Hydrocarbon chemistry in irradiated CO2/CO/CH4/H2O/H2 mixtures—I

Norfolk, David J.; Skinner, Ronald F.; Williams, William J.

doi:10.1016/0146-5724(83)90159-0

Cited by 12 publications

(4 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the gas phase, the reaction of CO 2 + with H 2 has been well studied. CO 2 + reacts at close to collision-limited rates as 9,49,50 For (CO 2 ) 2 + , we can expect a similar hydrogen-atom abstraction reaction. 9,51 We can hope that the reaction between H 2 and the anion will be much slower.…”

Section: Resultsmentioning

confidence: 74%

“…In the gas phase, the reaction of CO 2 + with H 2 has been well studied. CO 2 + reacts at close to collision-limited rates as ,, For (CO 2 ) 2 + , we can expect a similar hydrogen-atom abstraction reaction. , We can hope that the reaction between H 2 and the anion will be much slower. It is known that the reaction of CO 3 - with H 2 is quite slow in the gas phase ( k < 5 × 10 6 M -1 s -1 52 ); however, there is no report for the reaction of H 2 with CO 2 anion cluster.…”

Section: Resultsmentioning

confidence: 86%

“…There have been extensive studies of ion−molecule reactions in gas-phase CO 2 . It is well-established that the primary positive ion in the radiolysis of CO 2 gas is CO 2 + and that CO 2 + forms clusters rapidly with CO 2 . − The atomic oxygen radical anion, O - , which is produced by dissociative electron attachment to CO 2 , is known to be the primary negative ion in the high-energy radiolysis. − To dissociate CO 2 to CO + O - , about 4.0 eV of energy is required (calculated from the bonding energy(O−CO) = 5.453 eV, and the electron affinity(O) = 1.461 eV) …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Transient Negative Species in Supercritical Carbon Dioxide: Electronic Spectra and Reactions of CO₂ Anion Clusters

et al. 2001

View full text Add to dashboard Cite

Transient absorption spectra following ionization of supercritical CO2 have been investigated using the pulse radiolysis technique. Absorption spectra measured from 400 to 800 nm suggest that at least two transient species absorb. We have previously reported that one species is (CO2)2 +. In the near UV region, we observed a transient species of which the lifetime and reactivity are different from the dimer cation. We assign this species to a dimer anion, (CO2)2 -, or an anion−molecule complex, (CO2 -)(CO2) x . Comparison with the photobleaching of CO2 anion clusters in solid rare gas matrixes and their reactivity with H2 and O2 confirm the assignment. Theoretical calculations, in which solvation is taken into account, are consistent with these assignments. It is well-established that the adiabatic electron affinity of CO2 is negative, but the adiabatic electron affinity of CO2 dimer has been calculated to be 0.89 eV for D 2 d symmetry (CO2)2 - in the gas phase. The calculations predict that CO2 - in a model continuum solvent is stable to autodetachment.

show abstract

Section: Resultsmentioning

confidence: 74%

Section: Resultsmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Transient Negative Species in Supercritical Carbon Dioxide: Electronic Spectra and Reactions of CO₂ Anion Clusters

et al. 2001

View full text Add to dashboard Cite

show abstract

“…Up to now, a number of theoretical and experimental investigations have been performed on the C 2 H 3 reactions with atoms, radicals and molecules, including those with H 2 , C 2 H 2 , CH 3 , CO, O 2 , NO, O, F, Cl, etc. [1][2][3][4][5][6][7][8][9][10][11] It is known that water molecules in the gas phase are widespread in atmospheric and combustion processes. Thus, the reaction of C 2 H 3 with H 2 O might influence the decay rate of the C 2 H 3 radical and might have further effect on the other chain reactions considered in combustion processes.…”

Section: Introductionmentioning

confidence: 99%

Theoretical study on mechanisms of the high-temperature reactions C2H3 + H2O and C2H4 + OHElectronic supplementary information (ESI) available: Figures of optimized geometries of the fragments of C2H5O radicals, C2H5O isomers and C2H5O transition states and table of harmonic vibration frequencies of C2H3, H2O, TSR/P1, C2H4 and OH. See http://www.rsc.org/suppdata/cp/b1/b109758j/

Liu

et al. 2002

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

The potential energy surface of the radical-molecule reaction C 2 H 3 + H 2 O in the gas phase is explored at the 6-31G(d,p) and 6-311G(d,p) B3LYP and single-point QCISD(T)/6-311G(2df,p) levels. The most favorable channel is the direct H-abstraction from H 2 O to C 2 H 3 leading to product P 1 C 2 H 4 + OH, whereas the other channels leading to the products P 2 CH 3 + CH 2 O, P 3 CH 3 CHO + H, P 4 cis-CH 2 CHOH + H and P 4 0 trans-CH 2 CHOH + H are kinetically much less competitive. For the direct H-abstraction channel, high-level energetic calculations at the QCISD(T)/6-311G(2df,p), QCISD(T)/6-311+G(2df,2p) and G2 levels using the B3LYP/6-31G(d,p) and QCISD/6-31G(d,p) optimized geometries are further performed to estimate the thermal rate constants over a wide temperature range 200-5000 K for comparison with future laboratory measurements. The calculated barrier heights at the QCISD(T)/6-311+G(2df,2p) and G2 levels based on the QCISD/6-31G(d,p) geometries with zero-point vibrational energy (ZPVE) correction are 12.6 and 13.0 kcal mol À1 , respectively. The results indicate that the C 2 H 3 + H 2 O reaction might play an important role at high temperatures (T > 1800 K) in the presence of gaseous water and should be incorporated in the C 2 H 3 -modeling of hydrocarbon-fuel combustion processes. Discussions are also made in comparison with the analogous reactions C 2 H 3 + H 2 and C 2 H + H 2 O. While the addition-elimination mechanism of another important radicalmolecule reaction C 2 H 4 + OH has been the subject of extensive theoretical and experimental studies, its Habstraction process leading to C 2 H 3 + H 2 O has received little attention. For the C 2 H 4 + OH ! C 2 H 3 + H 2 O channel, our calculations predict ZPVE-corrected barriers, 5.6 and 5.4 kcal mol À1 , respectively, at the QCISD(T)/6-311+G(2df,2p)//QCISD/6-31G(d,p) and G2//QCISD/6-31G(d,p) levels, and reveal its importance at high temperatures (T > 560 K). In the range 720-1173 K, the calculated high-level rate constants are quantitatively in good agreement with the measured values. However, our calculated activation energy, 9.5 and 9.3 kcal mol À1 at the QCISD(T)/6-311+G(2df,2p)//QCISD/6-31G(d,p) and G2//QCISD/6-31G(d,p) levels with ZPVE correction, respectively, suggests that the experimentally determined value 4-5 kcal mol À1 may be underestimated and future rate constant measurements over a wide temperature range including T > 1200 K may be desirable.

show abstract

Calculations of the Rate Constants for the Hydrogen Abstraction Reactions C2H3+CH4→C2H4+CH3 and C2H3+C2H6→C2H4+C2H5

Liu

Xiao

et al. 2002

ChemPhysChem

View full text Add to dashboard Cite

Hydrocarbon chemistry in irradiated CO2/CO/CH4/H2O/H2 mixtures—I

Cited by 12 publications

References 48 publications

Transient Negative Species in Supercritical Carbon Dioxide: Electronic Spectra and Reactions of CO₂ Anion Clusters

Transient Negative Species in Supercritical Carbon Dioxide: Electronic Spectra and Reactions of CO₂ Anion Clusters

Calculations of the Rate Constants for the Hydrogen Abstraction Reactions C2H3+CH4→C2H4+CH3 and C2H3+C2H6→C2H4+C2H5

Contact Info

Product

Resources

About

Hydrocarbon chemistry in irradiated CO2/CO/CH4/H2O/H2 mixtures—I

Cited by 12 publications

References 48 publications

Transient Negative Species in Supercritical Carbon Dioxide: Electronic Spectra and Reactions of CO2 Anion Clusters

Transient Negative Species in Supercritical Carbon Dioxide: Electronic Spectra and Reactions of CO2 Anion Clusters

Calculations of the Rate Constants for the Hydrogen Abstraction Reactions C2H3+CH4→C2H4+CH3 and C2H3+C2H6→C2H4+C2H5

Contact Info

Product

Resources

About

Transient Negative Species in Supercritical Carbon Dioxide: Electronic Spectra and Reactions of CO₂ Anion Clusters

Transient Negative Species in Supercritical Carbon Dioxide: Electronic Spectra and Reactions of CO₂ Anion Clusters