PtCo alloy nanoparticles supported on graphene nanosheets with high performance for methanol oxidation

PtCo alloy nanoparticles are deposited onto graphene sheets through a facile and reproducible hydrothermal method. During the hydrothermal reaction, the reduction of graphene oxide and PtCo alloy nanoparticles loading can be achieved. X-ray diffraction (XRD) analyses reveal a good crystallinity of the supported Pt nanoparticles in the composites and the formation of PtCo alloy. X-ray photoelectron spectra (XPS) results depict that Pt mainly exists in the metallic form, while much of the cobalt is oxidized. Transmission electron microscope (TEM) observations show that the PtCo alloy nanoparticles are uniformly dispersed on graphene nanosheets compared with multiwalled carbon nanotubes (MWNTs). This PtCo-graphene composite exhibits excellent electrocatalytic activity and high poison tolerance toward poisoning species for methanol oxidation reaction, far outperforming the Pt-graphene or PtCo-MWNTs composites with the same feeding ratio of Pt/carbon.