Ethylene Oxidation in an Oxygen‐Deficient Environment: Why Ceria is an Active Support?

Abstract

Abstract Pt/CeO 2 , Ru/CeO 2 , Ir/CeO 2 and the corresponding unsupported nanoparticles (Pt, Ru and Ir) were evaluated for their performance in the complete oxidation of ethylene in the presence and absence of oxygen. The lattice oxygen and oxygen storage capacity (OSC) of CeO 2 had a significant influence on the interaction with the supported metal nanoparticles, which caused different catalytic behaviours in the absence of oxygen. Overall, Ru/CeO 2 was more stable than Ir/CeO 2 and Pt/CeO 2 , which results in transient promotional rate enhancement ratio ( ρ MSI ; MSI=metal–support interaction) values that reach 200 in the first 25 min. These results were attributed to the corresponding interaction with CeO 2 and negligible carbon deposition. A proposed relationship between ρ MSI and the O 2− consumed from CeO 2 is discussed, which was suggested as a possible tool to estimate the extent of the MSI. In general, an increase in ρ MSI corresponded to an increase in O 2− consumed from ceria.