Structural characterization of carbon-supported platinum-ruthenium nanoparticles from the molecular cluster precursor PtRu5C(CO)16

Michael S. Nashner, Anatoly I. Frenkel, David L. Adler, John R. Shapley, Ralph G. Nuzzo

Research output: Contribution to journalArticlepeer-review


We describe the preparation and structural characterization of carbon-supported Pt-Ru nanoparticles with exceptionally narrow size and compositional distributions. The supported bimetallic particles are obtained by reduction of the neutral molecular carbonyl cluster precursor PtRu5C(CO)16 with hydrogen. A detailed structural model of the nanoparticles has been deduced on the basis of studies by in situ extended X-ray absorption fine structure spectroscopy (EXAFS), scanning transmission electron microscopy, microprobe energy-dispersive X-ray analysis, and electron microdiffraction. These experiments show that the bimetallic nanoparticles have a Pt:Ru composition of 1:5 and an average diameter of ca. 1.5 nm and adopt a face-centered cubic closest packing structure. These results demonstrate a marked sensitivity of the metal particle structure to nanoscale size effects inasmuch as the thermodynamically stable phase for bulk alloys of this composition is hexagonal close-packed. The local metal coordination environment, revealed by multiple scattering analysis of the EXAFS data, shows the presence of a nonstatistical distribution of different metal atoms in the nanoparticles. Specifically, Pt shows a marked preference for segregation to the particle surfaces under an ambient H2 atmosphere. Oxidation of the alloy particle hi O2 produces an outer metal oxide layer surrounding a metal-only core. This oxidation is easily reversed by exposing the nanoparticles to H2 at room temperature.

Original languageEnglish (US)
Pages (from-to)7760-7771
Number of pages12
JournalJournal of the American Chemical Society
Issue number33
StatePublished - Aug 20 1997

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry


Dive into the research topics of 'Structural characterization of carbon-supported platinum-ruthenium nanoparticles from the molecular cluster precursor PtRu5C(CO)16'. Together they form a unique fingerprint.

Cite this