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Gas-phase production of single-walled carbon nanotubes from carbon monoxide: a review of the hipco processThe latest process for producing large quantities of single-walled carbon nanotubes (SWNTs) to emerge from the Rice University, dubbed HiPco, is living up to its promise. The current production rates approach 450 mg/h (or 10 g/day), and nanotubes typically have no more than 7 mol % of iron impurities. Second-generation HiPco apparatus can run continuously for 7-10 days at a time. In the HiPco process nanotubes grow in high-pressure, high-temperature flowing CO on catalytic clusters of iron. Catalyst is formed in situ by thermal decomposition of iron pentacarbonyl, which is delivered intact within a cold CO flow and then rapidly mixed with hot CO in the reaction zone. Upon heating, the Fe(CO)5 decomposes into atoms that condense into larger clusters. SWNTs nucleate and grow on these particles in the gas phase via CO disproportionation: CO + CO --> CO2 + C (SWNT), catalyzed by the Fe surface. The concentration of CO2 produced in this reaction is equal to that of carbon and can therefore serve as a useful real-time feedback parameter. It was used to study and optimize SWNT production as a function of temperature, pressure, and Fe(CO)5 concentration. The results of the parametric study are in agreement with current understanding of the nanotube formation mechanism.
Document ID
20050151418
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Nikolaev, Pavel
(NASA Johnson Space Center Houston, TX United States)
Date Acquired
August 23, 2013
Publication Date
April 1, 2004
Publication Information
Publication: Journal of nanoscience and nanotechnology
Volume: 4
Issue: 4
ISSN: 1533-4880
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
Review
Review, Tutorial

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