abstracts - Институт катализа им. Г.К. Борескова

OP-I-15After performing an ageing test in carbon black oxidation, the catalysts showed arelatively long life and could be reused for various catalytic cycles (8 to 10 cycles) withoutdeactivation. After each cycle, catalysts were studied by temperature programmed reduction(TPR) and the apparition of new reduction peaks was observed. These new reduction peaksindicated the presence of new Ru specie that reduce at higher temperatures which can becorrelated with the deactivation of the catalysts.Several techniques were used to evaluate physico-chemical properties of the solids. It wasshown that after calcination at 600 °C the ruthenium is present as RuO 2 oxide on ceria’ssurface. TPR experiments of the catalysts showed that the oxygen species of RuO 2 wasreduced at low temperatures. In addition, Electronic Paramagnetic Resonance (EPR)studies ofoutgassed samples at different temperatures showed an anisotropic signal indicating thatRu(IV) was reduced to intermediate valences states like Ru(III) and Ru(II) at lowtemperatures.It is concluded that “Ru-O-Ce” bonds in the well dispersed Ru species are highly fragileand that good oxidation activity is related to its mobile oxygen.References:[1] J.P.A. Neeft, O.P. vanPruissen, M. Makkee and J.A. Moulijn, Applied Catalysis B:Environmental, Volume 12, (1997), p. 21.[2] S. Hosokawa, H. Kanai, K. Utani, Y. Taniguchi, Y. Saito and S. Imamura, AppliedCatalysis B: Environmental, Volume 45, Issue 3, (2003), p. 181.[3] S. Hosokawa, Y. Fujinami and H. Kanai, Journal of Molecular Catalysis A: Chemical,Volume 240, Issues 1-2, (2005), p. 49107