A density function theory study on the properties and decomposition of CF3OF

The density function theory was used to calculate the potential energy surface for the decomposition of CF3OF. The geometries, vibrational frequencies and energies of all stationary points were obtained. The calculated harmonic frequencies agreed well with the experimental ones. Three decomposition channels of CF3OF were studied. The calculated reaction enthalpy (29.85 kcal/mol) of the elimination reaction CF3OF --> CF2O + F-2 was in good agreement with the experimental value (27.7 kcal/mol). The O-F bond of CF3OF is broken easily by comparing the energies, while the decomposition channel to yield the CF30 and F radicals is the main reaction path. (C) 2002 Published by Elsevier Science B.V.

Catalytic decomposition of hydrazine over supported molybdenum nitride catalysts in a monopropellant thruster

The catalytic decomposition of hydrazine over a series of MoNx/gamma-Al2O3 catalysts with different Mo loadings was investigated in a monopropellant thruster (10 N). When the Mo loading is equal to or higher than the monolayer coverage of MoO3 on gamma-Al2O3, the catalytic performance of the supported molybdenum nitride catalyst is close to that of the conventionally used Ir/gamma-Al2O3 catalyst. The MoNx/gamma-Al2O3 catalyst with a loading of about 23wt% Mo (1.5 monolayers) shows the highest activity for hydrazine decomposition. There is an activation process for the MoNx/gamma-Al2O3 catalysts at the early stage of hydrazine decomposition, which is probably due to the reduction of the oxide layer formed in the passivation procedure.

Direct decomposition of NO by microwave heating over Fe/NaZSM-5

Catalytic decomposition of NO was studied over Fe/NaZSM-5 catalyst. Novel results were observed with the microwave heating mode. The conversion of NO to N-2 increased remarkably with the increasing of Fe loading. The effects of a series of reaction parameters, including reaction temperature, O-2 concentration, NO concentration, gas flow rate and H2O addition, on the productivity of N-2 have been investigated. It is shown that the catalyst exhibited good endurance to excess O-2 in the microwave heating mode. Under all reaction conditions, NO converted predominantly to N-2. The highest conversion of NO to N-2 was up to 70%. (C) 2002 Elsevier Science B.V. All rights reserved.

Decomposition of transformer oil under ultrasonic irradiation during degassing process

In the degassing process of transformer oil with ultrasonic waves, decomposition of the oil was observed. Light hydrocarbons, including methane, ethane, ethylene, acetylene, propane etc, were found to be released continuously from the oil into headspace within a closed vial placed in an ultrasonic field. The gases came from decomposition of hydrocarbon Molecules under cavitation effect.

Nitrogen-15 signals of leaf-litter-soil continuum as a possible indicator of ecosystem nitrogen saturation by forest succession and N loads

National Key Research and Development Program [2010CB833502]; National Natural Science Foundation of China [30600071, 40601097, 30590381]; Chinese Academy of Sciences [KZCX2-YW-432, O7V70080SZ, LENOM07LS-01]; GUCAS [O85101PM03]

High-quality hydrogen from the catalyzed decomposition of formic acid by Pd-Au/C and Pd-Ag/C

Pd-Au/C and Pd-Ag/C were found to have a unique characteristic of evolving high-quality hydrogen dramatically and steadily from the catalyzed decomposition of liquid formic acid at convenient temperature, and further this was improved by the addition of CeO2(H2O)(x).

Facile Synthesis and Optical Property of Porous Tin Oxide and Europium-Doped Tin Oxide Nanorods through Thermal Decomposition of the Organotin

Porous SnO2 and SnO2-Eu3+ nanorods have been facilely prepared using triphenyltin hydroxide microrods as precursors. The porous structure of SnO2 nanorods, which was aggregated by small SnO2 nanocrystallites, has been confirmed by TEM images and nitrogen adsorption-desorption isotherms. The optical property of the porous SnO2-Eu3+ nanorods was investigated by UV-vis absorption and photoluminescence spectra.

Perovskite-Like Mixed Oxides (LaSrMn1-x Ni (x) O4+delta, 0 a parts per thousand currency sign x a parts per thousand currency sign 1) as Catalyst for Catalytic NO Decomposition: TPD and TPR Studies

Catalytic NO decomposition on LaSrMn1-x Ni (x) O4+delta (0 a parts per thousand currency sign x a parts per thousand currency sign 1) is investigated. The activity of NO decomposition increases dramatically after the substitution of Ni for Mn, but decreases when Mn is completely replaced by Ni (x = 1.0). The optimum value is at x = 0.8. These indicate that the catalytic performance of the samples is contributed by the synergistic effect of Mn and Ni. O-2-TPD and H-2-TPR experiments are carried out to explain the change of activity. The former indicates that only when oxygen vacancy is created, could the catalyst show enhanced activity for NO decomposition; the latter suggests that the best activity is obtained from catalyst with the most matched redox potentials (in this work, the biggest Delta T and Delta E values).

Effect of strontium substitution on the activity of La2-xSrxNiO4 (x=0.0-1.2) in NO decomposition

The aim of this work is to study the effect of Sr substitution on the redox properties and catalytic activity of La2-xSrxNiO4 (x = 0.0-1.2) for NO decomposition. Results suggest that the x = 0.6 sample shows the highest activity. The characterization (TPD, TPR, etc.) of samples indicates that the x = 0.6 sample possesses suitable abilities in both oxidation and reduction, which facilitates the proceeding of oxygen desorption and NO adsorption. At temperature below 700 degrees C, the oxygen desorption is difficult, and is the rate-determining step of NO decomposition. With the increase of reaction temperature (T > 700 degrees C), the oxygen desorption is favorable and, the active adsorption of NO on the active site (NO + V-o + Ni2+ -> NO--Ni3+) turns out to be the rate-determining step. The existence of oxygen vacancy is the prerequisite condition for NO decomposition, but its quantity does not relate much to the activity.