From Azo-Linked Polymers to Microporous Heteroatom-Doped Carbons: Tailored Chemical and Textural Properties for Gas Separation

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• 作者：Babak Ashourirad ; Pezhman Arab ; Alyson Verlander ; Hani M. El-Kaderi
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：April 6, 2016
• 年：2016
• 卷：8
• 期：13
• 页码：8491-8501
• 全文大小：673K
• ISSN：1944-8252

文摘

Heteroatom-doped porous carbons with ultrahigh microporosity were prepared from a nitrogen-rich azo-linked polymer (ALP-6) as a precursor for gas separation applications. Direct carbonization and chemical activation of ALP-6 with ZnCl₂ and KOH were successfully applied to obtain three different classes of porous carbons (ALPDCs). Synthetic processes were conducted at relatively mild temperatures (500–800 °C),which resulted in retention of appreciable levels of nitrogen content (4.7–14.3 wt %). Additionally, oxygen functionalities were found to be present in chemically activated samples. The resultant porous carbons feature a diverse range of textural properties with a predominant microporous nature in common. The highest CO₂ uptake value of 5.2 mmol g^–1 at 1 bar and 298 K in ALPDCK600 was originated from well-developed porosity and basic heteroatoms (N and O) on the pore walls. The highest heteroatom doping level (12 wt % nitrogen and 20 wt % oxygen) coupled with the high level of microporosity (84%) for ALPDCK500 led to notable CO₂/N₂ (62) and CO₂/CH₄ (11) selectivity values and a high CO₂ uptake capacity (1.5 mmol g^–1, at 0.15 bar) at 298 K. This study illustrates the effective use of a single-source precursor with robust nitrogen bonds in combination with diverse carbonization methods to tailor the chemical and textural properties of heteroatom-doped porous carbons for CO₂ capture and separation applications.