A one-pot synthesis of Cu-modified Mn-rich MnSAPO-34 catalyst with excellent low temperature NH3-selective catalytic reduction performance and H2O resistance

Abstract

A one-pot synthetic method was used to prepare copper (Cu)-modified manganese (Mn)-rich MnSAPO-34 catalysts, which were then used for NOx removal from stationary-source flue gas. The addition of Cu to these Mn-rich MnSAPO-34 catalysts significantly enhanced their low temperature (LT) selective catalytic reduction (SCR) activity and H2O resistance. The Mn0.4Cu0.05SAPO-34 catalysts demonstrated excellent LT NH3-SCR activity, with NOx removal being >90% from 160 to 300°C. In addition, Mn0.4Cu0.05SAPO-34 catalysts exhibited high H2O resistance. This excellent performance was ascribed to strong synergistic effects between Mn4+ and isolated Cu2+ species in Mn0.4Cu0.05SAPO-34 catalysts, leading to suitable redox ability. The results of in situ FT-IR analysis indicated that LT-SCR reactions mainly proceeded by an Eley–Rideal reaction pathway at 200°C in Cu-modified manganese-rich MnSAPO-34 catalysts. Thus, Mn0.4Cu0.05SAPO-34 was considered as a promising candidate for NOx removal from flue gas of stationary sources at low temperatures.