Effects of Calcination Temperature and Calcination Atmosphere on the Performance of Co3O4 Catalysts for the Catalytic Oxidation of Toluene

A series of Co3O4 catalysts were synthesized and derived from Co-BTC (BTC = 1,3,5-benzenetricarboxylic acid). The effects of different calcination temperatures and calcination atmospheres on the catalytic activity of the materials were investigated. The characteristics of the catalysts were investigated by using various techniques, including X-ray diffraction, N-2 adsorption-desorption measurements, scanning electron microscopy, X-ray photoelectron spectroscopy, and H-2 temperature-programmed reduction. The findings demonstrated that an increase in calcination temperature caused a higher agglomeration of grains, reduced the specific surface area, and influenced the contents of the active substance Co3+ and surface-adsorbed oxygen of the catalyst. The catalyst pretreated under the N-2 atmosphere showed a more uniform particle distribution, better low-temperature reducibility, and the highest catalytic activity. The in situ DRIFTS results indicated that toluene was decomposed successively to benzaldehyde, benzoic acid, bicarbonate, and carbonate species and was eventually broken down into small molecules of CO2 and H2O as the temperature increased.