title: Active sites and mechanisms for H₂O₂ decomposition over Pd catalysts.
abstract: A combination of periodic, self-consistent density functional theory (DFT-GGA-PW91) calculations, reaction kinetics experiments on a SiO2-supported Pd catalyst, and mean-field microkinetic modeling are used to probe key aspects of H2O2 decomposition on Pd in the absence of cofeeding H2 We conclude that both Pd(111) and OH-partially covered Pd(100) surfaces represent the nature of the active site for H2O2 decomposition on the supported Pd catalyst reasonably well. Furthermore, all reaction flux in the closed catalytic cycle is predicted to flow through an O-O bond scission step in either H2O2 or OOH, followed by rapid H-transfer steps to produce the H2O and O2 products. The barrier for O-O bond scission is sensitive to Pd surface structure and is concluded to be the central parameter governing H2O2 decomposition activity.
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI 53706;
authors.forename: Anthony
authors.initials: A
authors.lastname: Plauck
authors.affiliation: Core R&D-Inorganic Materials and Heterogeneous Catalysis, The Dow Chemical Company, Midland, MI 48674.
authors.forename: Eric E
authors.initials: EE
authors.lastname: Stangland
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI 53706; jdumesic@wisc.edu emavrikakis@wisc.edu.
authors.forename: James A
authors.initials: JA
authors.lastname: Dumesic
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI 53706; jdumesic@wisc.edu emavrikakis@wisc.edu.
authors.forename: Manos
authors.initials: M
authors.lastname: Mavrikakis
keywords: catalysis; density functional theory; hydrogen peroxide; microkinetic analysis; palladium