The improved reactivity of manganese catalysts by Ag in catalytic oxidation of toluene

► Ag/Mn ratio of 1:3 is an appropriate ratio for high activity for toluene oxidation. ► Ag enters into MnO2 phase and leads the formation of Ag1.8Mn8O16 and Mn2O3. ► The ratios of Mn3+/Mn4+and Olatt/Osurf on the Mn catalyst are increased by Ag. ► The oxygen mobility and reducibility of manganese oxides are enhanced by Ag. ► The formation of benzaldehyde is closely related with lattice oxygen of the catalyst.