Synthesis and characterization of Pt-Au/C catalyst for glucose electro-oxidation for the application in direct glucose fuel cell

摘要

To minimize the poisoning of Pt-catalyst in glucose electro-oxidation for direct glucose fuel cell, carbon supported low metal loaded platinum-gold (Pt-Au/C) catalyst (1:1) was synthesized by immobilizing metal sols on carbon. The physical characterization of Pt-Au/ C, Pt/C and Au/C was carried out using transmission electron microscope (TEM), scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). SEM indicates the uniformity in loading of metals on Vulcan XC-72 carbon support, whereas TEM picture and XRD pattern confirm the formation of Pt-Au nanoparticles of less than 10 nm size. TGA shows the metal present in Pt-Au/C catalyst is 14.5% by wt. Electrochemical analysis such as cyclic voltammetry (CV) and chronoamperometry (CA) on Pt-Au/C and commercial Pt/C and Au/C (40 wt. % of metal) for glucose electro-oxidation in alkaline media shows that Pt-Au/C is capable of electro-oxidation of glucose at low potential as that of Pt/C catalyst and more active than Au/C catalyst. The poisoning rate of prepared Pt-Au/C (0.0046% s~(-1)) is lower than that of Pt-Ru/ C (0.0085% s~(-1)) and Pt/C (0.011% s~(-1)) catalysts. A batch cell operated using Pt-Au/C as anode and activated charcoal as cathode delivered 0.9 V OCV and 0.72 mW cm ~2 peak power density at 0.2 M glucose in 1 M KOH solution.