查看文章

A new diamine-functionalized metal–organic framework comprised of 2,2-dimethyl-1,3-diaminopropane (dmpn) appended to the Mg²⁺ sites lining the channels of Mg₂(dobpdc) (dobpdc^4– = 4,4′-dioxidobiphenyl-3,3′-dicarboxylate) is characterized for the removal of CO₂ from the flue gas emissions of coal-fired power plants. Unique to members of this promising class of adsorbents, dmpn–Mg₂(dobpdc) displays facile step-shaped adsorption of CO₂ from coal flue gas at 40 °C and near complete CO₂ desorption upon heating to 100 °C, enabling a high CO₂ working capacity (2.42 mmol/g, 9.1 wt %) with a modest 60 °C temperature swing. Evaluation of the thermodynamic parameters of adsorption for dmpn–Mg₂(dobpdc) suggests that the narrow temperature swing of its CO₂ adsorption steps is due to the high magnitude of its differential enthalpy of adsorption (Δh_ads = −73 ± 1 kJ/mol), with a larger than expected …