Capturing the Local Adsorption Structures of Carbon Dioxide in Polyamine-Impregnated Mesoporous Silica Adsorbents.
Interactions between amines and carbon dioxide (CO2) are essential to amine-functionalized solid adsorbents for carbon capture, and an in-depth knowledge of these interactions is crucial to adsorbent design and fabrication as well as adsorption/desorption processes. The local structures of CO2 adsorbed on a tetraethylenepentamine-impregnated mesoporous silica SBA-15 were investigated by solid-state (13)C{(14)N} S-RESPDOR MAS NMR technique and theoretical DFT calculations. Two types of adsorption species, namely, secondary and tertiary carbamates as well as distant ammonium groups were identified together with their relative concentrations and relevant (14)N quadrupolar parameters. Moreover, a dipolar coupling of 716 Hz was derived, corresponding to a (13)C-(14)N internuclear distance of 1.45 Å. These experimental data are in excellent agreement with results obtained from DFT calculations, revealing that the distribution of surface primary and secondary amines readily dictates the CO2 adsorption/desorption properties of the adsorbent.
†Instrumentation Center, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
Shing-Jong
SJ
Huang
§Institute of Atomic and Molecular Sciences, Academia Sinica, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
Chin-Te
CT
Hung
∥State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, West No. 30 Xiao Hong Shan, Wuhan 430071, China.
Anmin
A
Zheng
§Institute of Atomic and Molecular Sciences, Academia Sinica, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.|⊥Department of Chemical and Materials Engineering, Tamkang University, 151, Yingzhuan Road, New Taipei City 25137, Taiwan.
Jen-Shan
JS
Lin
§Institute of Atomic and Molecular Sciences, Academia Sinica, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.|⊥Department of Chemical and Materials Engineering, Tamkang University, 151, Yingzhuan Road, New Taipei City 25137, Taiwan.
Chun-Fei
CF
Yang
⊥Department of Chemical and Materials Engineering, Tamkang University, 151, Yingzhuan Road, New Taipei City 25137, Taiwan.
Yu-Chi
YC
Chang
∥State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, West No. 30 Xiao Hong Shan, Wuhan 430071, China.
Feng
F
Deng
§Institute of Atomic and Molecular Sciences, Academia Sinica, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.|‡Department of Chemistry, National Taiwan Normal University, 88, Sec. 4, Ting-Chow Road, Taipei 11677, Taiwan.
Shang-Bin
SB
Liu
DFT calculation; adsorption; amine-impregnated mesoporous silica; amine−CO2 interaction; carbon dioxide capture; solid-state NMR