Figure 8.

Plot of the differential enthalpy (−Δh_ads) vs. differential entropy (−Δs_ads) of CO₂ adsorption for alkylethylenediamine-appended Mg₂(dobpdc) frameworks, as calculated using a Clausius–Clapeyron relationship at a loading of 1 mmol/g (within the first step of the cooperative adsorption region) for isotherms over a range of 25 to 120 °C. A linear relationship is apparent (black line, R² = 0.97), demonstrating enthalpy–entropy compensation for cooperative CO₂ adsorption in this class of materials. Materials above the dashed gray line are predicted to be capable of capturing 90% of the CO₂ from a coal flue gas stream (15% CO₂ in N₂ at 40 °C).