Metal-organic framework hybrid adsorbents for carbon capture - A review

Metal-organic frameworks (MOFs) are three-dimensional network structures synthesized by the assembly of organic ligands with metal ions or clusters. They currently constitute one of the most promising adsorbent categories for CO2 capture given their high specific surface area and porosity, chemical versatility, and facile chemistry supporting strategic structural modifications. Indeed, many thousands of MOFs are referenced in various structural databases. Within this wide family of materials, many experience certain challenges, which often limit their use for practical applications, including their relatively poor thermal and chemical stability, cyclability, and sensitivity to trace contaminants. One promising approach to address these drawbacks lies with the hybridization of MOFs with other material counterparts to design combinatorial hybrid adsorbents exhibiting superior performance and enhanced properties, benefiting from synergetic effects from each component and interfacial properties engineering. The purpose of this work is to critically review hybridized MOF adsorbents for CO2 capture, with a prime focus on the different opportunities offered by hybridizing materials and additives to MOFs. The engineering, properties, and performance of hybridized MOFs are systematically reviewed, and opportunities and challenges are discussed. This work provides key parameters of the application of hybridized MOF adsorbents and presents recommendations for further research, thereby providing a roadmap for the synthesis and usage of these types of adsorbents for practical CO2 capture applications.