Synthesis and catalytic property of PtSn/C Toward the ethanol oxidation reaction

Nanosized PtSn/C catalysts with good dispersion and high catalytic activity toward the ethanol oxidation reaction (EOR) were prepared successfully by an alcohol reduction process. The pH value of the refluxing solution during the preparation was controlled at 9 or 12 to enhance the EOR activity of the prepared catalysts. The compositions, phase structures, morphological properties, EOR activity and durability of the electrocatalysts were characterized by energy dispersive spectrometry, X-ray diffraction, high-resolution transmission electron microscopy, cyclic voltammetry, and a long term test, respectively. It was found that for the PtSn/C catalysts the particle size, EOR activity and durability are affected by the pH value during the preparation. Because of the formation of SnO2 phases, the PtSn/C prepared at pH 12 (Sn12) has a smaller particle size than that prepared at pH 9 (Sn9). Both the Sn9 and Sn12 samples show a lower onset potential and a higher Pt mass current density in the low potential region for the EOR compared with commercial Pt/C. The Pt mass current density at E = 0.6 V (I ₀₆) is 33.1, 16.5, and 12.4 mA/mg for Sn12, Sn9, and Pt/C, respectively. For the chronoamperometry test, the activity of the Sn12 catalysts is much higher than that of Pt/C after 3600 s suggesting that the Sn12 catalysts have better stability and poisoning tolerance.