1. Selective CO2 Trapping in Guest-Free Hydroquinone Clathrate Prepared by Gas-Phase Synthesis
- Author
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Kyu Won Han, Ji-Ho Yoon, Taro Kawamura, Yun Je Lee, Yoshitaka Yamamoto, Yongjae Lee, Tae-In Jeon, Jong Won Lee, Jin Seok Jang, Thomas Vogt, Takeshi Sugahara, and Jeasung Park
- Subjects
Hydrogen ,Clathrate hydrate ,chemistry.chemical_element ,Microporous material ,Atomic and Molecular Physics, and Optics ,Water-gas shift reaction ,Methane ,Steam reforming ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Organic chemistry ,Physical and Theoretical Chemistry ,Selectivity ,Syngas - Abstract
The most important process to make hydrogen is based on steam reforming of natural gas according to an overall reaction CH4 + 2H2O!4H2 + CO2, where after reformation of the natural gas to a CO/H2 mixture (syngas) a water-gas shift reaction results in a predominantly CO2/H2 mixture. [1, 2] Steam reforming potentially offers one technological path to extend the trend of decarbonization of the primary fossil fuel by taking advantage of the low 1:4 carbon-to-hydrogen ratio of methane compared to coal (~ 8:4) and oil (~ 2:4), provided that subsequent separation of the CO2/H2 mixture and sequestration of CO2 is cost-effective and feasible. We present here a guest-free hydroquinone (HQ) clathrate, prepared by gas-phase synthesis, which reveals unique selectivities towards CO2/CH4 and CO2/H2 mixtures. A dynamical pore-widening process allows CO2 to be adsorbed with a selectivity of 29:1 from a CO2/CH4 (50:50 v/v) mixture and with a selectivity of 60:1 reversibly stored at 7 MPa and 298 K in the presence of a CO2/H2 (50:50 v/v) mixture. This first example of a flexible hydrogen-bonded organic framework (HOF) that can reversibly and selectively absorb and store CO2 opens up a host of applications. The synthesis of microporous materials with cage-like structures, such as zeolites, clathrates and supramolecular com
- Published
- 2011