Synthesis and solid-state structure of a Pt-Ru-P ternary metal phosphide (PtRuP2) as a carbon nanocomposite.

Reactive thermal degradation of Pt(PPh3)(Cl)(mu2-Cl)2Ru(Cl)(eta3:eta3-C10H16)/Vulcan carbon powder composites gives a nanocomposite powder containing nanocrystals of the expected PtRu alloy phase along with nanocrystals of an unknown substance. Yields of the unknown phase increase when PPh3 is added to the composite prior to thermal treatment. The new substance has been identified as a ternary metal phosphide, PtRuP2. Full-profile Rietveld analysis of the XRD pattern of this phase is consistent with a primitive Pm3m cubic unit cell (CsCl-type) having a cell constant of 2.78 A. Fully disordered Pt and Ru atoms occupy the (0, 0, 0) atomic positions with P atoms occupying interstitial sites at the (1/2, 1/2, 1/2) atomic positions.