Pt-Au nanoparticles on graphene for oxygen reduction reaction: Stability and performance on proton exchange membrane fuel cell

Pt and Pt-Au nanoparticles supported on reduced graphene oxide (rGO) were synthesized by reverse microemulsion method with metal loading of 20 wt% and 10: 10 wt%, respectively. The nanomaterials were characterized by Raman, X-ray diffraction, thermogravimetric analysis and transmission electronic microscope. The obtained materials were evaluated as electrocatalysts for Oxygen Reduction Reaction (ORR), obtaining the highest catalytic activity with Pt-Au/rGO compared to Pt/rGO; besides, the stability of the catalyst is determined until 50,000 cycles. Pt-Au/rGO was used to prepare membrane electrode assembly (MEA), in order to study the performance of this nanomaterial in the proton exchange membrane fuel cell (PEMFC). The maximum power density is 20 mW cm−2 and 70 mW cm−2 for Pt/rGO and Pt-Au/rGO, respectively, those values increased up to 365 mW cm−2, when Pt-Au nanoparticles supported on multiwall carbon nanotubes (CNT) was used as spacer. •Pt-Au/rGO were synthesized by reverse microemulsion, obtaining particle size below 3 nm.•Pt-Au/rGO exhibited better performance for ORR catalytic activity than Pt/rGO.•The stability of the Pt-Au/rGO was remarkable compared to other reported catalysts.•Pt-Au/rGO was used to prepare MEAs and fuel cell evaluation was performed.•The power density at fuel cell increases up to 5.2 times when a spacer is added.