Performance of the supported copper oxide catalysts for the catalytic incineration of aromatic hydrocarbons

A fixed bed reactor was used to assess the catalytic incineration of toluene by various transition-metal oxide species supported on γ-Al2O3. CuO/γ-Al2O3 was found to be the most active of seven catalysts investigated. The CuO species, with a Cu content of 5% (wt), was hence used with four different supports (CeO2, γ-Al2O3, TiO2 and V2O5) in order to define the optimal combination. Results of the catalytic incineration of toluene, X-ray diffraction (XRD) analysis, oxygen-temperature programmed desorption (O2-TPD), toluene-temperature programmed desorption (toluene-TPD) and hydrogen-temperature programmed reduction (H2-TPR) showed that CuO/CeO2 was the most active catalyst, followed by CuO/γ-Al2O3. The activity of CuO/CeO2 with respect to the VOC molecule was observed to follow this sequence: toluen > p-xylene > benzene. The addition of water vapor or CO2 significantly inhibited the activity of the CuO/CeO2 and CuO/γ-Al2O3 catalysts. The inhibiting effect of both was reversible for CuO/γ-Al2O3. For CuO/CeO2, the inhibiting effect of CO2 was reversible and even insignificant at a higher temperature (220 °C), but the effect of H2O vapor was somewhat irreversible at lower incineration temperatures (less-than-or-equals, slant220 °C). For complete oxidation of toluene, the required reaction temperature increased with gas hourly space velocity (GHSV) and toluene inlet concentration.