The superior NO oxidation activity over La2CoMnO6 double perovskite to that of La2GaMnO6: effects of magnetic Co3+ and nonmagnetic Ga3+

Abstract

NO oxidation on transition metal-based perovskites has emerged as an effective strategy for reducing NO_X in automotive and industrial exhaust. Magnetic Co³⁺ and nonmagnetic Ga³⁺ cations can change the magnetic properties of double perovskites, and also affect their oxidation activity with paramagnetic O₂ and NO. Herein, La₂GaMnO₆ and La₂CoMnO₆ double perovskites with monoclinic structures were prepared via a facile molten-salt synthesis method. The coercive field (H_c), saturation magnetization (B_s), remanent magnetization (B_r), and catalytic oxidation performance of La₂CoMnO₆ were obviously larger than those of the La₂GaMnO₆ double perovskites. Thus, it was concluded, the higher the magnetic properties, the better the catalytic oxidation performance over the double perovskites.