Deactivation and Regeneration of Hydrogenolysis Activity over Rh-Ag Bimetallic Catalysts Supported on TiO sub 2

摘要

An indirect effect of support on the kind of bimetallic interaction was observed on Rh-Ag catalysts supported on TiO sub 2 compared to SiO sub 2 . This effect occurs at significantly lower temperatures than the direct Strong Metal-Support Interaction (SMSI) between Rh and TiO sub 2 . The main feature of this indirect effect is a pronounced decay in the H sub 2 chemisorption capability and activity for ethane hydrogenolysis with time when the catalysts are left in flowing H sub 2 at 523K. This behavior can be rationalized in terms of a modification of the energetics of the metal-metal interaction, which may cause the Ag to spread over Rh particles. Hydrogenolysis activity and H sub 2 chemisorption capacity can be regenerated by an oxidation-reduction treatment. (ERA citation 08:018333)