Bimetallic PtCu core-shell nanoparticles in PtCu/C electrocatalysts: Structural and electrochemical characterization

Composite metal-carbon electrocatalysts PtCu/C containing core-shell bimetallic PtCu nanoparticles were synthesized by sequential chemical reduction of Cu (II) and Pt (IV) in carbon suspension, prepared on the basis of ethylene glycol–water solvent. The characterization of "as prepared" and obtained after the acid treatment PtCu nanoparticles was performed by TEM, XRD, Pt L3- and Cu K-edge extended X-ray absorption fine structures (EXAFS). The technique and computational code were proposed for visualization of components distribution over the volume of cluster, which represents the mean bimetallic nanoparticle, according to the values of structural parameters derived from EXAFS. By this technique, the cluster models of PtCu nanoparticles before and after acid treatment, reflecting the character of components' distribution, were generated. The study of electrochemical performances of the obtained PtCu/C electrocatalyst revealed the similar oxygen reduction reaction (ORR) activity and increased durability compared to commercial Pt/C electrocatalyst E-TEK 20.