Surface Structure and Temperature Dependence of Light-Alkane Skeletal Rearrangement Reactions Catalyzed over Platinum Single-Crystal Surfaces

Article abstract of DOI:10.1021/ja00390a011

The structure sensitivity of isobutane, n-butane, and neopentane hydrogenolysis and isomerization catalyzed over a series of flat, stepped, and kinked platinum single-crystal surfaces was investigated near atmospheric pressure and 540-640 K.The atomic structure and surface composition of the active catalyst were determined before and after reaction studies by using low-energy electron diffraction and Auger electron spectroscopy.Catalytic activities for butane isomerization and consecutive rearrangement reactions were maximized on platinum surfaces with high concentrations of (100) microfacets.Maximum rates for the competing hydrogenolysis reactions were obtained on platinum surfaces that contain high concentrations of steps and kinks.Hydrogenolysis product distributions varied markedly with terrace structure.The symmetries of d orbitals that emerge from the surfaces with different atomic structure have been used to rationalize the structure sensitivity of light-alkane isomerization.