How Topological Differences between Two Oxide Surfaces Determine Selectivity—The Case of the Dehydra-Decyclization of Tetrahydrofuran

Production of butadiene from biomass-based tetrahydrofuran (THF) is explored as an alternative to the existing petroleum-based processes. Metal oxide catalysts have been shown exhibit varying product selectivities when reacted with THF. Among those oxides, ZrO2 showed highest selectivity for butadiene. In contrast, Al2O3 competing retro-Prins products, C3H6 and HCHO. The reasons behind across oxides are unclear. this work, we employ periodic density functional theory mean-field microkinetic modeling investigate mechanism reaction THF products on t-ZrO2 (101) (dry hydrous) γ-Al2O3 (110). Our simulations reproduce experimental trends. High promoted by presence neighboring Lewis acid metal sites that facilitate E1cB hydroxyl elimination a 3-butenoxide intermediate; hydrous Al2O3; where such centers not available, butenoxide undergoes E2 ensue. ring opening rate-determining ZrO2, whereas γ-proton yields intermediate rate controlling hydroxylated Al2O3. We conclude local topology around active site greatly influences selectivity.