Hydrogen Spillover in Pt-Single-Walled Carbon Nanotube Composites: Formation of Stable C鈭扝 Bonds

详细信息    查看全文

• 作者：Ranadeep Bhowmick ; Srivats Rajasekaran ; Daniel Friebel ; Cara Beasley ; Liying Jiao ; Hirohito Ogasawara ; Hongjie Dai ; Bruce Clemens ; Anders Nilsson
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：April 13, 2011
• 年：2011
• 卷：133
• 期：14
• 页码：5580-5586
• 全文大小：981K
• 年卷期：v.133,no.14(April 13, 2011)
• ISSN：1520-5126

文摘

Using in situ electrical conductivity and ex situ X-ray photoelectron spectroscopy (XPS) measurements, we have examined how the hydrogen uptake of single-walled carbon nanotubes (SWNTs) is influenced by the addition of Pt nanoparticles. The conductivity of platinum-sputtered single-walled carbon nanotubes (Pt-SWNTs) during molecular hydrogen exposure decreased more rapidly than that of the corresponding pure SWNTs, which supports a hydrogenation mechanism facilitated by 鈥渟pillover鈥?of dissociated hydrogen from the Pt nanoparticles. C 1s XPS spectra indicate that the Pt-SWNTs store hydrogen by means of chemisorption, that is, covalent C鈭扝 bond formation: molecular hydrogen charging at elevated pressure (8.27 bar) and room temperature yielded Pt-SWNTs with up to 16 卤 1.5 at. % sp³-hybridized carbon atoms, which corresponds to a hydrogen-storage capacity of 1.2 wt % (excluding the weight of Pt nanoparticles). Pt-SWNTs prepared by the Langmuir鈭払lodgett (LB) technique exhibited the highest Pt/SWNT ratio and also the best hydrogen uptake.