Comment on "towards understanding the bifunctional hydrodeoxygenation and aqueous phase reforming of glycerol" [J. Catal. 269 (2010) 411-420]

A recent experimental study of 1- and 2-propanol in water feed over Pt/Al₂O₃ yielded dehydrogenation of 2-propanol to acetone, but formation of CO₂ and ethane from 1-propanol. To rationalize this reactivity difference of primary and secondary alcohols, we explored computationally the dehydrogenation of 1- and 2-propanol over Pt(111) as model. As product of 2-propanol, our calculations confirm acetone which adsorbs only weakly; thus, desorption occurs readily as the subsequent dehydrogenation would exhibit a high barrier. For 1-propanol we determined propionyl as strongly adsorbed intermediate which eventually undergoes C-C bond breaking.