Highly Selective and Stable Carbon Dioxide Uptake in Polyindole-Derived Microporous Carbon Materials

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• 作者：Muhammad Saleh ; Jitendra N. Tiwari ; K. Christain Kemp ; Muhammad Yousuf ; Kwang S. Kim
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：May 21, 2013
• 年：2013
• 卷：47
• 期：10
• 页码：5467-5473
• 全文大小：468K
• 年卷期：v.47,no.10(May 21, 2013)
• ISSN：1520-5851

文摘

Adsorption with solid sorbents is considered to be one of the most promising methods for the capture of carbon dioxide (CO₂) from power plant flue gases. In this study, microporous carbon materials used for CO₂ capture were synthesized by the chemical activation of polyindole nanofibers (PIF) at temperatures from 500 to 800 掳C using KOH, which resulted in nitrogen (N)-doped carbon materials. The N-doped carbon materials were found to be microporous with an optimal adsorption pore size for CO₂ of 0.6 nm and a maximum (Brunauer鈥揈mmett鈥揟eller) BET surface area of 1185 m² g^鈥?. The PIF activated at 600 掳C (PIF6) has a surface area of 527 m² g^鈥? and a maximum CO₂ storage capacity of 3.2 mmol g^鈥? at 25 掳C and 1 bar. This high CO₂ uptake is attributed to its highly microporous character and optimum N content. Additionally, PIF6 material displays a high CO₂ uptake at low pressure (1.81 mmol g^鈥? at 0.2 bar and 25 掳C), which is the best low pressure CO₂ uptake reported for carbon-based materials. The adsorption capacity of this material remained remarkably stable even after 10 cycles. The isosteric heat of adsorption was calculated to be in the range of 42.7鈥?4.1 kJ mol^鈥?. Besides the excellent CO₂ uptake and stability, PIF6 also exhibits high selectivity values for CO₂ over N₂, CH₄, and H₂ of 58.9, 12.3, and 101.1 at 25 掳C, respectively, and these values are significantly higher than reported values.