Activity and stability of cobalt-manganese catalysts in the process of methane flameless combustion

Oxide cobalt-manganese catalysts with different contents of cobalt and manganese, as well as pure cobalt and manganese catalysts have been tested in the process of methane flameless combustion (complete catalytic oxidation). The X-ray diffraction and X-ray photoelectron spectroscopy results showed that cobalt-manganese catalysts mainly composed of the spinel phase of Co$\text{}_{3}$O$\text{}_{4}$, Mn$\text{}_{2}$CoO$\text{}_{4}$ and/orMnCo$\text{}_{2}$O$\text{}_{4}$. The highest initial activity was presented bythe cobalt-manganese catalyst withahigh cobalt content.However, after 50-hours stability test the highest activity was presented by the cobalt-manganese catalyst with Co and Mn content close to the equimolar value.