Effect of Solvent Assisted Linker Exchange (SALE) and De Novo Synthetic Routes on CO2 Uptake and Fixation by Mixed-Linker Zeolitic Imidazolate Frameworks

Abstract

Direct mixing (de novo) and Solvent Assisted Ligand Exchange (SALE) are the main methods used for the synthesis of Mixed-Linker Zeolitic Imidazolate Frameworks (ML-ZIFs). ML-ZIFs with combined –NO2 and –Br/–Cl functionalities were prepared via both synthetic routes. Thereafter the CO2 uptake of the ML-ZIFs were compared, as well as their abilities to fixate CO2 with epoxide substrates. The de novo synthesis resulted in ML-ZIFs with SOD topologies, 60: 40 (–NO2: –Br/–Cl) functionality ratios, higher porosities, better thermal stability and higher CO2 uptake than equivalent SALE products.