In situ diffraction of highly dispersed supported platinum nanoparticles

摘要

For catalytic metal nanoparticles (2 nm) where diffraction patterns of the metallic phase are obtainable in air, we show that on exposure to air the surface is oxidized with a metallic core producing misleading results with respect to particle size and lattice parameter. Results from XRD are cross-correlated with scanning transmission electron microscopy and three other synchrotron X-ray techniques, small angle diffraction (SAXS), pair distribution function (PDF) and X-ray absorption spectroscopy (XAS), to provide detailed characterization of the structure of very small nanoparticles in the metallic phase.