAPO-56 exhibits excellent NH3-SCR activity and hydrothermal stability whose NOx conversion maintains more than 95% at a wide temperature range between 200 °C to 400 °C even after a rigorous steam treatment (800 °C for 16 h). There is only one kind of isolated Cu2+ ions located in double 6-ring of AFX structure, determined as the catalytic active sites. And the Cu and Si contents of Cu-SAPO-56 both play critical roles in NH3-SCR process. The excellent catalytic performance shows the huge application potential of Cu-SAPO-56 for NH3-SCR reaction.

Keywords: Cu-SAPO-56, NH3-SCR, Hydrothermal stability, Cu species, acidity