Combustion of carbon black catalyzed by transition metal-promoted Y2O3-CeO2-ZrO2 solid solutions

The activity of M-free and M-loaded 10YO(1.5)-10CeO(2)-80ZrO(2) solid solution (M = Cu, V, or W) towards carbon black combustion was studied using TG/DTA and TPO techniques. It was demonstrated that all studied catalysts lower the temperature of carbon black combustion. The selectivity of the catalytic reaction in CO, formation was 100%. It was evidenced that the fast oxidation of carbon at lower temperatures, observed only in the TG/DTA apparatus, was due to heat- and mass-transfer limitations, resulting in a runaway reaction. Using TPR technique, it was shown that, in the temperature range of DTA curve, oxygen on the catalyst surface was rather reactive (and, therefore, it could be easily released by support for the oxidation of carbon), whereas the reactivity of bulk oxygen was negligible. The activity of the metal-loaded 10YO(1.5)-10CeO(2)-80ZrO(2) (Y-10) samples varied according to the following sequence: Cu/Y-10 > V/Y-10 > W/Y-10. For Cu- and V-containing catalysts, a contribution of a surface redox mechanism in reaction was proposed by comparing EPR spectra of pure catalysts with those of the samples (catalysts mixed with carbon black) after catalysis.