Strategies to Enhance Carbon Dioxide Capture in Metal-Organic Frameworks.

The dramatic increase of atmospheric CO 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 CO DAC and achieve unprecedented performances. Herein strategies to improve the CO 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 CO 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 CO capture performances. Another approach involves the synthesis of amine-functionalized MOFs that can chemically bind carbon dioxide.