Defect and Linker Effects on the Binding of Organophosphorous Compounds in UiO-66 and Rare-Earth MOFs

Abstract

The adsorption of chemical warfare agents and their simulants by Zr (UiO-66) and rare-earth (Y, UiO-66-DOBDC analog)-based metal−organic frameworks (MOFs) is explored here using density functional theory. In particular, we investigate the role of linker functional group (OH, H) and metal atom identity on the binding energies of organophosphorous compounds. Commonly used cluster approximations for MOF secondary building units and various optimization constraints are compared with three-dimensional periodic results. An in-depth scan of potential binding sites and orientations reveals little effect due to metal identity, whereas the effect of linker functionalization depends on the substrate. This finding strongly suggests that full linkers and functional groups should be included in cluster models. Importantly, defect sites show considerably improved binding of organophosphorous compounds as compared to ideal clusters. Favorable binding is also demonstrated at two additional adsorption sites, ZrOH and μ 3 -OH, that likely play a role in the initial adsorption process. The results presented here portray the importance of including full threedimensional pore structures in the adsorption process of organophosphorous compounds in MOFs; a critical first step in the degradation of these harmful chemicals.

Impact of defects on the decomposition of chemical warfare agent simulants in Zr‐based metal organic frameworks

“…This is a highly abstracted model of the periodic MOFs, which may not give accurate energies. 39,40 We therefore computed DMMP reaction pathways for 2-defect μ 3 -OH elimination and 1-defect adjacent OH elimination using full periodic models with the CI-NEB method within CP2K. The periodic pathways and energies (shown in Figures S3 and S4) are consistent with those of the cluster system.…”

Computational Screening of Roles of Defects and Metal Substitution on Reactivity of Different Single- vs Double-Node Metal–Organic Frameworks for Sarin Decomposition

“…For example, Harvey et al computed binding energies of different CWAs, including sarin, to Zr6-UiO-66 and Y6-UiO-66 MOFs focusing on the impact of different missing linker defect sites on computed energetics. 63 While adsorption of CWA is known to not to be the RDS for the hydrolysis reaction, 38,39 this contribution is the first study of its kind to shed light on the systematic nature and chemical properties of defect sites in robust MOFs as they interact with CWAs. Focusing on the complete hydrolysis reaction coordinate, in addition to identifying the correct proton topology of a newly synthesized Zr12 double-node MOF, 64 we recently predicted higher reactivities for hydrolysis of sarin by its bi-defective framework than for any of its single-node analogs ( Figure 2).…”

Metal–Organic Frameworks Based on Group 3 and 4 Metals

“…Taking advantage of unique fluorescence properties of rare earth (RE) elements including yttrium and lanthanides, RE-MOFs have been applied in broad applications, such as light emitting, [72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88] sensing, [89][90][91][92][93][94] catalysis, [95][96][97] and imaging [98][99][100][101][102] (Figure 3).…”