Differences in coke burning-off from Pt-Sn/Al2O3 catalyst with oxygen or ozone

The differences in coke combustion with O3 and O2 are due to the different form of generation of activated oxygen, the species that oxidizes the coke. O3 is activated by the γ-Al2O3 support at low temperatures firstly eliminating coke from the support while O2 is activated by Pt at temperatures higher than 450 °C and the coke removal starts on the metal. Then, the recovery of the Pt catalytic activity as a function of coke elimination is faster with O2 than with O3.