High oxidation activity of thallium oxide for carbon combustion

Highlights: •Tl₂O₃ shows high carbon oxidation activity. •Combustion-related exothermic peak occurs at 300 °C for carbon black + Tl₂O₃. •However, in the absence of Tl₂O₃, it occurs at 660 °C. •Decrease in combustion temperature of carbon black is because of oxidation by Tl₂O₃. •This is because Tl₂O₃ can readily release its lattice oxygens. -- Abstract: The catalytic behavior of thallium (III) oxide (Tl₂O₃) with respect to the combustion of carbon black was investigated using thermal analysis, X-ray diffraction analysis, scanning electron microscopy, and the ¹⁸O-isotope exchange technique. The thermogravimetric-differential thermal analysis results revealed that the combustion temperature of carbon black (650 °C) decreases dramatically, to 320 °C, when it is mixed with Tl₂O₃ (2 wt% carbon black + as-purchased Tl₂O₃), owing to its oxidation by Tl₂O₃, which has the ability to readily release its lattice oxygens.