Effect of Carbon Dioxide on the Degradation of Chemical Warfare Agent Simulant in the Presence of Zr Metal Organic Framework MOF-808
- Stony Brook Univ., NY (United States). Dept. of Materials Science and Chemical Engineering
- Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
- Emory Univ., Atlanta, GA (United States). Cherry L. Emerson Center for Scientific, and Dept. of Chemistry
- U.S. Army CCDC Chemical Biological Center, Aberdeen Proving Ground, MD (United States)
- Emory Univ., Atlanta, GA (United States). Dept. of Chemistry
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)
- Kennesaw State Univ., Kennesaw, GA (United States). Dept. of Chemistry
- Stony Brook Univ., NY (United States). Dept. of Materials Science and Chemical Engineering; Brookhaven National Lab. (BNL), Upton, NY (United States). Division of Chemistry
Developing novel and more efficient filters for chemical warfare agent (CWA) decomposition remains an important challenge for modern technology due to the continuous threat those weapons present in the event of use. Recently, metal–organic frameworks (MOFs) have attracted attention as potential catalysts for nerve agent decomposition. However, in order to improve their performance under battlefield conditions, it is crucial to understand the influence of ambient contaminants such as carbon dioxide on CWA adsorption and decomposition. In this paper, we present a comprehensive experimental and computational study on the influence of CO2 on the adsorption and decomposition of the CWA simulant dimethyl methyl phosphonate (DMMP) by the Zr-based MOF-808. The study combined in situ synchrotron powder X-ray diffraction (PXRD) with variable-temperature infrared spectroscopy (VTIR) and computations. PXRD and experiments with pure CO2 revealed that the MOF framework contracts by 0.2% after CO2 saturation and CO2 adsorbs within the MOF-808 framework via dispersion forces with an enthalpy of adsorption of -32.2 ± 1.8 kJ/mol. From five DRIFTS experiments conducted in various gas flow regimes we established that CO2 interferes with the decomposition of DMMP due to the formation of carbonate species, while if it is used as a regeneration agent, it accelerates the desorption of DMMP and DMMP decomposition products. In situ PXRD experiments showed that CO2 also limited expansion of the framework due to the formation of carbonate species by 40% in comparison to values in a control experiment with N2. The main conclusions of the computational study are (a) CO2 reversibly adsorbs onto MOF-808 via both μ3-OH groups located within the tetrahedral pores of the MOF and/or to the MOF surface with stabilizing dispersion interactions, (b) the presence of DMMP provides stability to the CO2–(μ3-OH) moiety, which hinders the μ3-OH transfer to the DMMP molecule required for the nerve-agent decomposition until the carbonyl to carbonate transformation is completed, and (c) CO2 molecules are not sufficient for the regeneration of the MOF when DMMP decomposition products are present but rather there is desorption of bound DMMP.
- Research Organization:
- Brookhaven National Laboratory (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Grant/Contract Number:
- SC0012704; AC02-06CH11357
- OSTI ID:
- 1577425
- Alternate ID(s):
- OSTI ID: 1600824
- Report Number(s):
- BNL--212375-2019-JAAM
- Journal Information:
- Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 23 Vol. 31; ISSN 0897-4756
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
In Situ Probes of Capture and Decomposition of Chemical Warfare Agent Simulants by Zr-Based Metal Organic Frameworks
Metal–Organic Framework- and Polyoxometalate-Based Sorbents for the Uptake and Destruction of Chemical Warfare Agents