Facile synthesis of PtAu nanoparticles supported on polydopamine reduced and modified graphene oxide as a highly active catalyst for methanol oxidation

•GO could be reduced and modified simultaneously by PDA without using reducing agents.•PDA plays an important role in enhancing the dispersion and stability of the catalyst.•The bimetallic PtAu/PDA-RGO catalysts exhibits higher catalytic activity than the monometallic Pt/PDA-RGO toward MOR.•The PtAu(3:1)/PDA-RGO catalyst also shows better catalytic activity for MOR than PtAu(3:1)/RGO and PtAu(3:1)/C catalysts.

In this paper, a facile strategy for the synthesis of PtAu nanoparticles (NPs) with different Pt/Au ratios supported on polydopamine reduced and modified graphene oxide (PtAu/PDA-RGO) is reported. The as-prepared PtAu/PDA-RGO composites were extensively analyzed by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Raman spectroscopy, energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. It is found that PDA plays an important role in enhancing the dispersion and stability of the catalyst. Moreover, the bimetallic PtAu/PDA-RGO catalysts exhibits higher catalytic activity than the monometallic Pt/PDA-RGO toward methanol oxidation reaction (MOR), with the best performance found for the Pt/Au molar ratio of 3/1. The PtAu(3:1)/PDA-RGO catalyst also shows better catalytic activity for MOR than PtAu(3:1)/RGO and PtAu(3:1)/C catalysts, suggesting that PDA-RGO can be a promising catalyst support for fuel cells. These findings also indicate that the molar ratios of Pt/Au and the catalyst support are the two critical factors to affect the overall performance of the catalyst.

Graphical abstractA facile and clean method for the synthesis of PtAu nanoparticles with different Pt/Au ratios supported on polydopamine reduced and modified graphene oxide (PtAu/PDA-RGO) is reported, which exhibit higher electro-catalytic performance and stability towards methanol oxidation in alkaline medium.Figure optionsDownload full-size imageDownload as PowerPoint slide