Tin oxide surfaces. Part 14.—Infrared study of the adsorption of ethane and ethene on tin(IV) oxide, tin(IV) oxide–silica and tin(IV) oxide–palladium oxide

Abstract

The adsorption of ethane and ethene onto tin(IV) oxide, tin(IV) oxide–silica, and tin(IV) oxide–palladium oxide at various pretreatment temperatures in the range 320–740 K has been studied by transmission infrared spectroscopy. In every case the ultimate surface product was a surface acetate, except in the case of ethane and tin(IV) oxide, where no evidence for adsorption could be obtained under any conditions. The proposed mechanism for the formation of acetate involves the oxidation of an initially formed surface ethoxide species, although this intermediate is thought to arise via dissociative chemisorption, with C—H bond fission in the case of ethane and an electrophilic addition of surface hydroxyl groups across the CC double bond in the case of ethene. Decomposition of the surface acetate to a surface carbonate occurs at temperatures > 580 K.