Study of Pt catalyst on graphene and its application to fuel cell

In this work Pt nanoparticles on graphene (PtNPs/GN) were formed from graphite oxide by two routes (one-step and two-step routes). For one-step route, a fixed weight of graphene oxide (GO) and a variable weight of H2PtCl6·6H2O were put in ethylene glycol for a reflux at 120 and 150 °C for 3, 6, 12 and 24 h, respectively. For the two-step route, the first step is reduction of GO films by sodium tetrahydridoborate to obtain graphene. Then, the graphene deposited with Pt particles was put in ethylene glycol for a reflux at 120, 150 and 180 °C for 3, 6, 12 and 24 h. The results show that the electrode catalyst Pt particles have a smaller size and a better distribution on the surface of graphene under the following reducing condition: two-step reduction, reaction time of 12 h, reaction temperature of 150 °C and the 1 g/L of H2PtCl6. These PtNPs/GN composites exhibit superior electrochemically active surface area and high poison tolerance toward methanol oxidation compared to Vulcan XC-72-Pt with the same Pt content. This revealed that the PtNPs/GN can be used as promising electrocatalyst support for direct methanol fuel cells.