Stability of zeolitic imidazolate frameworks (ZIF-7) under high pressures and its implications on storage applications of ZIFs

We report the chemical stability of ZIF-7 under pressure using Raman spectroscopy. Our results show a reversible pressure response of ZIF-7 in non-penetrating media up to 8 GPa. Increasing pressures above 12 GPa leads to an irreversible ring-opening polymerization to a disordered phase. The lower chemical stability of ZIF-7 over prototypic ZIF-8 is explained to be due to hydrogen bonding C-H-pi interaction. This study highlights the role of various substituents in the imidazole linkers in ZIFs for their gas storage applications under pressure.

Automated summary

This study reports on the chemical stability of ZIF-7 under pressure using Raman spectroscopy. The results demonstrate a reversible pressure response of ZIF-7 up to 8 GPa in non-penetrating media. However, increasing pressures above 12 GPa lead to an irreversible ring-opening polymerization and disordered phase. The lower chemical stability of ZIF-7, compared to prototypic ZIF-8, is attributed to the hydrogen bonding C-H-pi interaction. This study highlights the importance of various substituents in the imidazole linkers of ZIFs for gas storage applications under pressure.