Abstract
Recent studies have suggested that the gas-phase hydrolysis of nerve agents by Zr-based metal-organic frameworks (MOFs) may be limited by product inhibition resulting from strong bidentate binding of the hydrolysis products to the Zr6-nodes. A potential method to avoid this problem is to deposit single-atom catalysts on the nodes so that the products bind in a more favorable monodentate mode. Such catalytic active sites can be characterized with atomic precision, enabling detailed computational mechanistic studies. Thus, we used density functional theory to perform a comprehensive screening of single-atom transition-metal catalysts, in varying oxidation states, deposited on NU-1000 nodes for the gas-phase hydrolysis of the nerve agent sarin. By calculating the complete reaction pathways for M-NU-1000 systems, we discovered that the highest reaction barrier varies between catalysts, highlighting the need to consider more than a single reaction step when screening a large number of diverse materials. The single-metal catalysts are predicted to exhibit lower product desorption energies than unfunctionalized NU-1000. By comparing their relative turnover frequencies using the energetic span model, we identified several catalysts that are predicted to be more active than the parent MOF for this reaction. Finally, we explored periodic trends and molecular descriptors for their effect on catalytic activity.
Original language | English (US) |
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Pages (from-to) | 1310-1323 |
Number of pages | 14 |
Journal | ACS Catalysis |
Volume | 10 |
Issue number | 2 |
DOIs | |
State | Published - Jan 17 2020 |
Funding
We gratefully acknowledge DTRA for the financial support (grant HDTRA1-18-1-0003). This research used the resources of the Quest high performance computing facility at Northwestern University. This research was conducted with Government support under and awarded by DoD, Air Force Office of Scientific Research, National Defense Science and Engineering Graduate (NDSEG) Fellowship, 32 CFR 168a to M.L.M.
Keywords
- chemical warfare agents
- density functional theory
- metal-organic frameworks
- nerve agent hydrolysis
- single-atom catalysts
ASJC Scopus subject areas
- Catalysis
- General Chemistry