Toluene oxidation over defected Mn-based catalyst with controlled Mn-O strength derived from LaMnO3 perovskite.

Mn-based heterostructure catalysts show great potential for catalytic oxidation of toluene. Here we fabricated a Mn-based catalyst with controlled Mn–O strength from a LaMnO 3 perovskite parent, the surficial structure of which was optimized via defect engineering by joint modification of Ce substitution and acid etching. The findings displayed that after introduction of Ce, a Mn 3 O 4 /Ce 6 O 11 hybrid was in situ formed inside LaMnO 3 structure owing to the incompatibility of Ce atoms, and the etching of acid resulted in the exposure of Mn 3 O 4 /Ce 6 O 11 hybrid by exfoliating the surficial structure. The reconstruction of catalyst structure and dismutation of Mn species was conductive to forming more lattice defects and Mn– O –Ce active sites, thereby harmonizing Mn–O strength. Furthermore, the fabricated catalyst exhibited a suitable Mn2+/Mn4+ ratio and more oxygen vacancies, which inferred easy-release of lattice oxygen and improved oxygen adsorption-activation capacity, therefore synergistically contributed to the highest performance (T 90 = 259 °C) of toluene oxidation. [Display omitted] [ABSTRACT FROM AUTHOR]