365 / 2024-03-22 11:13:16

Catalytic performance of transition metal (Cr, Mn, Fe, Co, Ni, Cu and Zn) oxides on open cell foams for lean methane combustion

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

5、智慧能源与清洁电力技术 > 10、清洁能源转换及减排技术

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, Cu and Zn) 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, CH₄-TPD and O₂-TPO. 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 Co₃O₄, Mn₂O₃, Cr₂O₃, CuO, Fe₂O₃ NiO and ZnO. The light-off temperature corresponding to 10% of the methane conversion (T₁₀) for Co₃O₄ was about 256 ºC, which was about 200 ºC lower than ZnO. Moreover, the 90% of methane conversion temperature (T₉₀) for Co₃O₄ catalyst was about 427 ºC, closing to the reactivity of Pd-based catalysts (T₉₀≈375 ºC). The highest catalytic activity of the Co₃O₄ 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.