Catalytic Toluene Combustion over Metastable Layered Manganese Cobalt Oxide Nanosheet Catalysts

A noble metal-free catalyst with metastable layered structures for combustion of toluene was prepared using an electrostatic self-assembly method. In this process, transition metal ions were sandwiched between negatively charged manganese cobalt oxide nanosheets with a thickness of 0.8 nm (Mn+/MnCoO, Mn+: Mn2+, Fe3+, Co2+, and Cu2+). The lowest temperature for decomposition of toluene (T-50 = 217 degrees C) was observed for Cu2+/MnCoO, which showed almost the same activity as a 0.27 wt % Ptloaded CeO2-ZrO2 catalyst. XPS and H-2-TPR spectra suggested that interlayer Cu2+ ions contributed to reducing the Mn(IV)/Mn(III) ratio and enhancing the reducibility of MnCoO nanosheets, which played an important role in improving the catalytic activity of toluene oxidation through the Mars van Krevelen mechanism. The results indicated that metastable layered structures obtained from 2D materials could open a new route for the preparation of improved noble metal-free combustion catalysts for volatile organic compounds.

Automated summary

A noble metal-free catalyst with metastable layered structures was prepared for the combustion of toluene, showing enhanced catalytic activity with Cu2+ ions contributing to the improvement in activity. The results suggested that the enhanced catalytic activity was achieved through the Mars van Krevelen mechanism, demonstrating a new route for preparing improved catalysts for volatile organic compounds.