Excellent oxidation activity of toluene over core-shell structure Mn2O3@MnO2: role of surface lattice oxygen and Mn species

BACKGROUND Core-shell structure Mn2O3@MnO2 (MnOx) has been prepared using KMnO4 modifying spherical Mn2O3 assembled by nanoparticles, and applied for catalytic toluene oxidation. RESULTS The MnOx sample calcined at 350 degrees C (MnOx-1) exhibited much higher catalytic activity compared with Mn2O3 and MnOx-2 (calcined at 450 degrees C), good activity stability with recyclability. Bulk structure, redox ability and surface properties were characterized using various techniques. The relationship between the catalytic activity and the surface Mn and oxygen species of these catalysts is discussed in terms of these characterizations. Especially, in situ diffuse reflectance infrared Fourier transform spectroscopic measurements were used to analyze in detail the role of the surface lattice oxygen in the enhanced catalytic performance of MnOx-1. CONCLUSIONS The excellent activity of the MnOx-1 catalyst can be attributed to the more surface Mn4+ and many surface lattice oxygen species derived from the special core-shell structure, improving the oxidation of toluene. (c) 2021 Society of Chemical Industry (SCI).