教師著作

Permanent URI for this collectionhttp://rportal.lib.ntnu.edu.tw/handle/20.500.12235/37076

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Author: search.filters.author.Y.-C. LinHas files: No

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    Simple Replacement Reaction for the Preparation of Ternary Fe1?xPtRux Nanocrystals with Superior Catalytic Activity in Methanol Oxidation Reaction.
    (American Chemical Society, 2012-06-20) D.-Y. Wang; H.-L. Chou; Y.-C. Lin; F.-J. Lai; C.-H. Chen; J.-F. Lee; B.-J. Hwang; Chia-Chun Chen
    The finding of new metal alloyed nanocrystals (NCs) with high catalytic activity and low cost to replace PtRu NCs is a critical step toward the commercialization of fuel cells. In this work, a simple cation replacement reaction was utilized to synthesize a new type of ternary Fe1–xPtRux NCs from binary FePt NCs. The detailed structural transformation from binary FePt NCs to ternary Fe1–xPtRux NCs was analyzed by X-ray absorption spectroscopy (XAS). Ternary Fe35Pt40Ru25, Fe31Pt40Ru29, and Fe17Pt40Ru43 NCs exhibit superior catalytic ability to withstand CO poisoning in methanol oxidation reaction (MOR) than do binary NCs (FePt and J-M PtRu). Also, the Fe31Pt40Ru29 NCs had the highest alloying extent and the lowest onset potential among the ternary NCs. Furthermore, the origin for the superior CO resistance of ternary Fe1–xPtRux NCs was investigated by determining the adsorption energy of CO on the NCs’ surfaces and the charge transfer from Fe/Ru to Pt using a simulation based on density functional theory. The simulation results suggested that by introducing a new metal into binary PtRu/PtFe NCs, the anti-CO poisoning ability of ternary Fe1–xPtRux NCs was greatly enhanced because the bonding of CO–Pt on the NCs’ surface was weakened. Overall, our experimental and simulation results have indicated a simple route for the discovery of new metal alloyed catalysts with superior anti-CO poisoning ability and low usage of Pt and Ru for fuel cell applications.
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    Tunable properties of Pt(x)Fe(1-x) electrocatalysts and their catalytic activity towards the oxygen reduction reaction
    (Royal Society of Chemistry, 2010-04-01) F.-J. Lai; H.-L. Chou; L. S. Sarma; D.-Y. Wang; Y.-C. Lin; J.-F. Lee; B.-J. Hwang; Chia-Chun Chen
    We present the controlled synthesis of bimetallic PtxFe1−x nanoparticles with tunable physical properties and a study of their catalytic activity towards the oxygen reduction reaction (ORR). Composition-induced variations in alloying extent and Pt d-band vacancies in Pt–Fe/C catalysts are systematically investigated. Density functional theoretical calculations are performed in order to realize the electronic effect caused by alloying Pt with Fe. The DFT computational observations revealed that iron donates electrons to platinum, when the Fe 3d and Pt 5d orbitals undergo hybridization. The PtxFe1−x catalysts with various Pt-to-Fe atomic ratios are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), and X-ray absorption spectroscopy (XAS). TEM images indicate that the dispersion of the metal nanoparticles is uniform and the XAS technique provides significant insight on Pt d-band vacancies and the alloying extent of Pt and Fe in PtxFe1−x nanoparticles. Rotating-disk voltammetry of PtxFe1−x nanoparticle catalysts with various Pt : Fe atomic compositions (3 : 1, 1 : 1, and 1 : 3) revealed that the Pt1Fe1/C nanocatalyst showed a greater enhancement in ORR activity than platinum. The enhanced catalytic activity toward ORR is attributed to the higher alloying extent of platinum and iron as well as the promising electronic structure offered by the lower unfilled Pt d states in PtxFe1−x nanoparticles when compared to pure Pt.
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    A Chain-Structure Nanotube: Growth and Characterization of Single-Crystal Sb2S3 Nanotubes via a Chemical Vapor Transport Reaction
    (Wiley-VCH Verlag, 2004-04-01) J. Yang; Y.-C. Lin; H.-M. Liu; Chia-Chun Chen
    Single-crystal Sb2S3 nanotubes with chain-like structures (see Figure) have been successfully synthesized by chemical vapor transport using sulfur as the transport agent. Detailed characterization of the nanotubes shows the growth direction of Sb2S3 nanotubes is determined by the crystallographic orientation of the chain-like building blocks. A mechanism explaining the formation of the nanotubes is presented.