Perovskite-type oxides as catalysts for selective reduction of nitric oxide by ethylene

The selective catalytic reduction of NO with C2H4 (C2H4-SCR) was investigated over perovskites containing Co, Mn, Fe, Cr, Al, Sn and Ti as host B-site cations. The C2H4-SCR activity was observed over Al-, Sn- and Ti-based oxides which were free from redox-active metal cations such as Co and Cu and innately poor in oxidation activity. Over perovskites containing redox-active metal cations, the undesirable consumption of C2H4 by O2 proceeded preferentially.