INFRARED STUDY OF CROTONALDEHYDE AND CO ADSORPTION ON A PT TIO2 CATALYST/

A Pt/TiO2 catalyst has been subjected to reduction in hydrogen at 473, 573 and 773 K and the various degrees of metal-support interaction (S MSI) confirmed by means of CO and H-2 chemisorption, FTIR of CO and th e hydrogenation of crotonaldehyde. Coadsorption of CO and crotonaldehy de were performed to identify the preferred adsorption site and mode o f adsorption of the unsaturated aldehyde. Results which appear to sugg est shifts to lower frequencies of bands due to adsorbed carbonyls are not due to electronic effects induced by coadsorption, but rather ind icate displacement of CO from the weaker bonding sites which eliminate dipole coupling effects between different carbonyl clusters, and cons equently removes intensity transfer phenomena leading to enhancement i n intensity at lower frequencies.