Unravelling gas sorption in the aluminum metal‐organic framework CAU‐23: CO ₂ , H ₂ , CH ₄ , SO ₂ sorption isotherms, enthalpy of adsorption and mixed‐adsorptive calculations

The report is the first broader evaluation of gas sorption properties CAU-23 for adsorptives CO2, H2, CH4, and SO2. intermediate porosity among Al-MOFs with specific BET surface areas order MIL-100>MIL-53>CAU-23>MIL-160>MIL-53-TDC>Alfum>CAU-10-H total pore volumes MIL-100>MIL-53>CAU-23>Alfum=MIL-160>MIL-53-TDC>CAU-10-H. CO2 uptake (3.97 mmol g−1, 293 K) H2 (10.25 77 are second in series only slightly smaller than MIL-160. CH4 (0.89 unremarkable comparison other Al-MOFs. SO2 (8.4 follows higher uptakes were observed MIL-53 MIL-100. one best high-pressure an 33 wt.-% at 20 bar, K. Gas measurements two different temperatures gave near zero-coverage enthalpy adsorptions, ▵Hads0 −22 kJ mol−1 −38 which low end (−22 to −39 CO2; −41 −51 SO2), yet ▵Hads increases −25 −57 mol−1, respectively. For CO2/CH4 SO2/CO2 separation, ideal adsorbed solution theory (IAST) predicted selectivities 5 27–50 (depending on molar ratio model), respectively, line 4.5–6.3 17–50, most Al-MOFs, where MIL-53-TDC 83 MIL-160 126 a selectivity 0.5.