• DOI:10.1063/1.2101487
• Corpus ID: 33696621

The application of infrared spectroscopy to probe the surface morphology of alumina-supported palladium catalysts.

@article{Lear2005TheAO,
  title={The application of infrared spectroscopy to probe the surface morphology of alumina-supported palladium catalysts.},
  author={Timothy Lear and Robert Marshall and Jose Antonio Lopez-Sanchez and Samuel David Jackson and Thomas M. Klap{\"o}tke and Marcus B{\"a}umer and G{\"u}nther Rupprechter and Hans‐Joachim Freund and David Lennon},
  journal={The Journal of chemical physics},
  year={2005},
  volume={123 17},
  pages={
          174706
        }
}

• T. Lear, R. Marshall, +6 authors D. Lennon
• Published 1 November 2005
• Chemistry
• The Journal of chemical physics

Five alumina-supported palladium catalysts have been prepared from a range of precursor compounds [palladium(II) nitrate, palladium(II) chloride, palladium(II) acetylacetonate, and tetraamminepalladium(II) tetraazidopalladate(II)] and at different metal loadings (1-7.3 wt %). Collectively, this series of catalysts provides a range of metal particle sizes (1.2-8.5 nm) that emphasize different morphological aspects of the palladium crystallites. The infrared spectra of chemisorbed CO applied under pulse-flow conditions reveal distinct groupings between metal crystallites dominated by low index planes and those that feature predominantly corner/edge atoms. Temperature-programmed infrared spectroscopy establishes that the linear CO band can be resolved into contributions from corner atoms and a combination of (111)(111) and (111)(100) particle edges. Propene hydrogenation has been used as a preliminary assessment of catalytic performance for the 1 wt % loaded catalysts, with the relative inactivity of the catalyst prepared from palladium(II) chloride attributed to a diminished hydrogen supply due to decoration of edge sites by chlorine originating from the preparative process. It is anticipated that refinements linking the vibrational spectrum of a probe molecule with surface structure and accessible adsorption sites for such a versatile catalytic substrate provide a platform against which structure/reactivity relationships can be usefully developed.