The effect of Ni addition on the structure of Pt–Sn/C nanoparticles by electron microscopy

Carbon supported bimetallic Pt–Sn and trimetallic Pt–Sn–Ni nanoparticles were synthesized by Bönnemannʹs colloidal precursor method and characterized by high-resolution transmission electron microscopy (HR-TEM) and energy dispersive X-ray analysis (EDX) techniques. HR-TEM and EDX results demonstrated that SnO2 nanoparticles tend to form clusters in Pt–Sn/C; however, the presence of Ni in the Pt–Sn/C gives rise to an induced interaction between SnO2 and Pt nanoparticles. Electron diffraction patterns of Pt–Sn–Ni/C showed that either cubic Pt or PtSn2 structures are present. From the selected area EDX analysis, it was found that both of these structures contain Sn. This suggests that Pt–Sn–Ni/C nanoparticles may be partially covered by Sn-richer PtSn2 alloyed structure.