Figure 4. View of the gas adsorption data.

(a) Comparison of the CO₂ adsorption isotherms for MFM-300(V^III) and MFM-300(V^IV) at 273 and 298 K and 1.0 bar. (b) Variation of isosteric heat of adsorption Q_st as a function of CO₂ uptake for MFM-300(V^III) and MFM-300(V^IV) calculated using the van't Hoff isochore on CO₂ adsorption isotherms measured at 273–303 K. Standard deviations are represented by error bars. (c) Comparison of the pore size distribution plots for MFM-300(V^III) and MFM-300(V^IV), suggesting a slightly wider pore size in the latter material. (d) Comparison of the CO₂ adsorption isotherms for MFM-300(V^III) and MFM-300(V^IV) at 273 K up to 20 bar.