Hydrogenolysis and isomerization of n-butane on low-index Pt single crystals and polycrystalline Pt foil

Article abstract of DOI:10.1006/jcat.1996.0060

The hydrogenolysis and isomerization of n-butane over Pt(100) and Pt(111) single crystals and a poly crystalline Pt foil have been studied over a wide range of reaction temperatures (510-610 K) and hydrogen partial pressures (7.5-250 Torr). The activity and selectivity have both been determined as a function of temperature and hydrogen partial pressure. The more open Pt(100) surface was an order of magnitude more active than the close-packed Pt(111) surface. Hydrogenolysis selectivities were invariant with reaction temperature over the range studied. Hydrogen partial pressure affected both the activity and product distribution. Both single-crystal surfaces exhibit a decrease in the activity as the H₂ pressure is decreased below a critical amount and this decrease is directly attributable to the formation of a carbonaceous surface residue. The amount of isomerization was always less than the amount of hydrogenolysis regardless of the n-butane to hydrogen ratio or the reaction temperature.