Catalytic Oxidation of Carbon Monoxide by Cobalt Oxide Catalysts Supported on Oxidized-MWCNT

Cobalt oxide catalysts supported on oxidized multi-walled carbon nanotubes (MWCNT) for the low-temperature catalytic oxidation of carbon monoxide were prepared by an impregnation-ultrasound method. These catalysts were characterized by N2 adsorption/desorption, TEM, XRD, Raman, and H2-TPR methods. The XRD and Raman results indicated that the phase of the synthesized cobalt oxide was in the Co3O4 form. The effects of cobalt oxide loading and reaction temperature were studied on the catalytic oxidation conversion of carbon monoxide. The TEM image of the best catalyst (14 wt.% metal oxide loading) revealed a good dispersion of Co3O4 over the surface of the support with an average particle size of 11-16 nm. Under the reaction conditions of T= 200-250 °C, P=1 bar, CO = 600 ppm, O2 = 5 vol.%, GHSV = 30,000 hr.−1, and Co3O4= 14 wt.%, CO conversion was 91%.