(127d) Effects of Lewis Acid Strength on Methanol Dehydration in Microporous Solid Acids

Alcohol dehydration, a promising route to upgrade sustainably produced oxygenates to fuels and chemicals precursors, is catalyzed by solid acids. Metal oxides such as Al₂O₃ or TiO₂ can expose different facets, and their surfaces are composed of metal centers with varied coordination environments and connectivities. Such complexities result in challenges in the unambiguous determination of active sites and their effects on reactivity and selectivity. Heteroatom-substituted zeotypes of the same framework (BEA), containing group IV or V metal atoms (M = Ti, Zr, Hf, Nb, Ta), are solid acids containing Lewis acid metal centers in similar chemical and confining environments. In this work, we use a combined experimental and computational approach to examine methanol dehydration in M-BEA. Lewis acid strength effects on reaction rates, rate constants, and free energy barriers are examined, and computational and experimental descriptors of Lewis acid strength are compared.