Infrared studies of acid–base properties of vanadium–titanium oxide and oxidation of alcohols on it

Abstract

The adsorption of pyridine and pyrrole and the oxidation of alcohols has been studied on V–Ti oxide by infrared spectroscopy. V–Ti oxide has both Brönsted- and Lewis-acid sites as well as strong basic sites. The V–Ti oxide exhibits a high activity for the dehydrogenation of propan-2-ol to acetone, which proceeds via the formation of alkoxide species. The dehydrogenation reaction is markedly suppressed by the adsorption of pyridine and pyrrole, suggesting that Lewis-acid and base sites play a significant role in the dehydrogenation. Vanadium ions and oxygen in the surface VO species on V–Ti oxide constitute the Lewis-acid and base sites, respectively. The former are the chemisorption sites for alkoxide formation and the latter abstract hydrogen from the alkoxide.