TITLE:
Adsorption of CO2 on Polyethyleneimine 10k—Mesoporous silica Sorbent: XPS and TGA Studies
AUTHORS:
M. M. Khader, M. J. Al-Marri, Sardar Ali, G. Qi, E. P. Giannelis
KEYWORDS:
XPS, Adsorption Isotherm of CO2, Polyethyleneimine 10k, Mesoporous silica
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.6 No.4,
March
6,
2015
ABSTRACT: A CO2 solid sorbent based on polyethyleneimine 10k (PEI-10k) impregnated into mesoporous silica (MPS) foam was synthesized and utilized to
capture CO2 at temperatures ranged from 65°C to 95°C. The calculated nitrogen and carbon contents in the bulk of the
PEI-10k/MPS sorbent were similar to the XPS results measured on the surface of
the foam, suggesting that the PEI was homo-geneously distributed throughout
the MPS support. After CO2 adsorptionthe N 1s peak was broadened
and could be resolved into two components: a high binding energy component
(~401 eV) and a lower binding energy one (396 eV), respectively. The former
nitrogen states are consistent with a protonated amine, presumably, due to
carbamate formation. The lower binding energy component (~396 eV) could
possibly be due to strongly chemisorbed CO2. The maximum sorption
capacity was about 4 mmole CO2/g sorbent at 85°C and 1 bar. This capacity was doubled by raising the
CO2 pressure to 24.95 bars. The adsorption results can be described
by a Langmuir adsorption isotherm.