4 | Conclusions
In summary, pyrazine-interior-embodied MOF-74 composites were prepared
through a post vapor modification process. Owing to the blocking effect
of pyrazine molecules, the composites can significantly widen the
adsorption gaps between CO2 and its counterparts
(CH4 and N2), resulting in lower
saturation uptake for gases albeit with much higher selectivity. We also
underline the stability of pyrazine-interior-embodied MOF-74. Pyrazine
molecules can hardly escape from the composites at its boiling point,
and the composites display higher thermal stability than the parent
framework MOF-74, which is attributed to the chemical insertion of
pyrazine to the open metal ions of MOF-74. The
pyrazine-interior-embodied MOF-74 composites that display significant
CO2 selectivity and moderate adsorption enthalpies would
be good candidates in dynamic adsorption-based separation and membrane
separation.