Shaping of ultrahigh-loading MOF pellet with a strongly anti-tearing binder for gas separation and storage

Four anion-pillared ultramicroporous powder (SIFSIX-3-Ni, SIFSIX-2-Cu-i, GEFSIX-2-Cu-i, TIFSIX-2-Cu-i) were shaped into pellets for the first time, using a strongly anti-tearing and highly sticky binder-polyvinyl butyral (PVB). PVB binder exhibited good compatibility and interaction with MOFs, which afforded the ultrahigh-loading of MOFs (up to 95%). Interestingly, this shaping method showed slight influence to the adsorption capacity of C2H2 (decreased by 0.56%-0.93%), while greatly hindered the adsorption of C2H4 (decreased by 5.0%-12.5%). These different influences resulted in the enhanced IAST selectivity (116.4) of GeFSIX-2-Cu-i pellet for the separation of C2H2/C2H4 (1: 99, v/v), which was 35% larger than the pure GeFSIX-2-Cu-i powder (86.3). Fixed-bed breakthrough experiments showed that SIFSIX-3-Ni pellets achieved the effective separation of C2H2/C2H4 (1: 99, v/v) mixtures. Furthermore, SO2 adsorption of SIFSIX-3-Ni pellets and GeFSIX-2-Cu-i pellets were obtained at 2000 ppm and 298 K. Remarkably, GeFSIX-2-Cu-i pellet had an excellent capacity of SO2 (95%-loading: 2.25 mmol g(-1); 90%-loading: 1.96 mmol g(-1)) at such a low pressure. Additionally, this approach was applied to other three typical MOFs HKUST-1, Mg-MOF-74, and MIL-101-Cr for CO2 capture. It revealed that the PVB binder was applicable to diverse MOFs for pelletization.