Reactivity of Ethyl Groups on a Sn/Pt(111) Surface Alloy.

In order to probe the thermal stability and reactivity of ethyl intermediates on Pt-Sn alloy catalysts, we have synthesized these species by reaction of H atoms with adsorbed ethylene on a () R30°-Sn/Pt(111) surface alloy. Adsorbed ethyl groups are stable until 376 are they react to evolve ethane, ethylene, and H2. The activation energy for ethyl dehydrogenation isEdehyd* 97 kJ mol, which istwicethat reported on Pt(111). In addition, we place a lower limit ofEdehyd* 97 kJ mol on the barrier to ethyl hydrogenation on this alloy. [ABSTRACT FROM AUTHOR]