Rhenium-promoter-free ruthenium–zirconia catalyst for high-yield direct conversion of succinic acid to 1,4-butanediol in water

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 498; p. 155603
• Main Authors: Karanwal, Neha, Gilang Kurniawan, Rizky, Kyu Kwak, Sang, Kim, Jaehoon
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.10.2024
• Subjects: 4-butanediol; Direct conversion; Oxygen vacancy; Succinic acid; Water participation; ZrOx; 1; Ru; 4-butanediol; Succinic acid; ZrOx; Water participation; Direct conversion; Oxygen vacancy
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.155603

[Display omitted] •Direct conversion of succinic acid to 1,4-butanediol (1,4-BDO) in water was studied.•Over Ru deposited on oxygen-vacant zirconia, high yield 1,4-BDO (90%) was resulted.•Zrδ+ center adjacent to the Ov sites activated the γ-butyrolactone ring-opening reaction.•Participation of H in water molecules occurred by hydrogen-shuttling mechanism.•The catalyst was active until six run and coke formation was negligible. The direct conversion of succinic acid to 1,4-butanediol (1,4-BDO) in water was investigated using Ru deposited on oxygen-vacant zirconia (Ru–OvZrOx) as the catalyst. 1,4-BDO was produced in high yield (89.5 %) and space–time yield (0.19 h−1) at 200 °C. The proximity of Ru to OvZrOx stabilized the nanosized Ru0 particles, enabled hydrogen spillover, increased the acidity of the catalyst, and achieved intermediate adsorption. The Zrδ+ center (2 ≤ δ < 4)—which featured abundant Lewis acid sites and was adjacent to the Ov sites—activated the γ-butyrolactone ring-opening reaction via a route involving 2-hydroxytetrahydrofuran formation. The electron-rich Ru0 center facilitated heterolytic hydrogen dissociation, and the dissociated H– and H+ ions traveled to the Zrδ+ sites and water molecules via hydrogen-shuttling mechanism. Moreover, the weakly bonded hydrogen actively participated in the hydrodeoxygenation and hydrogenation of intermediates to 1,4-BDO.