Water-Stable etb-MOFs for Methane and Carbon Dioxide Storage

We utilized the etb platform of MOFs for the synthesis of two new water-stable compounds based on amide functionalized trigonal tritopic organic linkers H 3 BTBTB (L1), H 3 BTCTB (L2) and Al 3+ metal ions, namely, Al(L1) and Al(L2) . The mesoporous Al(L1) material exhibits an impressive methane (CH 4 ) uptake at high pressures and ambient temperature. The corresponding values of 192 cm 3 (STP) cm –3, 0.254 g g –1 at 100 bar, and 298 K are among the highest reported for mesoporous MOFs, while the gravimetric and volumetric working capacities (between 80 bar and 5 bar) can be well compared to the best MOFs for CH 4 storage. Furthermore, at 298 K and 50 bar, Al(L1) adsorbs 50 wt % (304 cm 3 (STP) cm –3 ) CO 2, values among the best recorded for CO 2 storage using porous materials. To gain insight into the mechanism accounting for the resultant enhanced CH 4 storage capacity, theoretical calculations were performed, revealing the presence of strong CH 4 adsorption sites near the amide groups. Our work demonstrates that amide functionalized mesoporous etb -MOFs can be valuable for the design of versatile coordination compounds with CH 4 and CO 2 storage capacities comparable to ultra-high surface area microporous MOFs.