Heterointerface engineering regulating the energy-level configuration of α-MnO2/δ-MnO2 for enhancing toluene catalytic combustion performance

This work offers a novel approach to prepare manganese oxides with heterointerface structure as a superior catalyst for the catalytic combustion of Volatile Organic Compounds (VOCs). The α-MnO2/δ-MnO2 with heterointerfaces were prepared via annealing δ-MnO2 precursors which were obtained from the redox precipitation between HCl and KMnO4. The characterization results indicate that the heterointerface structure of α-MnO2/δ-MnO2 optimizes energy level structure and provides abundant surface defects, showing superior low-temperature reducibility and preferable mobility of oxygen species. Such features significantly enhance the catalytic activity of the α-MnO2/δ-MnO2 with heterointerfaces catalysts for the complete oxidation of toluene (the toluene conversion rates of 10 % and 90 % are 191 °C and 213 °C, respectively). Moreover, the catalysts show high stability for 50 h. The presented catalysts disclose an avenue to address current obstacles in the catalytic oxidation of VOCs.