Deep eutectic solvents as both precursors and structure directing agents in the synthesis of nitrogen doped hierarchical carbons highly suitable for CO2 capture
- 21 July 2011
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Energy & Environmental Science
- Vol. 4 (9), 3535-3544
- https://doi.org/10.1039/c1ee01463c
Abstract
Deep eutectic solvents (DESs) have been used in the synthesis of nitrogen-doped carbons exhibiting a hierarchical porous structure. The CO2 sorption capacity of these solid sorbents was extraordinary because of their relatively high nitrogen content and their bimodal porous structure where micropores provide high surface areas (ca. 700 m2 g−1) and macropores provide accessibility to such a surface. DESs were composed of resorcinol, 3-hydroxypyridine and choline chloride in 2 : 2 : 1 and 1 : 1 : 1 molar ratios. Polycondensation of resorcinol and 3-hydroxypyridine (with formaldehyde) promoted DES segregation in a spinodal-like decomposition process by the formation of a polymer rich phase and a depleted polymer phase. Thus, DESs played a multiple role in the synthetic process; the liquid medium that ensured reagents homogenization, the structure-directing agent that is responsible for the achievement of the hierarchical structure, and the source of carbon and nitrogen of the solid sorbent obtained after carbonization. Interestingly, the homogeneous incorporation of nitrogen at the solution stage of the synthetic process (rather than by post-treatment of the preformed carbon) allowed the achievement of significant nitrogen contents even in carbons obtained at relatively high temperatures (e.g. 8–12 at% for 600 °C and ca. 5 at% for 800 °C). It is worth noting that, despite thermal treatments at high temperatures tend to decrease the nitrogen content, the high surface area of the solid sorbents obtained at 800 °C contributed to a significant enhancement of CO2 capture while providing superior selectivity, recyclability and stability.Keywords
This publication has 56 references indexed in Scilit:
- Sustainable porous carbons with a superior performance for CO2 captureEnergy & Environmental Science, 2011
- Phloroglucinol Based Microporous Polymeric Organic Frameworks with −OH Functional Groups and High CO2 Capture CapacityChemistry of Materials, 2011
- Hypercrosslinked organic polymer networks as potential adsorbents for pre-combustion CO2 captureJournal of Materials Chemistry, 2011
- High‐Surface‐Area Carbon Molecular Sieves for Selective CO2 AdsorptionChemSusChem, 2010
- Fluidic Carbon Precursors for Formation of Functional Carbon under Ambient Pressure Based on Ionic LiquidsAdvanced Materials, 2010
- A novel thermal degradation mechanism of phenol–formaldehyde type resinsThermochimica Acta, 2008
- High-Throughput Synthesis of Zeolitic Imidazolate Frameworks and Application to CO 2 CaptureScience, 2008
- Time-Efficient Acid-Catalyzed Synthesis of Resorcinol−Formaldehyde AerogelsChemistry of Materials, 2007
- Nuclear Magnetic Resonance Studies of Resorcinol−Formaldehyde AerogelsThe Journal of Physical Chemistry B, 2005
- An Isotherm Equation for Adsorption to High Pressures in Microporous AdsorbentsLangmuir, 1996