Oxidation characteristics of Ru/CeO2 catalyst

Oxidation characteristics of Ru/CeO2 were investigated by N2O decomposition in the presence of C3H6, by temperature programmed desorption (TPD), IR, and XAFS measurements using C3H6 as a probe molecule. Ru/CeO2 (Ru: 5 wt%) had highly dispersed Ru species which formed RuOCe and RuO bonds. This Ru species was in the five-coordination environment and reacted rapidly with allylic hydrogen of C3H6, providing its double bond oxygen. The RuO site was easily regenerated under oxygen atmosphere. This type of metal-oxo species was not formed for Pt, Pd, and Rh on CeO2. The peculiar oxidation property of Ru/CeO2 catalyst was due to the RuO species. The optimal preparation procedure for producing RuO species was to support Ru on hydrated Ce(OH)3 without drying or calcinations. The saturated amount of RuO species was 2 wt% loading of Ru.