Thermal Stability Enhanced Tetraethylenepentamine/Silica Adsorbents for High Performance CO₂ Capture

다국어 초록 (Multilingual Abstract)

<P>Tetraethylenepentamine (TEPA), consisting mainly of primary and secondary amines, exhibits a high CO<SUB>2</SUB> sorption capacity; however, its poor thermal stability hampers practical utilization in the temperature swing adsorption process for CO<SUB>2</SUB> capture. Here, a facile functionalization of TEPA with 1,2-epoxybutane (EB) substantially enhanced its thermal stability as well as the CO<SUB>2</SUB> adsorption kinetics. Our careful analysis on the liquid-state <SUP>13</SUP>C NMR disclosed the amine state distribution of EB-functionalized TEPA (EB-TEPA). Although the increase in tertiary amine portion induced by EB-functionalization reduced CO<SUB>2</SUB> sorption capacity, the 0.64EB-TEPA (i.e., TEPA functionalized with EB with a TEPA/EB molar ratio of 1:3)/SiO<SUB>2</SUB> showed an excellent long-term stability over the 10 consecutive cycles of adsorption/desorption processes with a CO<SUB>2</SUB> swing capacity of 2.0 mmol CO<SUB>2</SUB> g<SUP>-1</SUP> under dry CO<SUB>2</SUB>/N<SUB>2</SUB> (15/85 mol/mol) feed conditions. Also, the first-principles calculation identified the configuration of modified TEPA molecules with XRD measurements, supporting an easy access of CO<SUB>2</SUB> into amine moieties of our modified TEPA molecules.</P>
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