Decomposition of dimethyl methylphosphonate on TiO2(110): principal component analysis applied to X-ray photoelectron spectroscopy

Zhou, Jing; Varazo, Kris; Reddic, J. E.; Myrick, Michael L.; Chen, Donna

doi:10.1016/s0003-2670(03)01008-0

Cited by 42 publications

(85 citation statements)

References 20 publications

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“…The O 1s binding energy of the methoxy group is about 532.8 eV. The appearance of the phosphoryl group overlaps with other DMMP decomposition studies, such as methanol (32 amu) [20], dimethyl ether (46 amu) [21,22], methane (16 amu) [20,21] or H 2 [20,21], strongly implying intact desorption under these conditions.…”

Section: Low Dmmp Coverage -Heating In Vacuumsupporting

confidence: 75%

Thermal desorption of dimethyl methylphosphonate from MoO₃

Head

Tang

Hicks

et al. 2017

Catalysis, Structure & Reactivity

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Organophosphonates are used as chemical warfare agents, pesticides, and corrosion inhibitors. New materials for the sorption, detection, and decomposition of these compounds are urgently needed. To facilitate materials and application innovation, a better understanding of the interactions between organophosphonates and surfaces is required. To this end, we have used diffuse reflectance infrared Fourier transform spectroscopy to investigate the adsorption geometry of dimethyl methylphosphonate (DMMP) on MoO 3 , a material used in chemical warfare agent filtration devices. We further applied ambient pressure X-ray photoelectron spectroscopy and temperature programmed desorption to study the adsorption and desorption of DMMP. While DMMP adsorbs intact on MoO 3 , desorption depends on coverage and partial pressure. At low coverages under UHV conditions, the intact adsorption is reversible. Decomposition occurs with higher coverages, as evidenced by PCH x and PO x decomposition products on the MoO 3 surface. Heating under mTorr partial pressures of DMMP results in product accumulation.

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Section: Low Dmmp Coverage -Heating In Vacuumsupporting

confidence: 75%

Thermal desorption of dimethyl methylphosphonate from MoO₃

Head

Tang

Hicks

et al. 2017

Catalysis, Structure & Reactivity

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“…In the search for new materials for applications and a better understanding of DMMP surface chemistry, especially on metal oxides, adsorption studies with a focus on analyzing surface species have been conducted on TiO2, [2][3][4][5][6][7][8] ZnO, 2 Al2O3, 2,9-11 MgO 2,9 WO3, 2,5 La2O3, 9 Fe2O3, 9,12,13 CeO2, 14 SiO2, 12,15 Y2O3, 16 and combinations of these as supported metal oxides. 17,18 Several techniques have been used to investigate the surface species, including infrared (IR) spectroscopy, 2,[4][5][6][7][8][9][10][12][13][14][15][16][17][18] Raman spectroscopy, 18 X-ray photoelectron spectroscopy (XPS), 3,6,14,16,17 inelastic tunneling spectroscopy, ,11 temperature programmed desorption (TPD), 3,12,14 Auger electron spectroscopy, 12 X-ray diffraction, 17 and ion chromatography. 17 The results...…”

Section: Introductionmentioning

confidence: 99%

Adsorption of Dimethyl Methylphosphonate on MoO₃: The Role of Oxygen Vacancies

Head

Tsyshevsky²,

Trotochaud

et al. 2016

J. Phys. Chem. C

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Dimethyl methylphosphonate (DMMP) is a common chemical warfare agent simulant and is widely used in adsorption studies. To further increase the understanding of DMMP interactions with metal oxides, ambient pressure X-ray photoelectron spectroscopy was used to study the adsorption of DMMP on MoO3, including the effects of oxygen vacancies, surface hydroxyl groups, and adsorbed molecular water. Density functional theory calculations were used to aid in the interpretation of the APXPS results. An inherent lack of Lewis acid metal sites results in weak interactions of DMMP with MoO3. Adsorption is enhanced by the presence of oxygen vacancies, hydroxyl groups, and molecular water on the MoO3 surface, as measured by photoelectron spectroscopy. Computational results agree with these findings and suggest the

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“…Several studies were carried out to understand the mechanism of the adsorption and decomposition processes on such oxides as alumina-supported cerium oxide and iron co-impregnated oxide [31], manganese oxide [32], monoclinic tungsten oxide (m-WO 3 ) [33], cerium oxide, Fe 2 O 3 , silica [34][35][36][37][38], and TiO 2 [39][40][41][42]. The thermal oxidative decomposition study of DMMP on amorphous manganese oxide and Al 2 O 3 -supported manganese oxide catalyst has shown the DMMP oxidation to CO 2 [32].…”

Section: Introductionmentioning

confidence: 99%

“…On hydrated SiO 2 about 10% of DMMP was decomposed and the only detectable decomposition products were methylphosphonate (MP) and methanol. The decomposition of DMMP on TiO 2 surfaces is carried out either as photodegradation of DMMP in a stepwise fashion to give methylphosphonic acid, PO 4 3-, H 2 O, and CO 2 as products [39,40]; or cleavage of P-OCH 3 groups [41,42], with the production of Ti-OCH 3 surface species, and this is accompanied with the consumption of the surface hydroxyl groups. Reduction of a P-O bond order then occurs as adsorbed phosphonate species are formed.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of dimethyl methylphosphonate and trimethyl phosphate on calcium oxide: an ab initio study

2008

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Ab initio study of the adsorption of dimethyl methylphosphonate (DMMP) and trimethyl phosphate (TMP) on three types of models simulating the calcium oxide surface (non-hydroxylated Ca 4 O 4 , completely hydroxylated Ca 4 O 4 (OH) 2 H 2 , and partially hydroxylated Ca 4 O 4 (OH)H) was performed. The target molecule and the surface hydroxyl groups were optimized while the CaO fragment was kept frozen. The intermolecular interactions were investigated applying Bader's Atoms in Molecules theory. The maps of electrostatic potential of the studied adsorption systems were also produced. The interaction energies of studied adsorption systems corrected by the basis set superposition error were obtained. The most energetically favorable adsorption of DMMP and TMP was found at the configuration where the oxygen atoms of the P=O and methoxy groups point toward the Ca cation of the surface. The P atom points toward the O atom of the surface and forms a P-O chemical bond. This configuration was revealed for the non-hydroxylated and partially hydroxylated CaO-DMMP and CaO-TMP systems. The presence and number of surface hydroxyl groups on the CaO models play a key role in the adsorption of the studied compounds. DMMP and TMP were found to be much less stable on the completely hydroxylated CaO surface where they are adsorbed only via weak electrostatic interactions and H-bonding to the surface oxygen atoms and hydroxyl groups. TMP was found to be slightly more stable on this type of surface than DMMP. The difference in stability is even larger if one compares this TMP system with the complex of tabun adsorbed on completely hydroxylated CaO surface model (Michalkova et al. Chem Phys Lett 438:72, 2007).

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Decomposition of dimethyl methylphosphonate on TiO2(110): principal component analysis applied to X-ray photoelectron spectroscopy

Cited by 42 publications

References 20 publications

Thermal desorption of dimethyl methylphosphonate from MoO₃

Thermal desorption of dimethyl methylphosphonate from MoO₃

Adsorption of Dimethyl Methylphosphonate on MoO₃: The Role of Oxygen Vacancies

Adsorption of dimethyl methylphosphonate and trimethyl phosphate on calcium oxide: an ab initio study

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Decomposition of dimethyl methylphosphonate on TiO2(110): principal component analysis applied to X-ray photoelectron spectroscopy

Cited by 42 publications

References 20 publications

Thermal desorption of dimethyl methylphosphonate from MoO3

Thermal desorption of dimethyl methylphosphonate from MoO3

Adsorption of Dimethyl Methylphosphonate on MoO3: The Role of Oxygen Vacancies

Adsorption of dimethyl methylphosphonate and trimethyl phosphate on calcium oxide: an ab initio study

Contact Info

Product

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Thermal desorption of dimethyl methylphosphonate from MoO₃

Thermal desorption of dimethyl methylphosphonate from MoO₃

Adsorption of Dimethyl Methylphosphonate on MoO₃: The Role of Oxygen Vacancies