TY - JOUR
T1 - In-situ XPS studies of CO2 capture by aqueous monoethanolamine (MEA) solutions
AU - Lewis, Tanza
AU - Kahan, Tara
AU - Faubel, Manfred
AU - Winter, Bernd
AU - Hemminger, John C.
PY - 2011/8/25
Y1 - 2011/8/25
N2 - XPS on a micro liquid jet has been used to study solutions of monoethanolamine (MEA), which is commonly used in gas stream scrubbing for carbon dioxide capture. It is likely that interactions between CO2 and the aqueous MEA solution at the gas/liquid interface are important to this process, yet there is little information available concerning the spatial distribution of species at the interface of such solutions. In the present work, aqueous solutions of MEA with a range of pH values as well as solutions of MEA reacted with CO2 have been measured using tunable synchrotron radiation from the BESSY facility in Berlin, where the photoelectron kinetic energy can be varied to obtain depth dependent composition information. N1s photoemission spectra allow for the identification of protonated verses unprotonated MEA by the different binding energies of the two species, and likewise, C1s spectra allow for the determination of CO2-reacted verses unreacted MEA. Depth profiling shows that deprotonated MEA is more surface active than the protonated species and reveals the spatial distribution of CO2-reacted products at the liquid/vapor interface of solution. The mechanism of the reaction of CO2 with aqueous solutions of monoethanolamine will be discussed in light of our results.
AB - XPS on a micro liquid jet has been used to study solutions of monoethanolamine (MEA), which is commonly used in gas stream scrubbing for carbon dioxide capture. It is likely that interactions between CO2 and the aqueous MEA solution at the gas/liquid interface are important to this process, yet there is little information available concerning the spatial distribution of species at the interface of such solutions. In the present work, aqueous solutions of MEA with a range of pH values as well as solutions of MEA reacted with CO2 have been measured using tunable synchrotron radiation from the BESSY facility in Berlin, where the photoelectron kinetic energy can be varied to obtain depth dependent composition information. N1s photoemission spectra allow for the identification of protonated verses unprotonated MEA by the different binding energies of the two species, and likewise, C1s spectra allow for the determination of CO2-reacted verses unreacted MEA. Depth profiling shows that deprotonated MEA is more surface active than the protonated species and reveals the spatial distribution of CO2-reacted products at the liquid/vapor interface of solution. The mechanism of the reaction of CO2 with aqueous solutions of monoethanolamine will be discussed in light of our results.
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M3 - Conference Article
AN - SCOPUS:80051909036
SN - 0065-7727
JO - ACS National Meeting Book of Abstracts
JF - ACS National Meeting Book of Abstracts
T2 - 241st ACS National Meeting and Exposition
Y2 - 27 March 2011 through 31 March 2011
ER -