Highly CO selective Cu(I)-doped MIL-100(Fe) adsorbent with high CO/CO2 selectivity due to π complexation: Effects of Cu(I) loading and activation temperature

Mg2+ embedded MIL‐101(Cr)‐NH2 framework for improved CO2 adsorption and CO2/N2 selectivity

“…This could be due to the interaction between Mg 2+ species and the benzene group of the linker via the electrostatic force, weakening vibrations of the benzene groups on MOF. [30,31] Figure 5 shows TGA analyses of the prepared MIL-101(Cr)-NH2 and Mg-incorporated MOF samples. As shown in figure 5, the TGA curve of the pristine MIL-101(Cr)-NH2 shows three weight loss stages.…”

Optimisation of Cu+ impregnation of MOF-74 to improve CO/N2 and CO/CO2 separations

“…Initially, we synthesized Cu@Ni-MOF-74 samples using CuCl 2 and Cu(HCO 2 ) 2 as Cu precursors and used the results to optimise the Cu loading. We selected CuCl 2 , a commonly used precursor, 17,18,[21][22][23] because of its ability to be reduced to CuCl leading to strong Cu + -CO p-complexation. Cu(HCO 2 ) 2 was chosen due to its ability to simultaneously provide a reducing agent and a Cu + source.…”

“…Cu impregnation replaced the accessibility of Ni 2+ open-metal sites for CO and CO 2 binding with Cu + openmetal sites solely for CO binding. CO/N 2 and CO/CO 2 separation performance was also improved aer Cu impregnation of Fe-MIL-100 and Cr-MIL-101, [21][22][23][24][25][26] but was improved to a smaller degree with M-MOF-74 because of the highly active Ni 2+ sites compared to Fe 3+ and Cr 3+ .…”

“…Previous studies have tested the cyclability of Ni-MOF-74 (ref. 6) and Cu impregnated MOFs for CO purication, 22,23,25 with He purging 22 and vacuum swing 25 regeneration techniques favoured to minimise any potential overreduction which would be associated with thermal regeneration. Yet, vacuum swing and He purging would not regenerate the Ni 2+ sites of the MOF.…”

“…Cu + metal sites have been incorporated on Fe-MIL-100 for CO/N 2 via impregnation with Cu 2+ -based salts followed by reduction to Cu + . 21 The same method has also been employed on Fe-MIL-100 for CO/CO 2 separation, [22][23][24] and on MIL-101 for CO/N 2 separation. 25 The CuAlCl 4 complex used in the COSORB process 3 has been loaded onto Cr-MIL-101 to improve CO/N 2 separation and Cu + stability.…”