title: Characterizing Substrate-Surface Interactions on Alumina-Supported Metal Catalysts by Dynamic Nuclear Polarization-Enhanced Double-Resonance NMR Spectroscopy.
abstract: The characterization of nanometer-scale interactions between carbon-containing substrates and alumina surfaces is of paramount importance to industrial and academic catalysis applications, but it is also very challenging. Here, we demonstrate that dynamic nuclear polarization surface-enhanced NMR spectroscopy (DNP SENS) allows the unambiguous description of the coordination geometries and conformations of the substrates at the alumina surface through high-resolution measurements of13C-27Al distances. We apply this new technique to elucidate the molecular-level geometry of13C-enriched methionine and natural abundance poly(vinyl alcohol) adsorbed on γ-Al2O3-supported Pd catalysts, and we support these results with element-specific X-ray absorption near-edge measurements. This work clearly demonstrates a surprising bimodal coordination of methionine at the Pd-Al2O3interface.
authors.affiliation: Ames Laboratory, U.S. Department of Energy , Ames, Iowa 50011, United States.
authors.forename: Frédéric A
authors.initials: FA
authors.lastname: Perras
authors.affiliation: Department of Chemistry, Queen's University , Kingston, Ontario K7L 3N6, Canada.
authors.forename: J Daniel
authors.initials: JD
authors.lastname: Padmos
authors.affiliation: Department of Chemical and Biological Engineering, Iowa State University , Ames, Iowa 50011, United States.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Johnson
authors.affiliation: Ames Laboratory, U.S. Department of Energy , Ames, Iowa 50011, United States.
authors.forename: Lin-Lin
authors.initials: LL
authors.lastname: Wang
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin , Madison, Wisconsin 53706, United States.
authors.forename: Thomas J
authors.identifier: 0000-0002-2788-8519
authors.initials: TJ
authors.lastname: Schwartz
authors.affiliation: Ames Laboratory, U.S. Department of Energy , Ames, Iowa 50011, United States.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Chemistry, Queen's University , Kingston, Ontario K7L 3N6, Canada.
authors.forename: J Hugh
authors.initials: JH
authors.lastname: Horton
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin , Madison, Wisconsin 53706, United States.
authors.forename: James A
authors.identifier: 0000-0001-6542-0856
authors.initials: JA
authors.lastname: Dumesic
authors.affiliation: Department of Chemical and Biological Engineering, Iowa State University , Ames, Iowa 50011, United States.
authors.forename: Brent H
authors.initials: BH
authors.lastname: Shanks
authors.affiliation: Ames Laboratory, U.S. Department of Energy , Ames, Iowa 50011, United States.|Department of Chemical and Biological Engineering, Iowa State University , Ames, Iowa 50011, United States.|Department of Materials Science and Engineering, Iowa State University , Ames, Iowa 50011, United States.
authors.forename: Duane D
authors.initials: DD
authors.lastname: Johnson
authors.affiliation: Ames Laboratory, U.S. Department of Energy , Ames, Iowa 50011, United States.|Department of Chemistry, Iowa State University , Ames, Iowa 50011, United States.
authors.forename: Marek
authors.identifier: 0000-0001-7800-5336
authors.initials: M
authors.lastname: Pruski