Studies of the sorption of triethyl phosphate by ion-exchanged smectite clays

Williamson, Colin J.; O’Brien, Paul

doi:10.1039/jm9940400565

Cited by 7 publications

(6 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here, the adsorption and degradation were monitored by IR and magic angle spinning (MAS) NMR spectroscopy. Smectites (generally species of the formula (Ca,Na,H)(Al,Mg,Fe,Zn) 2 (Si,Al) 4 O 10 (OH) 2 · x H 2 O) were also treated with DMMP . As with other studies, the M n + complex (e.g., Mg 2+ ) of phosphonate was formed for use as a model complex.…”

Section: Decomposition Reactionsmentioning

confidence: 99%

Destruction and Detection of Chemical Warfare Agents

et al. 2011

View full text Add to dashboard Cite

Section: Decomposition Reactionsmentioning

confidence: 99%

Destruction and Detection of Chemical Warfare Agents

et al. 2011

View full text Add to dashboard Cite

“…Organophosphonate surface chemistry is an important but not a very well-characterized area of chemistry . Within the last several years important studies of the fundamentals of the interactions between organophosphonate compounds and metal oxide surfaces have been carried out. − Dimethyl methylphosphonate (DMMP), I , is a widely used model compound for the simulation of the interactions of phosphonate esters with surfaces. Phosphonate esters occur widely in the spectrum of toxic man-made chemicals, being used as pesticides and chemical warfare agents.…”

Section: Introductionmentioning

confidence: 99%

Adsorption and Decomposition of Dimethyl Methylphosphonate on Metal Oxides

1997

View full text Add to dashboard Cite

The adsorption and decomposition of dimethyl methylphosphonate (DMMP) have been examined on four different metal oxide surfaces: aluminum oxide, magnesium oxide, lanthanum oxide, and iron oxide. Aluminum, magnesium, and lanthanum oxides are observed to behave in much the same way, with initial binding of the PO species to the surface at an acid site, followed by stepwise elimination of the methoxy groups, beginning at temperatures as low as 50 °C, which combine with surface hydrogens to yield methanol that evolves from the surface. The final product observed for these oxides is a surface-bound methylphosphonate, with the P−CH3 bond intact, which is resistant to further oxidation even in the presence of 70 Torr of oxygen at 300−400 °C. Adsorption on iron oxide yields a different sequence of events, with the initial adsorption occurring again with the PO moiety binding to an acid site, although there is some indication of the formation of a second type of surface complex. The primary interaction on iron oxide appears to be much stronger than with the other oxides, and probably involves the unidentate coordination of the DMMP to a Lewis acid site on the surface. Nonselective elimination of both the methoxy and the phosphorus-bound methyl groups begins only after heating above 200 °C, but occurs with total elimination of the methyl and methoxy groups observed after heating above 300 °C in vacuum. The ease with which iron oxide cleaves the P−CH3 bond is attributed to the availability of multiple oxidation states to the iron atom. Participation of the Fe(III)/Fe(II) redox couple in the reaction provides a low-energy path for oxidative cleavage of the P−CH3 bond. The other oxide surfaces cannot provide a similar path, and on these surfaces the P−CH3 bond is resistant to cleavage. The use of infrared diffuse reflectance techniques, observing, in particular, the methyl stretch region of the infrared spectrum, has allowed the almost complete characterization of the decomposition processes which occur after DMMP adsorbs on aluminum oxide, magnesium oxide, lanthanum oxide, and iron oxide.

show abstract

“…1246.5 and 1145.2 cm −1 , respectively, a considerable shift of 10−20 cm −1 . 39 This, apart from the appearance of characteristic peaks at 1088.4 and 631.5 cm −1 , signifies the presence of free perchlorate anions (ClO 4 − ) that are unlikely to participate in the coordination sphere of the system. 39 The ionic conductivity of the synthesized quasi-solid electrolyte was assessed by employing temperature-step electrochemical impedance spectroscopy.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…As highlighted in Figure b, the ν s (P = O) and ν as (PO3) bands are observed at ca . 1246.5 and 1145.2 cm –1 , respectively, a considerable shift of 10–20 cm –1 . This, apart from the appearance of characteristic peaks at 1088.4 and 631.5 cm –1 , signifies the presence of free perchlorate anions (ClO 4 – ) that are unlikely to participate in the coordination sphere of the system …”

Section: Resultsmentioning

confidence: 99%

Nonflammable and Stable Quasi-Solid Electrolytes: Demonstrating the Feasibility of Application in Rechargeable Solid-State Magnesium Batteries

Seggem

Rani

Basak

2022

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

Quasi-solid electrolytes (QSEs) are an interesting research area for rechargeable magnesium batteries (RMBs). A solid-state electrolyte is favored in battery research as it can offer several processing advantages apart from addressing the safety issues pertaining to highenergy-density batteries. Herein, we showcase a unique QSE that can be easily synthesized from triethyl-phosphate (TEP) as the host medium and 1.5 M magnesium perchlorate (Mg(ClO 4 ) 2 ) as the electrolyte. The gelation and physico-chemical interactions between Mg 2+ and TEP solvent molecules leading to the formation are comprehensively analyzed by 1 H-, 13 C-, 31 P-NMR, and FTIR. The QSE is not only thermally stable, but also the electrochemical properties assessed by impedance spectroscopy in combination with d.c. polarization studies, linear sweep, and cyclic voltammetry techniques reveal that it does satisfy all of the pre-requisites to support excellent ionic conduction. The ionic conductivity of ∼4.0 × 10 −3 S cm −1 at 25 °C and an estimated cationic transport number of ca. 0.37 for Mg 2+ ions along with electrochemical stability >2.7 V and nonflammability underscore its suitability to be explored for RMB applications. In our attempts to justify, a prospective cathode material, δ-MnO 2 , was concurrently synthesized, characterized, and paired with the QSE and evaluated for its test-cell performance. The assembled δ-MnO 2 |QSE|Mg cells were appraised by employing conventional cyclic voltammetry, impedance spectroscopy, and galvanostatic charge−discharge studies, wherein an apparently impressive initial capacity of 65 mAh•g −1 at a current density 10 mA•g −1 displays a steady performance decline over multiple cycles. Our extensive follow-up investigations employing XRD, FESEM, EDS, and XPS to analyze the observed performance inadequacy reveal that this unexpected deviation is potentially related to a transformation of the active-material morphology and was not a case of electrolyte instability or unwarranted side reactions at the electrode−electrolyte interface. The QSE remains a feasible option for use in rechargeable Mg 2+ion batteries possibly paired with alternate electrodes.

show abstract

Studies of the sorption of triethyl phosphate by ion-exchanged smectite clays

Cited by 7 publications

References 12 publications

Destruction and Detection of Chemical Warfare Agents

Destruction and Detection of Chemical Warfare Agents

Adsorption and Decomposition of Dimethyl Methylphosphonate on Metal Oxides

Nonflammable and Stable Quasi-Solid Electrolytes: Demonstrating the Feasibility of Application in Rechargeable Solid-State Magnesium Batteries

Contact Info

Product

Resources

About