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The Effect of N2O, Catalyst, and Means of Water Vapor Removal on the Graphitization of Small CO2 Samples

Published online by Cambridge University Press:  18 July 2016

A M Smith
Affiliation:
Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, New South Wales 2234, Australia
Vasilii V Petrenko
Affiliation:
Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92037, USA
Quan Hua
Affiliation:
Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, New South Wales 2234, Australia
John Southon
Affiliation:
Earth System Science Department, University of California Irvine, Irvine, California 92697, USA
Gordon Brailsford
Affiliation:
National Institute of Water and Atmospheric Research (NIWA), Wellington, New Zealand
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Abstract

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The effect of nitrous oxide (N2O) upon the graphitization of small (∼40 μg of carbon) CO2 samples at the ANSTO and University of California, Irvine, radiocarbon laboratories was investigated. Both laboratories produce graphite samples by reduction of CO2 over a heated iron catalyst in the presence of an excess of H2. Although there are significant differences between the methods employed at each laboratory, it was found that N2O has no effect upon the reaction at levels of up to 9.3% by volume of CO2. Further, it was systematically determined that more effective water vapor trapping resulted in faster reaction rates. Using larger amounts of the Fe catalyst generally resulted in higher yields or reaction rates (but not both). The effects of changing the type of Fe catalyst on the final yield and reaction rate were less clear.

Type
Articles
Copyright
Copyright © 2007 by the Arizona Board of Regents on behalf of the University of Arizona 

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