Hybrid Porous Framework Contactors for Efficient CO2 Capture

Abstract

Metal-Organic Frameworks (MOFs), a class of crystalline microporous materials, have attracted great interest in separation applications due to their extensive surface area and modifiable pore size variations. These applications of MOFs, which are gas separation, storage and capture, heterogeneous catalysis, and sensing, among others, have spurred extensive research into their potential applications in other fields continuously growing. However, the susceptibility of MOFs to degradation when exposed to water is a significant limitation for some of them. As a result, numerous strategies have been devised to reduce water absorption and improve the stability of MOFs for practical applications. Hydrophobic surface modifications are an effective technique for combating the water sensitivity of MOFs. By involving MOFs with hydrophobic properties, it is possible to avoid their breakdown and suppress competing adsorption in water, thus ensuring their sustained performance in aqueous environments.

Covalent Organic Frameworks (COFs), microporous organic materials assembled from organic building blocks via strong covalent bonds, have demonstrated promising efficacy in various applications. Nonetheless, synthesizing highly ordered and stable COF structures remains challenging. Several investigated the synthesis of unique building elements with tailored chemical functions, allowing for the assembly of stable and well-defined COF structures. High-ordered COFs, including those formed with triazine-based building blocks, have been synthesized successfully, but their stability is often compromised at elevated temperatures and in the presence of water. Utilizing the superior quality and stability of the bonds between COF building blocks as compared to MOFs, researchers have used coatings and chemical modifications to improve the resilience of COFs.

Excitingly, the hybridization of MOFs and COFs offers a promising strategy for developing water-stable microporous adsorbents with enhanced properties for aqueous applications. Combining the large surface area of MOFs and the tunable chemistry of COFs can improve adsorption in aquatic environments. The inherent water stabilization properties of COFs combine with the ability of MOFs to control pore size to produce water-stable microporous adsorbents with superior performance and application.

In conclusion, the hybridization of MOF-MOF, and MOF-COF offers a compelling strategy for developing water-stable microporous adsorbents with improved stability and adsorption capacities. Incorporating both materials into such hybrid materials holds tremendous potential for furthering their applicability in diverse aqueous environments. In this thesis report the objective was to integrate pure MOFs as a hybrid which are Mg-MOF-74 and UiO-66(Zr) to Mg-MOF-74@UiO-66(Zr) using solvothermal method.

Date of Award	18 Dec 2023
Original language	American English
Supervisor	Ludo Dumee (Supervisor)