A simulation study of linker vacancy distribution and its effect on UiO-66 stability

Abstract

In this work, we computationally investigate the impact of the distribution of linker vacancies on the relative stability of defected UiO-66 structures. Analysis of a significant number of defected structures reveals that higher defect numbers correlate with lower stability, but variations in missing linker distribution and orientation contribute to widely differing amorphization pressures. Our results suggest that structures with more evenly distributed vacancies exhibit a positive linear relationship between amorphization pressure and bulk modulus. Furthermore, we found structures with a disproportionate number of missing linkers with the same orientation and structures where a large volume of the framework remains pristine, display outlier behavior in this respect. Evaluation of anisotropic elastic moduli uncovers directional instability in structures with a high number of vacancies with the same orientation. These findings have important implications for designing and optimizing UiO-66-based materials, aiding in defect configuration selection for specific applications.