Utilization of Metal-Organic Frameworks in the Degradation of Chemical Warfare Agents

Metal-organic frameworks (MOFs) have been an area of interest for filter applications because of their high surface area, porosity, and catalytic capabilities. MOFs are comprised of metal nodes connected via organic linkers to form complex geometries which can be finely tuned during synthesis. A zirconium-based MOF called UiO-66 has demonstrated particular promise in promoting the hydrolysis of nerve agents. Various modulators were added during synthesis to control particle size (100-1900 nm) and defect level (0-24%). Hydrolysis of a chemical warfare agent simulant, dimethyl 4-nitrophenyl phosphate (DMNP), was used to determine differences in reactivity between samples. The rate of hydrolysis was improved with decreased particle size, suggesting the reaction is limited to the external surface. Heightened defect levels allowed for some diffusion into the MOF resulting in quicker hydrolysis rates; however, the increase in rate was not substantial compared to the effect of particle size on rate.