Capturing carbon dioxide before it is released into the atmosphere is one promising approach to fighting global warming. A commonly used technology is “amine scrubbing”, trapping the CO₂ of a coal plant’s flue gas by passing it through solutions containing amines. These methods are problematic because of the toxicity and high corrosiveness of the amines.

Emmanuel P. Gianellis and colleagues, Cornell University, Ithaca, NY, USA, have developed a low-toxicity, highly effective solid amine sorbent. Tethering polymerized amines to a mesoporous, sponge-like silica support minimizes the containment and toxicity problems associated with the use of liquid amines. The synthesis of the sorbent involved functionalizing the silica with alkyliodines as initiators and subsequent cationic polymerization of 2-methyl-2-oxazoline, leading to a polyethyleneimine-covered silica surface.

The resulting sorbent shows a high efficiency for carbon dioxide capture and a high capacity of roughly 12 mmol/g under simulated flue gas conditions. This approach may provide routes to new amine-functionalized materials.

• Sponges with covalently tethered amines for high-efficiency carbon capture,
  Genggeng Qi, Liling Fu, Emmanuel P. Giannelis,
  Nat. Commun. 2014.
  DOI: 10.1038/ncomms6796