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

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.