In situ infrared study of the role of PEG in stabilizing silica-supported amines for CO(2) capture.

The CO(2) capture capacity, adsorption mechanism, and degradation characteristics of two sorbents, silica-supported tetraethylenepentamine (TEPA/SiO(2)) and polyethylene-glycol-modified TEPA/SiO(2) (PEG/TEPA/SiO(2)), are studied by diffuse reflectance infrared Fourier transform spectroscopy and mass spectrometry. The CO(2) capture capacities of TEPA/SiO(2) and PEG/TEPA/SiO(2) are determined to be 2087 and 1110 micromol CO(2) g(-1) sorbent, respectively. Both sorbents adsorb CO(2) as hydrogen-bonding species, NH(2)--O, and carbamate/carboxylate species.