Structural evolution in LaCoO3 by polyol treatment: Highly active and resistant Co3O4/La2O2CO3/LaCoO3 heterostructure catalysts for CH4 oxidation

The development of high-performance nonprecious metal catalysts that are resistant to water and poisoning is of great importance for industrial methane treatment and is challenging. Herein, we prepared a Co3O4/La2O2CO3/LaCoO3 heterostructure catalyst with excellent catalytic performance (T90 =476 °C), resistance to water and resistance to poisoning using a simple solvent-thermal method. DFT calculations combined with experimental characterization demonstrated that La2O2CO3 provides more reactive oxygen species (O- and O2-) to Co3O4 via charge transfer at the interface to enhance the oxidation of methane. Moreover, water and SO2 could be preferentially adsorbed on La2O2CO3 to protect the active site of Co3O4, which improved its poisoning tolerance. Correspondingly, the structure had more density states near the Fermi level and accelerated the electron transfer on the structural surface, which enhanced the adsorption and dissociation of oxygen and methane. This research provides a comprehensive understanding of the structure-performance relationship of heterogeneous structured catalysts in catalytic combustion.