Synthesis and characterization of quaternary PtRuIrSn/C electrocatalysts for direct ethanol fuel cells

To find a more durable anode with high performance for direct ethanol fuel cells (DEFCs), the present study investigates a series of quaternary electrocatalysts, Pt 30 Ru 30 Ir 40− x Sn x /C (wt.%), for the ethanol electro-oxidation reaction (EOR). The carbon-supported Pt 30 Ru 30 Ir 40− x Sn x /C electrocatalysts were prepared by a known impregnation-reduction (borohydride) method. The microstructure and chemical composition were determined by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The activity of the electrocatalysts for EOR was compared to commercial Pt 67 Ru 33 /C (HISPEC5000) using linear sweep voltammetry (LSV) based on similar Pt loading. The results of this study show that electrocatalyst composition with 10 and 20% Ir (wt.%) exhibit higher electrocatalytic activity than the commercial PtRu electrocatalyst. The single fuel cell testing at 90 °C comparing Pt 30 Ru 30 Ir 40− x Sn x /C to commercial Pt 67 Ru 33 /C and Pt 83 Sn 17 /C anodes showed an enhancement of Pt activity (normalized to Pt loading) in the following order: Pt 30 Ru 30 Ir 10 Sn 30 > Pt 30 Ru 30 Sn 40 ≥ Pt 30 Ru 30 Ir 40 ≥ Pt 83 Sn 17 > Pt 67 Ru 33 . After a long-term performance test, the activity changed to the following order: Pt 30 Ru 30 Ir 10 Sn 30 > Pt 30 Ru 30 Ir 40 > Pt 30 Ru 30 Sn 40 > Pt 83 Sn 17 > Pt 67 Ru 33 . Pt 30 Ru 30 Ir 10 Sn 30 /C exhibited both a higher performance with a specific power density of 29 mW mg Pt −1 without O 2 backpressure at the cathode and an excellent long-term stability in a DEFC operating at 90 °C.