title: A continuous flow strategy for the coupled transfer hydrogenation and etherification of 5-(hydroxymethyl)furfural using Lewis acid zeolites.
abstract: Hf-, Zr- and Sn-Beta zeolites effectively catalyze the coupled transfer hydrogenation and etherification of 5-(hydroxymethyl)furfural with primary and secondary alcohols into 2,5-bis(alkoxymethyl)furans, thus making it possible to generate renewable fuel additives without the use of external hydrogen sources or precious metals. Continuous flow experiments reveal nonuniform changes in the relative deactivation rates of the transfer hydrogenation and etherification reactions, which impact the observed product distribution over time. We found that the catalysts undergo a drastic deactivation for the etherification step while maintaining catalytic activity for the transfer hydrogenation step. (119) Sn and (29) Si magic angle spinning (MAS) NMR studies show that this deactivation can be attributed to changes in the local environment of the metal sites. Additional insights were gained by studying effects of various alcohols and water concentration on the catalytic reactivity.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA) http://www.romangroup.mit.edu.
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Lewis
authors.forename: Stijn
authors.initials: S
authors.lastname: Van de Vyver
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Crisci
authors.forename: William R
authors.initials: WR
authors.lastname: Gunther
authors.forename: Vladimir K
authors.initials: VK
authors.lastname: Michaelis
authors.forename: Robert G
authors.initials: RG
authors.lastname: Griffin
authors.forename: Yuriy
authors.initials: Y
authors.lastname: Román-Leshkov
mesh_terms: D000440:Butanols / Q000737:chemistry; D002384:Catalysis; D004987:Ethers / Q000737:chemistry*; D005662:Furaldehyde / Q000031:analogs & derivatives* / Q000737:chemistry; D006865:Hydrogenation; D058116:Lewis Acids / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D017641:Zeolites / Q000737:chemistry*
chemical_list: D000440:Butanols; D004987:Ethers; D058116:Lewis Acids; D014867:Water; C043958:2-butanol; D017641:Zeolites; C008046:5-hydroxymethylfurfural; D005662:Furaldehyde
keywords: biomass conversion; cascade reactions; hydrogen transfer; solid lewis acids; zeolites