期刊
ACS APPLIED MATERIALS & INTERFACES
卷 13, 期 26, 页码 30565-30575出版社
AMER CHEMICAL SOC
DOI: 10.1021/acsami.1c05062
关键词
metal-organic frameworks; nerve agent simulant; hydrolysis; catalytic destruction; product inhibition; Langmuir-Freundlich model; binding constant; aqua-ligand
资金
- Defense Threat Reduction Agency [HDTRA1-18-1-0003]
- National Defense Science and Engineering Graduate Fellowship (NDSEG) program
- Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource [NSF ECCS-1542205]
- State of Illinois
- International Institute for Nanotechnology (IIN)
- MRSEC program at the Materials Research Center [NSF DMR1720139]
- Keck Foundation
- State of Illinois through IIN
This study investigates the effects of product inhibition on catalytic activity in the degradation of chemical warfare agents, particularly those containing a phosphorous-fluorine bond. Results indicate substantial product inhibition on catalyst activity after several turnovers, with apparent product binding constants obtained to quantitatively describe the inhibition effects over time. The study highlights the importance of understanding product inhibition in the catalytic hydrolysis of chemical warfare agents.
Rapid degradation/destruction of chemical warfare agents, especially ones containing a phosphorous-fluorine bond, is of notable interest due to their extreme toxicity and typically rapid rate of human incapacitation. Recent studies of the hydrolytic destruction of a key nerve agent simulant, dimethyl 4-nitro-phenylphosphate (DMNP), catalyzed by Zr-6-based metal-organic frameworks (MOFs), have suggested deactivation of the active sites due to inhibition by the products as the reaction progresses. In this study, the interactions of two MOFs, NU-1000 and MOF-808, and two hydrolysis products, dimethyl phosphate (DMP) and ethyl methyl phosphonate (EMP), from the hydrolysis of the simulant (DMNP) and nerve agent ethyl methylphosphonofluoridate (EMPF), resembling the hydrolysis degradation product of the G-series nerve agent, Sarin (GB), have been investigated to deconvolute the effect of product inhibition from other effects on catalytic activity. Kinetic studies via in situ nuclear magnetic resonance spectroscopy indicated substantial product inhibition upon catalyst activity after several tens to several thousand turnovers, depending on specific conditions. Apparent product binding constants were obtained by fitting initial reaction rates at pH 7.0 and pH 10.5 to a Langmuir-Freundlich binding/adsorption model. For the fits, varying amounts/concentrations of candidate inhibitors were introduced before the start of catalytic hydrolysis. The derived binding constants proved suitable for quantitatively describing product inhibition effects upon reaction rates over the extended time course of simulant hydrolysis by aqua-ligand-bearing hexa-zirconium(IV) nodes.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据