Catalytic Combustion of Lean Methane-Air Mixture over Electrochemically Obtained Copper Oxides

Electrochemical oxidation of copper was investigated as a method for producing catalytically active copper oxides for methane oxidation. The catalytic activity of the obtained materials was evaluated in the oxidation of methane in air containing 0.45 vol% CH₄. The activity was assessed using the T ₅₀ parameter, defined as the temperature at which 50% methane conversion is achieved. For a gas flow of 200 mL min^-1 in a Berty-type gradientless reactor, the T ₅₀ values obtained for catalysts prepared by Methods 1, 2, and 3 were 474, 473, and 549 °C, respectively. The results indicate a higher activity of the electrochemically produced oxides compared with commercial CuO. The physicochemical properties of the catalysts were characterized using scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis (TGA).