Catalytic Chemical Vapor Deposition Synthesis of Double-Walled and Few-Walled Carbon Nanotubes by Using a MoO3-Supported Conditioning Catalyst to Control the Formation of Iron Catalytic Par

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• 作者：Anne Cordier ; Valdirene G. de Resende ; Alicia Weibel ; Eddy De Grave ; Alain Peigney ; Christophe Laurent
• 刊名：Journal of Physical Chemistry C
• 出版年：2010
• 出版时间：November 18, 2010
• 年：2010
• 卷：114
• 期：45
• 页码：19188-19193
• 全文大小：308K
• 年卷期：v.114,no.45(November 18, 2010)
• ISSN：1932-7455

文摘

α-Al_1.8Fe_0.2O₃ and α-Al_1.8Fe_0.2O₃−MoO₃ self-supported foams are used as catalytic materials for the synthesis of carbon nanotubes by catalytic chemical vapor deposition. A MoO₃-supported conditioning catalyst placed upstream in the reactor is more efficient than MoO₃ present within the catalytic material in producing double-walled and few-walled carbon nanotubes with fewer defects. It is shown that the corresponding modifications of the gas atmosphere (presence of H₂O formed by the H₂ reduction of MoO₃ and, therefore, lower H₂ and CH₄ concentrations) allow one to limit more efficiently the release of the Fe catalyst from the oxide solid-solution foam, which results in the formation of fewer Fe nanoparticles, which, therefore, are less prone to undesirable growth. Thus, a MoO₃-induced “solid-state” effect is demonstrated within the catalytic material without molybdenum species being themselves present within this material. This could lead to simplifications in the design of catalytic materials.