Effects of Copper Sources on the Performance of Cu-SSZ-13 Catalyst for NOx Removal

Cu-SSZ-13 catalysts with different copper sources(copper nitrate, copper sulfate and copper acetate) were prepared by ion exchange method. Effects of the copper sources in Cu-SSZ-13 catalysts on the reaction activity of selective catalytic reduction(SCR) were investigated. Physicochemical properties of the samples were characterized by X-ray diffraction(XRD), Brunauer, Emmett and Teller(BET), X-ray photoelectron spectroscopy (XPS), temperature program reduction by hydrogen(H2-TPR) and temperature programmed desorption by ammonia(NH3-TPD). The results show that the Cu-SSZ-13 catalysts have good SCR catalytic activity and N2 selectivity, and the Cu-SSZ-13 catalyst with organic copper source(copper acetate) has a good low temperature catalytic activity and NH3 adsorption stability. After hydrothermal aging, T90 reaches over 90% during the temperature range of 175-575℃. The intensity of the diffraction peak of chabazite(CHA) structure decreases slightly, but the hydrothermal aging does not damage the CHA structure of the catalysts, indicating that the catalysts after hydrothermal aging can maintain high SCR activity. After adding propylene with a volume fraction of 500×10-6 to the reaction feed at 300℃, the catalyst is not toxified and deactivated by propylene, and the NOx conversion rate maintains above 90%. © 2022, Editorial Office of the Transaction of CSICE. All right reserved.