Work

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 Particles within an α-Al1.8Fe0.2O3 Self-Supported Foam

Year: 2010

Type: article

Abstract: α-Al 1.8 Fe 0.2 O 3 and α-Al 1.8 Fe 0.2 O 3 −MoO 3 self-supported foams are used as catalytic materials for the synthesis of carbon nanotubes by catalytic chemical vapor deposition. A MoO 3 -supported conditioning catalyst placed upstream in the reactor is more efficient than MoO 3 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 H 2 O formed by the H 2 reduction of MoO 3 and, therefore, lower H 2 and CH 4 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 MoO 3 -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.

Source: The Journal of Physical Chemistry C

DOI: 10.1021/jp105712q

Authors: Anne Cordier, Valdirene G. de Resende, Alicia Weibel, Eddy De Grave, Alain Peigney, Christophe Laurent