A PtFe/C catalyst has been synthesized by impregnation and high-temperature reduction followed by acid-leaching. X-ray diffraction, X-ray photoelectron spectroscopy and X-ray atomic near edge spectroscopy characteriza...A PtFe/C catalyst has been synthesized by impregnation and high-temperature reduction followed by acid-leaching. X-ray diffraction, X-ray photoelectron spectroscopy and X-ray atomic near edge spectroscopy characterization reveal that PtgFe alloy formation occurs during high-temperature reduction and that unstable Fe species are dissolved into acid solution. The difference in Fe concentration from the core region to the surface and strong O-Fe bonding may drive the outward diffusion of Fe to the highly corrugated Pt-skeleton, and the resulting highly dispersed surface FeOx is stable in acidic medium, leading to the construction of a PtBFe@Pt-FeOx architecture. The as prepared PtFe/C catalyst demonstrates a higher activity and comparable durability for the oxygen reduction reaction compared with a Pt/C catalyst, which might be due to the synergetic effect of surface and subsurface Fe species in the PtFe/C catalyst.展开更多
基金This work was financially supported by the Ministry of Science and Technology of China （Grants 2012CB215500 and 2013CB933100） and the National Natural Science Foundation of China （Grants 21103178 and 21033009）.
文摘A PtFe/C catalyst has been synthesized by impregnation and high-temperature reduction followed by acid-leaching. X-ray diffraction, X-ray photoelectron spectroscopy and X-ray atomic near edge spectroscopy characterization reveal that PtgFe alloy formation occurs during high-temperature reduction and that unstable Fe species are dissolved into acid solution. The difference in Fe concentration from the core region to the surface and strong O-Fe bonding may drive the outward diffusion of Fe to the highly corrugated Pt-skeleton, and the resulting highly dispersed surface FeOx is stable in acidic medium, leading to the construction of a PtBFe@Pt-FeOx architecture. The as prepared PtFe/C catalyst demonstrates a higher activity and comparable durability for the oxygen reduction reaction compared with a Pt/C catalyst, which might be due to the synergetic effect of surface and subsurface Fe species in the PtFe/C catalyst.
