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

Abstract BACKGROUND Core–shell structure Mn 2 O 3 @MnO 2 (MnO x ) has been prepared using KMnO 4 modifying spherical Mn 2 O 3 assembled by nanoparticles, and applied for catalytic toluene oxidation. RESULTS The MnO x sample calcined at 350 °C (MnO x ‐1) exhibited much higher catalytic activity compared with Mn 2 O 3 and MnO x ‐2 (calcined at 450 °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 MnO x ‐1. CONCLUSIONS The excellent activity of the MnO x ‐1 catalyst can be attributed to the more surface Mn 4+ and many surface lattice oxygen species derived from the special core–shell structure, improving the oxidation of toluene. © 2021 Society of Chemical Industry (SCI).