The effect of thermal treatment on the atomic structure of PtCu core-shell nanoparticles in PtCu/C electrocatalysts

Nanocatalysts PtCu/C with core-shell structure of PtCu nanoparticles were synthesized by the method of sequential chemical reduction of Cu²⁺ and Pt(IV) in carbon suspension, prepared on the basis of ethylene glycol–water solvent. The characterization of atomic structure of "as prepared" PtCu nanoparticles and obtained after thermal treatment at 350 °C was performed by Pt L ₃- and Cu K -edge extended X-ray absorption fine structure (EXAFS), complemented with TEM and XRD studies. The processing of EXAFS was performed by the technique that enables to reduce the effect of correlations among fitting parameters on the determined values of local structure parameters of the absorbing atoms, which have the nearest surrounding consisting both Pt and Cu atoms. (paper)