title: Spectroscopic evidence for origins of size and support effects on selectivity of Cu nanoparticle dehydrogenation catalysts.
abstract: Selective dehydrogenation catalysts that produce acetaldehyde from bio-derived ethanol can increase the efficiency of subsequent processes such as C-C coupling over metal oxides to produce 1-butanol or 1,3-butadiene or oxidation to acetic acid. Here, we use in situ X-ray absorption spectroscopy and steady state kinetics experiments to identify Cuδ+at the perimeter of supported Cu clusters as the active site for esterification and Cu0surface sites as sites for dehydrogenation. Correlation of dehydrogenation and esterification selectivities to in situ measures of Cu oxidation states show that this relationship holds for Cu clusters over a wide-range of diameters (2-35 nm) and catalyst supports and reveals that dehydrogenation selectivities may be controlled by manipulating either.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA. dwflhrty@illinois.edu.
authors.forename: M E
authors.identifier: 0000-0003-1204-6711
authors.initials: ME
authors.lastname: Witzke
authors.affiliation: BP Group Research, Naperville, IL 60563, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Dietrich
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA. dwflhrty@illinois.edu.
authors.forename: M Y S
authors.initials: MY
authors.lastname: Ibrahim
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA. dwflhrty@illinois.edu.
authors.forename: K
authors.initials: K
authors.lastname: Al-Bardan
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA. dwflhrty@illinois.edu.
authors.forename: M D
authors.initials: MD
authors.lastname: Triezenberg
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA. dwflhrty@illinois.edu.
authors.forename: D W
authors.initials: DW
authors.lastname: Flaherty
mesh_terms: D000079:Acetaldehyde / Q000138:chemical synthesis / Q000737:chemistry; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D006865:Hydrogenation; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010316:Particle Size; D056928:X-Ray Absorption Spectroscopy
chemical_list: D000431:Ethanol; D003300:Copper; D000079:Acetaldehyde