title: Insights into the Ring-Opening of Biomass-Derived Furanics over Carbon-Supported Ruthenium.
abstract: The selective ring-opening of cellulose-derived furanic molecules is a promising pathway for the production of industrially relevant linear oxygenates, such as 1,6-hexanediol. 2,5-Dimethylfuran (DMF) is employed as a model compound in a combined experimental and computational investigation to provide insights into the metal-catalyzed ring-opening. Ring-opening to 2-hexanol and 2-hexanone and ring-saturation to 2,5-dimethyltetrahydrofuran (DMTHF) are identified as two main parallel pathways. DFT calculations and microkinetic modeling indicate that DMF adsorbs on Ru in an open-ring configuration, which is potentially a common surface intermediate that leads to both ring-opening and ring-saturation products. Although the activation barriers for the two pathways are comparable, the formation of DMTHF is more thermodynamically favorable. In addition, steric interactions with co-adsorbed 2-propoxyl, derived from the solvent, and the oxophilic nature of Ru play key roles to determine the product distribution: the former favors less bulky, that is, ring-closed, intermediates, and the latter retards O-H bond formation. Finally, we show that the hydrodeoxygenation of oxygenated furanics, such as 5-methylfurfural and (5-methyl-2-furyl)methanol, on Ru occurs preferentially at oxygen-containing side groups to form DMF, followed by either ring-opening or ring-saturation.
authors.affiliation: Catalysis Center for Energy Innovation, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, 19716, United States.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Gilkey
authors.affiliation: Catalysis Center for Energy Innovation, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, 19716, United States.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Mironenko
authors.affiliation: Catalysis Center for Energy Innovation, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, 19716, United States.
authors.forename: Leerang
authors.initials: L
authors.lastname: Yang
authors.affiliation: Catalysis Center for Energy Innovation, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, 19716, United States.
authors.forename: Dionisios G
authors.initials: DG
authors.lastname: Vlachos
authors.affiliation: Catalysis Center for Energy Innovation, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, 19716, United States.
authors.forename: Bingjun
authors.identifier: http://orcid.org/0000-0002-2303-257X
authors.initials: B
authors.lastname: Xu
mesh_terms: D018533:Biomass; D002244:Carbon; D002384:Catalysis; D005663:Furans / Q000737:chemistry*; D055601:Organic Chemistry Phenomena; D012428:Ruthenium
chemical_list: D005663:Furans; D002244:Carbon; D012428:Ruthenium; C039281:furan
keywords: biomass; hydrogenation; reaction mechanisms; ruthenium; supported catalysts