In situ XAFS study of the thioresistance of metallic Ru supported on HYd zeolite
Résumé
In situ XAFS at the Ru K edge was used to investigate the reduction of Ru(NH3)63+ supported on HYd zeolite, and the evolution of the reduced sample in the presence of sulfur (350 ppm and 2%H2S/H2) at 523K. After reduction at 673K very small Ru° nanoparticules are formed which interact strongly with the zeolite framework. In the presence of sulfur, the evolution with time of the FT of the XAFS signal shows the formation of an increasing amount of Ru-S bonds. Nevertheless even after 3h under 2%H2S/H2 the number of Ru-S bonds remains low (N(S)=1.3) by comparison with other metals and the number of Ru-Ru bonds remains unchanged.