Microfluidic Synthesis and Characterization of FePtSn/C Catalysts with Enhanced Electro-Catalytic Performance for Direct Methanol Fuel Cells

Carbon supported FePt and FePtSn alloy nanocrystals were synthesized via a hybrid microfluidic-batch process. Their microstructures and compositions were characterized by transmission electron microscopy, high resolution transmission electron microscope, energy dispersive X-ray spectrometer, X-ray powder diffraction and X-ray photoelectric spectroscopy. All the nanocatalysts show a homogeneous distribution of ultra-small alloy nanoparticles (∼2-3 nm) on the surface of carbon black. The electrochemical results indicate that FePtSn/C nanocatalysts have more excellent catalytic activity for methanol oxidation compared with Pt/C catalyst. Chronoamperometry measurements were performed at 0.45 V for 3600 s. At 3600 s, the mass specific activity of FePtSn/C (Sn at% = 14) can retain 103 mA mgPt−1, about 10 times higher than that of Pt/C catalyst (10 mA mgPt−1). The CO-stripping tests indicate that FePtSn/C (Sn at% = 14) nanocatalysts preserve a high electrochemical active specific surface and a higher ability to resist poisons, thus making the FePtSn/C (Sn at% = 14) catalyst an excellent electrocatalyst for direct methanol fuel cells.