The preparation and mechanistic study of highly effective PtSnRu ternary nanorods catalysts toward ethanol oxidation reaction

While Pt-based anodes have shown promising electrochemical behaviors on the ethanol oxidation reaction (EOR) in the direct ethanol fuel cell (DEFC) application, a rational design for optimizing the structures and compositions of catalysts is yet to be fully understood, due largely to the lack of mechanistic insights of the catalytic reaction. Here, we systematically investigate EOR on Pt-based binary (PtSn and PtRu) and ternary (PtSnRu) nanorods with varied atomic ratios to elucidate the effects of chemical composition and structure on the electrochemical behavior. The electrochemical results show that Sn and Ru in the ternary PtSnRu NRs can effectively promote the EOR performance, both at 0.6 V (I06) and peak potential (Imax), than binary PtSn and PtRu NRs. The enhanced activity at low potential (I06) corresponds to the strengthen adsorption of water and ethanol on Ru site with high energetic d band structure; that at high potential (Imax) is related to the oxygen-containing species on surface Sn lowering the oxidation barriers through hydrogen-bond interaction, according to density-functional-theory-based calculations. The combination of electrochemical experiment on modeled binary and ternary electrodes and theoretical computation offers an effective approach to clarify the complex EOR mechanism and provides information vital to achieve realistic design of better EOR anodes.