Edge-Functionalized Graphene Nanoribbon Frameworks for the Capture and Separation of Greenhouse Gases

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• 作者：Yearin Byun ; Moses Cho ; Daeok Kim ; Yousung Jung ; Ali Coskun
• 刊名：Macromolecules
• 出版年：2017
• 出版时间：January 24, 2017
• 年：2017
• 卷：50
• 期：2
• 页码：523-533
• 全文大小：687K
• ISSN：1520-5835

文摘

We demonstrate a bottom-up synthetic approach for the synthesis of graphene nanoribbon frameworks (GNFs) incorporating edge-functionalized graphene nanoribbons via the Diels–Alder cycloaddition polymerization and a subsequent FeCl₃-catalyzed cyclo-dehydrogenation reactions. This approach not only allowed us to precisely position substituents, namely, −OMe (GNF-0), −H (GNF-1), −CF₃ (GNF-2), and −F (GNF-3), but also enabled to tune textural properties and gas affinity of resulting frameworks. GNFs exhibited promising physical properties such as high surface areas (up to 755 m² g^–1) and excellent physicochemical and thermal stabilities (up to 400 °C). Narrow pore size distribution and the presence of large aromatic units led to high affinity toward gases such as CO₂ (27.4–30.9 kJ mol^–1 at 1 bar), CH₄ (21.3–26.0 kJ mol^–1 at 1 bar), and H₂ (6.5–8.2 kJ mol^–1 at 1 bar). Notably, GNFs also showed promising CO₂/CH₄ breakthrough separation performance for natural gas sweetening and landfill gas separations at 298 K. The edge-functionalization of GNFs with −CF₃ and −F significantly improved their affinity toward perfluorocarbons and CFCs, which are classified as potent greenhouse gases. Compared to GNF-3, GNF-2 containing −CF₃ moieties showed much higher uptake capacity toward CFC-113 (67 wt % at 298 K).