Web Release Date: January 1,
CMK-5 Mesoporous Carbon Synthesized via Chemical Vapor Deposition of Ferrocene as Catalyst Support for Methanol Oxidation
and
Institute of Chemistry for Functionalized Materials, Faculty of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian, Liaoning, 116029, China, and State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
Received: September 12, 2007
In Final Form: October 31, 2007
Abstract:
A novel and effective method was described in this work to prepare two-dimensional hexagonally ordered
mesoporous CMK-5 carbon materials. This method is based on the chemical vapor deposition (CVD) of
ferrocene in the mesopores of SBA-15 at 500 
C, followed by graphitization at different temperatures. Both
the silica/carbon composite and the resulting CMK-5 were characterized by N2 adsorption, powder X-ray
diffraction, Raman spectroscopy, transmission electron microscopy, high-resolution transmission electron
microscopy (HRTEM), and thermogravimetric analysis. It was found that the ferrocene could be used as a
new precursor to prepare CMK-5 nanopipes, with pipe thicknesses varying from 0.8 to 2.6 nm, by increasing
the 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 the
resulting CMK-5 was investigated by pyrolyzing the corresponding silica/carbon composite at different
temperatures. Pyrolysis temperatures below 850 C led to gradually improved graphitization degrees of CMK-5
nanopipes. Pyrolysis temperatures above 850 C resulted in the partial collapse of ordered CMK-5 nanopipes
accompanied by the appearance of a considerable amount of entangled graphitic ribbons. The structural
evolution process of CMK-5 from ordered nanopipes to the final entangled graphitic ribbons was observed
by HRTEM. The obtained CMK-5 was applied as a catalyst support of Pt for methanol oxidation. The
electrochemical activities of Pt nanoparticles loaded on the CMK-5 carbon materials were investigated by
cyclic voltammograms and compared with the commercial Pt/Vulcan XC-72 catalyst. It was found that the
specific mass activity of Pt/CMK-5 was much higher than Pt/Vulcan XC-72.
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