The effect of supports on coke deposition on supported platinum and platinum-tin catalysts investigated by FT-IR spectroscopy

Coke deposit is produced from ethylene on the surface of the platinum and platinum-tin catalysts supported on two various Al₂ O₃, SiO₂ and SiO₂ -Al₂O_3. The coke amount and the structure depend on the type and the amount of the components introduced onto the catalyst support and on the type of the support. It has been found that the surface area of the support has no significant effect on the type of species in the coke deposit. The analysis of the FT-IR spectra has shown the presence of different species on the surface of the catalysts, including carboxyl groups, pseudo-graphite (polyaromatic) structures, polyphenylene groups, acetyl groups, carbonyl groups of acetone and formate type, enol species.