Low-Temperature O₃-Catalytic Oxidation of Methane on Cobalt-Containing Zeolite Catalysts

The Co/BEA zeolite catalyst was found to exhibit exceptionally high activity in ozone catalytic oxidation (OZCO) of methane impurities in air, and it provided CH₄ conversion >85% in the temperature range 90–170°С at a high gas hourly space velocity (100 000 h^–1). A comparative study of the catalytic performance of 0.5% Co/BEA, 5% Co/BEA, and 5% Co/SiO₂ samples was performed for elucidating the nature of the active sites on which the process takes place. The comparison of the catalytic data with the results of catalyst characterization by electron microscopy, UV spectroscopy, X-ray diffraction analysis, and temperature-programmed reduction allowed us to conclude that the active sites of low-temperature methane oxidation are Co²⁺ ions located in the cationic positions of the zeolite framework, and the 0.5% Co/BEA catalyst had the highest activity in methane oxidation.