Cobalt-Copper Oxide Catalysts for VOC Abatement: Effect of Co:Cu Ratio on Performance in Ethanol Oxidation

• Published in: Catalysts 2023-01, Vol.13 (1), p.107
• Main Authors: Kupková, Květa, Topka, Pavel, Balabánová, Jana, Koštejn, Martin, Jirátová, Květuše, Giraudon, Jean-Marc, Lamonier, Jean-Francois, Maixner, Jaroslav, Kovanda, František
• Format: Article
• Language: English
• Subjects: Air pollution; Carbon dioxide; Catalysis; Catalysts; Catalytic converters; Chemical reactions; Chemical Sciences; Cobalt oxides; cobalt-copper oxide catalysts; Conversion; Copper; Copper oxides; Cost control; Ethanol; ethanol total oxidation; Expected values; Metal oxides; Mixed oxides; Nitrates; Oxidation; Raman spectroscopy; Ratios; Reduction; Selectivity; Stainless steel; Synergistic effect; VOC abatement; VOCs; Volatile organic compounds; X ray photoelectron spectroscopy
• ISSN: 2073-4344; 2073-4344
• DOI: 10.3390/catal13010107

The effect of the Co-Cu oxide catalysts composition on their physicochemical properties and performance in the deep oxidation of ethanol was studied. The catalysts with Co:Cu molar ratios of 4:1, 1:1, and 1:4 were obtained by calcination (4 h at 500 °C in air) of the coprecipitated precursors and characterized in detail using powder XRD, Raman spectroscopy, N2 physisorption, H2-TPR, and XPS. The powder XRD and Raman spectroscopy indicated the formation of Co3O4 and CuO mixtures rather than Co-Cu mixed oxides. The CuO promoted the Co3O4 reduction; the Co-Cu catalysts were reduced more easily than the single-component Co and Cu oxides and the main reduction maxima were shifted to lower temperatures with increasing cobalt content in the catalysts. The Co-Cu oxide catalyst with a Co:Cu molar ratio of 4:1 exhibited the best performance in ethanol gas-phase oxidation, showing the lowest T50 (91 °C) and T90(CO2) (159 °C) temperatures needed for 50% ethanol conversion and 90% conversion to CO2, respectively. The excellent catalytic properties of this Co-Cu oxide catalyst were ascribed to the synergistic effect of Co and Cu components. The high activity and selectivity of the Co-Cu catalyst was attributed to the presence of finely dispersed CuO particles on the surface of Co3O4.