Shaping and silane coating of a diamine-grafted metal-organic framework for improved CO2 capture
Jong Hyeak Choe, Jeoung Ryul Park, Yun Seok Chae, Dae Won Kim, Doo San Choi, Hyojin Kim, Min‐Jung Kang, Hwimin Seo, Yong‐Ki Park, Chang Seop Hong
Abstract
Abstract Although metal-organic framework (MOF) powders can be successfully shaped by conventional methods, postsynthetic functionalization of the shaped MOFs remains almost unexplored, yet is required to overcome intrinsic limitations, such as CO 2 adsorption capacity and stability. Here, we present a scalable synthesis method for Mg 2 (dobpdc) MOF and its shaped beads, which are obtained by using a spray dry method after mixing Mg 2 (dobpdc) powders with alumina sol. The synthesized MOF/Al beads have micron-sized diameters with a moderate particle size distribution of 30–70 μm. They also maintain a high mechanical strength. N-ethylethylenediamine (een) functionalization and coating with long alkyl chain silanes results in een-MOF/Al-Si, which exhibits a significant working capacity of >11 wt% CO 2 capture and high hydrophobicity. The een-MOF/Al-Si microbeads retain their crystallinity and improved CO 2 uptake upon exposure to humid conditions for three days at a desorption temperature of 140 °C.