Hydration Energetics of a Diamine-Appended Metal–Organic Framework Carbon Capture Sorbent
Makaleler > Tam Makale · 2019
Yazarlar: Jun Wang, Esra Yılmaz, Xianghui Zhang, Houqian Li, Renqin Zhang, Xiaofeng Guo, Hui Sun, Baodong Wang, Di Wu
The Journal of Physical Chemistry C, Uluslararası, Wos, 2019, cilt 124, ss 398-403
Özet
mmen-Mg 2 (dobpdc) (mmen = N, N ′-dimethylethylenediamine, dobpdc = 4,4′-dioxidobiphenyl-3,3′-dicarboxylate) is a diamine-appended metal–organic framework (MOF) material with promising future as an efficient CO 2 capture sorbent for industry applications. Here, using adsorption calorimetry, the energetic landscape of mmen-Mg 2 (dobpdc) hydration has been revealed. Specifically, at near-zero water coverage, hydration results in the most exothermic differential enthalpy of adsorption of −110.9 ± 3.1 kJ/mol water. A differential enthalpy plateau at −65.8 ± 4.7 kJ/mol water is observed at the intermediate degree of hydration, which corresponds to water–diamine chemisorption through hydrogen bonding. Eventually, mmen-Mg 2 (dobpdc) hydration is concluded at the second differential enthalpy plateau at −44.2 ± 1.8 kJ/mol water suggesting condensation of water within the internal channel space of mmen-Mg 2 (dobpdc). The position of the second plateau at about −44.0 kJ/mol water strongly suggests formation of liquid-like water clusters within the hydrophilic nanoconfinement environment. This comprehensive study energetically distinguishes the guest–host interfacial bonding and guest–guest intermolecular interactions for the water–mmen-Mg 2 (dobpdc) system, which provides fundamental thermodynamic data to enhance our understanding of the behavior of CO 2 capture sorbents in the presence of moisture.