Among various ways to reduce CO₂ emission, replacing gasoline with cleaner energy sources, such as natural gas, is highly sought-after. However, since natural gas contains 10−20 mol % CO₂ when extracted, the removal of CO₂ has, therefore, become a prerequisite for effective utilization of natural gas.

To serve this purpose, James M. Tour at Rice University, Houston, Texas, USA, and colleagues have synthesized sulfur- and nitrogen containing porous carbons from inexpensive thiophene- and acrylonitrile-based polymers, respectively. These nucleophilic materials can chemically adsorb CO₂ from natural gas with a capacity up to 82 wt % of sorbent at 30 bar through a hetero atom-initiated CO₂ polymerization mechanism.

With excellent selectivity towards CO₂, the novel carbon materials require much lower pressure to capture CO₂ than existing ones. Furthermore, they can be reinstated upon spontaneous release of CO₂ under ambient conditions, without the need for any thermal energy input. All these advantages make them ideal candidates for not only cleaning natural gas, but also CO₂ sequestration, among other applications.

• Capturing carbon dioxide as a polymer from natural gas,
  C.-C. Hwang, J. J. Tour, C. Kittrell, L. Espinal, L. B. Alemany, J. M. Tour,
  Nature Communic. 2014, 5.
  DOI: 10.1038/ncomms4961