Strategies to Enhance Carbon Dioxide Capture in Metal-Organic Frameworks

The dramatic increase of atmospheric CO₂ concentration is responsible for a fast and potentially unpredictable global climate change. Therefore, the implementation of negative carbon technologies such as direct air capture (DAC) is needed. Metal-organic frameworks (MOFs) have the potential to perform CO₂ DAC and achieve unprecedented performances. Herein strategies to improve the CO₂ capture efficiency of MOFs and their potential implementation in real applications are discussed. Three main categories of targeted modifications to the frameworks are usually performed to enhance the CO₂ uptake capacity and adsorption selectivity: 1) modifications to the metal unit; 2) modifications to the linker unit; 3) confinement of solvents within MOFs. The synthesis of MOF composites using other porous materials as support is also a useful method to improve the CO₂ capture performances. Another approach involves the synthesis of amine-functionalized MOFs that can chemically bind carbon dioxide.