title: Oxidation of bioethanol using zeolite-encapsulated gold nanoparticles.
abstract: With the ongoing developments in biomass conversion, the oxidation of bioethanol to acetaldehyde may become a favorable and green alternative to the preparation from ethylene. Here, a simple and effective method to encapsulate gold nanoparticles in zeolite silicalite-1 is reported and their high activity and selectivity for the catalytic gas-phase oxidation of ethanol are demonstrated. The zeolites are modified by a recrystallization process, which creates intraparticle voids and mesopores that facilitate the formation of small and disperse nanoparticles upon simple impregnation. The individual zeolite crystals comprise a broad range of mesopores and contain up to several hundred gold nanoparticles with a diameter of 2-3 nm that are distributed inside the zeolites rather than on the outer surface. The encapsulated nanoparticles have good stability and result in 50 % conversion of ethanol with 98 % selectivity toward acetaldehyde at 200 °C, which (under the given reaction conditions) corresponds to 606 mol acetaldehyde/mol Au hour(-1) .
authors.affiliation: Department of Chemistry, Technical University of Denmark, Kgs. Lyngby (Denmark).
authors.forename: Jerrik
authors.initials: J
authors.lastname: Mielby
authors.forename: Jacob Oskar
authors.initials: JO
authors.lastname: Abildstrøm
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kasama
authors.forename: Claudia
authors.initials: C
authors.lastname: Weidenthaler
authors.forename: Søren
authors.initials: S
authors.lastname: Kegnaes
mesh_terms: D000079:Acetaldehyde / Q000737:chemistry; D056804:Biofuels / Q000032:analysis; D002384:Catalysis; D000431:Ethanol / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D017641:Zeolites / Q000737:chemistry*
chemical_list: D056804:Biofuels; D017641:Zeolites; D000431:Ethanol; D006046:Gold; D000079:Acetaldehyde
keywords: acetaldehyde; bioethanol; catalytic oxidation; gold nanoparticles; zeolite