In
Situ Observation of Carbon Dioxide Capture on Pseudo-Liquid Eutectic
Mixture-Promoted Magnesium Oxide
Hanyeong Lee
Monica Louise T. Triviño
Soonha Hwang
Sung Hyun Kwon
Seung Geol Lee
Jun Hyuk Moon
Jungho Yoo
Jeong Gil Seo
10.1021/acsami.7b14256.s002
https://acs.figshare.com/articles/media/In_Situ_Observation_of_Carbon_Dioxide_Capture_on_Pseudo-Liquid_Eutectic_Mixture-Promoted_Magnesium_Oxide/5768238
Eutectic
mixtures of alkali nitrates are known to increase the sorption capacity
and kinetics of MgO-based sorbents. Underlying principles and mechanisms
for CO<sub>2</sub> capture on such sorbents have already been established;
however, real-time observation of the system was not yet accomplished.
In this work, we present the direct-observation of the CO<sub>2</sub> capture phenomenon on a KNO<sub>3</sub>–LiNO<sub>3</sub> eutectic
mixture (EM)-promoted MgO sample, denoted as KLM, via in situ transmission
electron microscopy (in situ TEM). Results revealed that the pseudoliquid
EM undergoes structural rearrangement as MgCO<sub>3</sub> evolves
from the surface of MgO, resulting in surface roughening and evolution
of cloudy structures that stay finely distributed after regeneration.
From this, we propose a nucleation and structural rearrangement scheme
for MgCO<sub>3</sub> and EM, which involves the rearrangement of bulk
EM to evenly distributed EM clusters due to MgCO<sub>3</sub> saturation
as adsorption proceeds. We also conducted studies on the interface
between EM over solid MgO and MgCO<sub>3</sub> formed during sorption,
which further clarifies the interaction between MgO and EM. This study
provides better insight into the sorption and regeneration mechanism,
as well as the structural rearrangements involved in EM-promoted sorbents
by basing not only on intrinsic evolutions but also on real-time
observation of the system as a whole.
2017-12-26 00:00:00
Carbon Dioxide Capture
MgO
TEM
MgCO 3
sorption
MgCO 3 saturation
Pseudo-Liquid Eutectic Mixture-Promoted Magnesium Oxide Eutectic mixtures
EM
KNO
KLM
transmission electron microscopy
CO 2
sorbent
rearrangement