PtSn/C alloyed and non-alloyed materials: Differences in the ethanol electro-oxidation reaction pathways

In the present work, the ethanol oxidation reaction (EOR) was investigated using PtSn/C electrocatalysts in the following two phases: 92% alloyed prepared by the polymeric precursor method (PPM) and 6% alloyed prepared by a sol–gel method (SGM). The TEM experiments show particle sizes of 3–5 nm for both catalysts. The electrocatalytic activity for both materials was investigated using chronoamperometry, and at 0.5 V vs. RHE, the current density for the EOR on the PPM material was approximately 5 times higher than on the SGM material. From in situ ATR-FTIR experiments, it can be seen that the non-alloyed materials led to CO2 formation with slow kinetics, whereas alloyed materials led to acetic acid formation with fast kinetics. The enhancement in the electrocatalytic behavior for ethanol oxidation was explained by acetic acid formation.

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► Ethanol oxidation on Pt3Sn1/C alloyed and non-alloyed assisted by FTIR “in situ”.
► The measured current density for ethanol oxidation on Pt3Sn/C alloyed is the highest.
► Non-alloyed PtSn/C led to CO2, while alloyed Pt3Sn/C led to acetic acid formation.