Ternary Pt/Re/SnO₂/C catalyst for EOR: Electrocatalytic activity and durability enhancement

Carbon-supported Pt/C, Pt/Re/C, Pt/SnO₂/C and Pt/Re/SnO2/C, with 20 wt.% overall metal loading were prepared and their electrochemical activity towards ethanol oxidation reaction (EOR) was investigated. Transmission electron microscopy (TEM) combined with energy dispersive X-ray spectroscopy (EDS) revealed, that indeed binary and ternary combinations of the designed nanoparticles (NPs) were formed and successfully uniformly deposited on a carbon support. Fourier transform infrared spectroscopy (FTIR) allowed to assess the chemical composition of the nanocatalysts and X-ray diffraction (XRD) allowed to determine the catalyst structure. Potentiodynamic and chronoamperometric measurements were used to establish its catalytic activity and stability. The influence of Re addition on the electrochemical activity towards ethanol oxidation reaction (EOR) was verified. Indeed, the addition of Re to the binary Pt/SnO₂/C catalyst leads to the formation of ternary Pt/Re/SnO₂/C with physical contact between the individual NPs, enhancing the EOR. Furthermore, the onset potential of the synthesized ternary catalyst is shifted to more negative potentials and the current densities and specific activity are nearly 11 and 5 times higher, respectively, than for commercial Pt catalyst. Additionally ternary Pt/Re/SnO₂/C catalyst retained 96% of its electrochemical surface area.