MOF-74 and UTSA-16 film growth on monolithic structures and their CO2 adsorption performance

Monolithic structures offer a cost-effective and practical platform for scaling up gas separation processes in comparison to traditional packing systems. In this study, the immobilization of several metal-organic frameworks (MOFs) namely, MOF-74(Ni) and UTSA-16(Co) on commercial cordierite monolith (600 cpsi) was investigated and their corresponding adsorptive performance in CO2 capture was assessed systematically. To gain control over crystal nucleation and growth, various bottom-up growth techniques were employed and optimized with respect to loading, thickness, and adsorption characteristics of the MOFs films. Our results indicated that the choice of suitable coating procedure depends primarily on the type of the MOF material used. It was shown that layer-by-layer technique followed by a secondary growth is a suitable method for MOF-74(Ni) film growth on the monolith walls which gives rise to ∼52 wt% MOF loading, whereas for UTSA-16(Co), in-situ dip coating was found to be a promising coating method which results in ∼55 wt% MOF weight gain. Moreover, the MOF-coated monoliths displayed relatively moderate CO2 adsorption capacity with fast kinetics.