Infrared studies of the effect of preadsorbed pyridine on the oxidation of butan-2-ol adsorbed on TiO2

Abstract

The influence of preadsorbed pyridine on the adsorption, dehydration and dehydrogenation of butan-2-ol on TiO₂ has been investigated by i.r. spectroscopy as well as by an analysis of the reaction products. Both reactions proceed via formation of butoxide species. In the presence of oxygen the major products from the butoxide are butenes, the formation of butanone being minor. The preadsorbed pyridine inhibits butene formation, while enhancing that of butan-2-one. In the absence of oxygen, only butenes are formed. On strong acid sites butanone formation is suppressed, butene formation being predominant. Adsorbed oxygen induces the production of basic sites which bring about butan-2-one formation. On weak acid sites butanone formation is the major reaction.