In situ X-ray absorption spectroscopy on probing the enhanced electrochemical activity of ternary PtRu@Pb catalysts

The cumulative synergistic effect generated by the combination of the components is a promising route for developing active ternary catalysts with reduced Pt content. In this article, synthesis, electrochemical property and in situ X-ray absorption spectroscopy (XAS) of a novel ternary catalyst PtRu@Pb/C have been reported. This ternary PtRu@Pb/C catalyst shows tenfold increase in the peak current density for methanol oxidation reaction (MOR) in comparison to the commercial state-of-the-art PtRu catalyst. To understand the mechanistic pathways and plausible reasons behind higher current density of PtRu@Pb, XAS and Δμ analysis in combination with ab initio FEFF8 calculations have been performed. The results reveal the direct evidence of strong charge transfer from lead to platinum shedding the light on this enhanced activity. The electrochemical study in conjunction with the in situ spectroscopy affirms the different role played by Pb and Ru, where ligand mechanism is induced by Pb and the bi-functional mechanism is mostly operated by ruthenium both being responsible in the enhancement of high current density for MOR.

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