On the mechanism of hydrogen-promoted gold-catalyzed CO oxidation

E. Quinet (1) , L. Piccolo (1) , F. Morfin (1) , Priscilla Avenier , F. Diehl , V. Caps (1) , J. L. Rousset (1)

1 IRCELYON - Institut de recherches sur la catalyse et l'environnement de Lyon

The kinetics of CO oxidation, H-2 oxidation and preferential CO oxidation (PrOx) over Au/Al2O3 catalysts have been investigated. The catalysts with the smallest particles (similar to 2 nm) are the most active for all three reactions. As previously observed, the presence of H-2 greatly promotes CO oxidation, which becomes faster than CO-free H-2 oxidation at low temperature. From these results and on the basis of previous works, we propose a complete PrOx mechanism. The reaction involves Au-OOH, Au-OH and Au-H intermediates, also involved in H-2 oxidation, and benefits from the presence of low-coordination sites. (c) 2009 Elsevier Inc. All rights reserved.

Domaines: Catalyse

E. Quinet, L. Piccolo, F. Morfin, Priscilla Avenier, F. Diehl, et al.. On the mechanism of hydrogen-promoted gold-catalyzed CO oxidation. Journal of Catalysis, 2009, 268 (2), pp.384-389. ⟨10.1016/j.jcat.2009.09.019⟩. ⟨hal-00463195⟩