The catalytic combustion of methane with transition metal oxides is becoming increasingly key to coping with the large emissions of lean methane from coal mine, although the reactivity of transition metal oxides at low temperature hinders its broad application. Herein, low temperature reactivities of transition metal (Cr, Mn, Fe, Co, Ni, and Cu) oxides supported on open cell foams for methane/air mixture (1 vol.% of CH₄) combustion in a fixed bed reactor were tested, and the catalysts were characterized by SEM-EDS, XRD, XPS, H₂-TPR and O₂-TPD. Results showed that the catalysts on open cell foam exhibited exceptional catalytic reactivity and thermal stability. The reactivity of them determined by the light-off ability in descending order is NiO, Fe₂O₃,  Co₃O₄, Mn₂O₃, CuO and Cr₂O₃. The light-off temperature corresponding to  the methane complete conversion for NiO was about 500 ºC, which was about 200 ºC lower than Cr₂O₃. The highest catalytic activity of the NiO catalyst was related to the largest amount of O₂ adsorption promoted by the open cell foam. This work provides a promising mean to develop more active transition metal oxides catalysts for the combustion of lean methane.
 

lean methane,Catalytic combustion,Transition metal oxides,Reactivity,Thermal stability,Low temperature