CMK-5 Mesoporous Carbon Synthesized via Chemical Vapor Deposition of Ferrocene as Catalyst Support for Methanol Oxidation

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• 作者：Zhibin Lei ; Shiying Bai ; Yi Xiao ; Liqin Dang ; Lizhen An ; Guangning Zhang ; Qian Xu
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：January 24, 2008
• 年：2008
• 卷：112
• 期：3
• 页码：722 - 731
• 全文大小：660K
• 年卷期：v.112,no.3(January 24, 2008)
• ISSN：1932-7455

文摘

A novel and effective method was described in this work to prepare two-dimensional hexagonally orderedmesoporous CMK-5 carbon materials. This method is based on the chemical vapor deposition (CVD) offerrocene in the mesopores of SBA-15 at 500 C, followed by graphitization at different temperatures. Boththe silica/carbon composite and the resulting CMK-5 were characterized by N₂ adsorption, powder X-raydiffraction, Raman spectroscopy, transmission electron microscopy, high-resolution transmission electronmicroscopy (HRTEM), and thermogravimetric analysis. It was found that the ferrocene could be used as anew precursor to prepare CMK-5 nanopipes, with pipe thicknesses varying from 0.8 to 2.6 nm, by increasingthe CVD time from 20 to 120 min. The resulting CMK-5 exhibits high Brunauer-Emmett-Teller (BET)surface area (1044-2449 m²/g) and large pore volume (1.13-2.20 cm³/g). The graphitization degree of theresulting CMK-5 was investigated by pyrolyzing the corresponding silica/carbon composite at differenttemperatures. Pyrolysis temperatures below 850 C led to gradually improved graphitization degrees of CMK-5nanopipes. Pyrolysis temperatures above 850 C resulted in the partial collapse of ordered CMK-5 nanopipesaccompanied by the appearance of a considerable amount of entangled graphitic ribbons. The structuralevolution process of CMK-5 from ordered nanopipes to the final entangled graphitic ribbons was observedby HRTEM. The obtained CMK-5 was applied as a catalyst support of Pt for methanol oxidation. Theelectrochemical activities of Pt nanoparticles loaded on the CMK-5 carbon materials were investigated bycyclic voltammograms and compared with the commercial Pt/Vulcan XC-72 catalyst. It was found that thespecific mass activity of Pt/CMK-5 was much higher than Pt/Vulcan XC-72.