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 aluminum 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.