Study the Effect of Presence of Graphene Oxide as Catalyst Support on Hydrogen Adsorption/Desorption Reactions in Proton Exchange Membrane Fuel Cells

Carbon is an ideal material for supporting metal nanocatalysts in proton exchange membrane fuel cells [1]. Among different allotropes of carbon, recently, graphene has beenstudied as a catalyst support due to its excellent conductivity, remarkable mechanical strength and vast surface area [1]. However, the inert and hydrophobic nature of graphene will be therate limiting steps in commercialization as a metal nanocatalyst support [2].In this study, we introduced hydrophilic and electrochemically active sites into graphene by grafting oxygenated functional groups onto graphene nanosheets surface, via a chemicalmethod. Then electrochemical behaviors of resultant graphene oxide toward hydrogen adsorption/desorption was investigated as support for electrocatalysts in proton exchangemembrane fuel cells. Finally, the effect of siting Nafion in graphene oxide layer was also studied. Graphene oxide was prepared from graphite powder using modified Hummers method. The effect of the presence of different percentage of oxygen functionalities on graphene oxide sheets and their subsequent impact on the electrochemical characteristics of the electrocatalyst layer was studied by varying the reaction time. The physicochemical characteristics of graphene oxide were studied by Fourier transform infrared, X-raydiffraction and thermal gravimetric analysis. The electrochemical tests were carried out by cyclic voltammetry using a three-electrode cell consists of a glassy carbon electrode as the working electrode, Ag/AgCl as the reference electrode, and platinum wire as the counter electrode with potential range of -1.0 to 1.0 V at scan rate of 30 mV s-1 in 1 M H2SO4 at ambient temperature

کلیدواژه ها:

Graphene oxide ، Hydrogen adsorption/desorption ، Metal nanocatalyst support ، Proton exchange membrane fuel cell