Study of carbon-supported bimetallic PtCu nanoparticles by ASAXS

Bimetallic platinum-copper nanoparticles on carbon support are studied as a perspective electrochemical catalyst by anomalous small-angle X-ray scattering near the Pt absorption L3-edge. The simultaneous fitting of several diffraction patterns measured at different photon energies lead to a satisfactory agreement between experimental and model curves in the assumption of core-shell structure of the particles with Pt-rich shell and Cu-rich core. It is shown that the average size of as prepared nanoparticles is about 6 nm with distribution spread of about ±2 nm and with thickness of Pt-rich shell approximately 1.6 nm. After annealing at 350◦C the average size of the particles increased by two times with additional enlargement of the Pt-rich shell thickness.