Oxidation of CO on the Cu–Co–Fe oxide system applied on carbon nanotubes synthesized on Co2O3

Resumo

Physicochemical characteristics of carbon nanotubes synthesized on Co₂O₃ and oxide Cu–Co–Fe catalysts on their base applied in the CO oxidation reaction have been investigated. It is shown that the deposition technology of the active mass, which, according to the X-ray phase analysis, is a mixture of the Cu₂(OH)₃NO₃ and CuO phases, strongly influences the activity of the Cu–Co–Fe/CNT catalysts. The greatest amount of the Cu₂(OH)₃NO₃ phase is observed in the catalysts produced by a single deposition of the active component on carbon nanotubes, which according to the thermodesorption mass spectroscopy, contributes to the formation of active centers with the lower activation energy of the CO₂ desorption and the reaction of the CO oxidation proceeds at a considerably lower temperatures. The TEMdata indicate that at the step-by-step deposition of the active mass in the surface layer the formation of the massive agglomerates, which are inhomogeneously located on the disordered structures of nanotubes, and this unfavourably affects the catalytic properties of Cu–Co–Fe/CNT catalysts.