Effects of adsorbate coverage and bond-length disorder on the d-band center of carbon-supported Pt catalysts

Matthew W. Small, Joshua J. Kas, Kristina O. Kvashnina, John J. Rehr, Ralph G. Nuzzo, Moniek Tromp, Anatoly I. Frenkel

Research output: Contribution to journalArticlepeer-review

Abstract

Determination of the factors that affect the d-band center of catalysts is required to explain their catalytic properties. Resonant inelastic X-ray scattering (RIXS) enables direct imaging of electronic transitions in the d-band of Pt catalysts in real time and in realistic environmental conditions. Through a combination of in situ, temperature-resolved RIXS measurements and theoretical simulations we isolated and quantified the effects of bond-length disorder and adsorbate coverage (CO and H2) on the d-band center of 1.25 nm size Pt catalysts supported on carbon. We found that the decrease in adsorbate coverage at elevated temperatures is responsible for the d band shifts towards higher energies relative to the Fermi level, whereas the effect of the increase in bond-length disorder on the d-band center is negligible. Although these results were obtained for a specific case of non-interacting support and weak temperature dependence of the metal-metal bond length in a model catalyst, this work can be extended to a broad range of real catalysts. Don't let disorder bother you: Using resonant inelastic X-ray scattering (RIXS) measurements the changes in the d-band center of carbon-supported Pt nanocatalysts are imaged in response to variable temperatures and gas atmospheres. Theoretical analysis of RIXS data reveals that the d-band-center shift toward the Fermi level at elevated temperatures is dominated by the decrease in adsorbate coverage, whereas the increase of bond-length disorder plays no significant role.

Original languageEnglish (US)
Pages (from-to)1569-1572
Number of pages4
JournalChemPhysChem
Volume15
Issue number8
DOIs
StatePublished - Jun 6 2014

Keywords

  • catalysis
  • nanoparticles
  • platinum
  • resonant inelastic X-ray scattering
  • X-ray absorption spectroscopy

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Atomic and Molecular Physics, and Optics

Fingerprint Dive into the research topics of 'Effects of adsorbate coverage and bond-length disorder on the d-band center of carbon-supported Pt catalysts'. Together they form a unique fingerprint.

Cite this