Chiang Mai Journal of Science

Ventilation air methane is released into the atmosphere by most coal mines owing to the low methane content, which not only causes a waste of resources but also results in irreparable damage to the environment. To clarify the catalytic mechanism of methane on perovskite-type oxide catalysts, density functional theory was used to study the adsorption behavior of CH₄ and O₂ molecules on the surface of LaCoO₃ (001). Three and two possible adsorption configurations for CH₄ and O₂ molecules were found in the present work. The most stable adsorption configurations and Bader charges analysis show that the best adsorption site for methane and oxygen on the LaCoO₃ (001) surface are both the top position of Co. It is well known that gas adsorption is an important step in the combustion process. In this work, we find that LaCoO₃ shows higher adsorption energy for the two molecules compared with precious metal catalysts. It is, therefore, reasonable to deduce that LaCoO₃ is a methane combustion catalyst with excellent catalytic performance, which will lay a solid theoretical foundation for the study of the catalytic mechanism of perovskite-type oxide catalysts.