VIBRATIONAL INFRARED SPECTROSCOPIC STUDIES OF 1-BUTENE SKELETON ISOMERIZATION AT THE SURFACE OF A SILICATED ALUMINA IN A MICRO PLUG FLOW REACTOR

The skeletal isomerization of 1-butene to obtain 2-methylpropene is catalyzed by the interaction at high temperatures with solids having acidic properties. The nature of the solid-gas interaction is investigated through some vibrational infrared spectroscopic experiments aimed at highlighting the perturbation of the surface molecular groups and the formation of surface complexes on a silicated alumina under different conditions of pressure and temperature. The spectra recorded during the interactions lead us to propose that the catalytic isomerization occurs through a temperature-dependent proton-transfer equilibrium between an OH surface group and an H-bonded internal olefin.