Aldol Condensation and Esterification Pathways on Bifunctional Metal-TiO2 Catalysts

Cascade reactions of C₂-C₄ oxygenates on TiO₂  and hydrogenation-dehydrogenation on metal sites lead to stable aldol condensation rates and to parallel esterification reactions, involving common enolate intermediates formed in the sole kinetically-relevant step on TiO₂.  A correlation between the reactant structure and its reactivity is unveiled both experimentally and theoretically.