Reactivity and Porosity of a Carbon Fiber Activated with Supercritical CO2

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• 作者：M. Jesú ; s Sá ; nchez-Montero ; Francisco Salvador ; Carmen Izquierdo
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：April 3, 2008
• 年：2008
• 卷：112
• 期：13
• 页码：4991 - 4999
• 全文大小：504K
• 年卷期：v.112,no.13(April 3, 2008)
• ISSN：1932-7455

文摘

This work describes a comparative study carried out on the reactivity and on the development of the porosityof a carbon fiber when it was gasified with supercritical CO₂ (SCCO₂) and with CO₂ at atmospheric pressure(ATCO₂). The kinetic results show that for the same temperature the rate of gasification of the fiber withSCCO₂ is much higher than when ATCO₂ is used. The kinetic parameters of activation, the activation energyand the preexponential factor, obtained suggest a change in the reaction mechanism when SCCO₂ is used.This change would be favored by the formation of high-density clusters as a result of the increase in pressure,and these would be responsible for the increase in reactivity. Moreover, with both activating agents activatedcarbon fibers (ACFs) were obtained that were fully microporous and had very high surface areas and microporevolumes. Nevertheless, the ACFs prepared with ATCO₂ developed very narrow micropores, while thoseprepared with SCCO₂ developed wider micropores.