Self-regenerative function of Cu in LaMnCu0.1O3 catalyst: Towards noble metal-free intelligent perovskites for automotive exhaust gas treatment

In order to enhance the catalytic activity of LaMnO3 perovskite catalyst and induce a regenerative property under repeated reducing-oxidizing (redox) reaction conditions, a new LaMnCu0.1O3 perovskite is developed for oxidation of the simulated exhaust gas. Addition of Cu to LaMnO3 significantly enhances the specific surface area, reducibility and surface oxygen mobility of LaMnCu0.1O3, which result in the high oxidation activity of this catalyst. During the redox fluctuations using LaMnCu0.1O3, the enhancements of up to 13.4 % and 10.7 % are observed in CO and C3H8 conversions, respectively. X-ray photoelectron spectroscopy (XPS) analysis clarify that Cu reversibly reduces to Cu1+ and Cu degrees in the reducing atmosphere and re-oxidizes to Cu2+ in the oxidizing atmosphere. The activity enhancement is finally concluded to be due entirely to the formation of Cu1+ species during the reduction period. Therefore, the repeatable activity enhancement and regeneration of LaMnCu0.1O3 offer it as an intelligent and stable catalyst.