On the intermediates of the acetic acid reactions on oxides: an IR study

Adsorption of acetic acids has been studied by FT-IR on a series of adsorbents, known as good catalysts for the selective hydrogenation of carboxylic acids to corresponding aldehydes: SnO2, TiO2, PtSnO2, PtTiO2. Very similar adsorbed species are observed by FT-IR with all mentioned catalysts. The catalysts differ mainly by their behaviour upon increasing temperature program. The strongly bound unidentate or the bidentate, bound to the oxide, are the possible intermediates of the catalytic reaction to acetaldehyde.