Ultralow Pt amount of Pt–Fe alloys supported on ordered mesoporous carbons with excellent methanol tolerance during oxygen reduction reaction. (30th January 2016)

• Record Type: Journal Article
• Authors: Zheng, Feng-Sheng; Liu, Shou-Heng; Kuo, Chung-Wen
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 4(2016)
• Page Start: 2487
• Page End: 2497
• Publication Date: 2016-01-30
• Subjects: Ordered mesoporous carbons -- Non-noble alloy -- Methanol resistant -- Oxygen reduction reaction -- X-ray absorption spectroscopy; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2015.12.018
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The synthesis of ordered mesoporous carbons supported various atomic ratios of Pt–Fe nanoparticles (Ptx Fe100−x /OMC) with low Pt loading and high Pt–Fe alloying extent is reported. The resultant Ptx Fe100−x /OMC have been thoroughly characterized by a variety of different spectroscopic techniques and used as electrocatalysts during oxygen reduction reaction (ORR) for direct methanol fuel cell (DMFC) at cathode. Results obtained from X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicate that the Pt metal in the Ptx Fe100−x /OMC is formed in the face-centered cubic (fcc) crystalline structure and composed of Pt(0) and Pt oxides. By using N2 adsorption/desorption isotherms, transmission electron microscopy (TEM), it was found that Pt–Fe alloy nanoparticles (3–5 nm) homogeneously dispersed on the mesoporous carbon supports with high surface areas (>1000 m 2 g −1 ) and regular pore channels (ca. 3.4 nm) for all Ptx Fe100−x /OMC. Further studies by X-ray absorption spectroscopy (XAS) reveal that the Pt-richshell –Fe-richcore microstructure with a higher Pt–Fe alloying state is accountable for the superior ORR performance observed for the Ptx Fe100−x /OMC, as compared to the commercial electrocatalysts. Among the various Ptx Fe100−x /OMC catalysts, the Pt45 Fe55 /OMC exhibits the highest ORR performance, methanol-tolerant capability and ultralow Pt content, which should have potential applications as cathodic catalysts in DMFC. Highlights: Well-dispersed and highly alloying PtFe on OMC was prepared via a simple route. The Pt45 Fe55 /OMC has superior catalytic performance compared to typical catalysts. Well-dispersed and highly-alloyed PtFe nanoparticles result in this enhancement.