(626c) Water in Zr-Based Metal-Organic Framework: Topology and Its Effect | AIChE

(626c) Water in Zr-Based Metal-Organic Framework: Topology and Its Effect

Authors 

Huang, L. - Presenter, University of Oklahoma
Topology screening and defect engineering lead to an effective manipulation of physical and chemical properties of metal-organic frameworks (MOFs). Taking the common missing linker defect as an example, the defective MOF generally possesses larger pores and a greater surface area/volume ratio, both of which favor an increased amount of adsorption. When it comes to the self-diffusion of adsorbates in MOFs, however, the missing linker is a double-edged sword: the unsaturated metal sites, due to missing linkers, could interact more strongly with adsorbates and result in a slower self-diffusion. Therefore, it is of fundamental importance to evaluate the two competing factors and reveal which one is dominating, a faster self-diffusion due to larger volume or a slower self-diffusion owing to strong interactions at unsaturated sites. In this presentation, we discuss the topology differences of three Zr-based MOFs, namely, UiO-66, NU-1000, and MOF-808. By molecular dynamics simulations, we discuss the behavior of water and dimethyl phosphate in those Zr-MOFs. The results reveal that unsaturated Zr sites bind strongly with IPA molecules, which in return would significantly reduce the self-diffusion coefficient of IPA. Besides this, for the same level of missing linkers, the location of defective sites also makes a difference. We expect such a theoretical study will provide an in-depth understanding of self-diffusion under confinement, inspire better defect engineering strategies, and promote MOF based materials for challenging real-life applications.