Enhanced CO2 adsorption in nano-ZIF-8 modified by solvent assisted ligand exchange

The organic linkers of Zeolitic Imidazole Framework-8 (ZIF-8) nanoparticles influence its adsorption of CO2 gases. Solvent Assisted Ligand Exchange (SALE) was successfully used to exchange similar to 13% of the 2-methylimidazolate linkers of ZIF-8 nanoparticles with 2-mercaptobenzimidazole, 2-aminobenzimidazole or 2-phenylimidazole. With 2-nitroimidiazole similar to 67% exchange was achieved, since no bulky benzyl groups were present During SALE treatment the SOD (sodalite zeolitic framework type) topology of ZIF-8 was maintained, but after the higher exchange percentage of 2-nitroimidazole an frl topology was observed. Up to a two-fold increase in CO2 adsorption was recorded after SALE of ZIF-8 with imidazole derivatives containing NO2 and SH electron withdrawing functional groups. In the case of 2-aininobensimiciazole only a moderate increase in CO2 adsorption was observed.