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Volumn 130, Issue 47, 2008, Pages 15879-15888

Experimental and theoretical study of the reactions between small neutral iron oxide clusters and carbon monoxide

Author keywords

[No Author keywords available]

Indexed keywords

ABLATION; CARBON; CARBON CLUSTERS; CARBON MONOXIDE; CHEMICAL OXYGEN DEMAND; DENSITY FUNCTIONAL THEORY; EXCITONS; EXPERIMENTS; HIGH PERFORMANCE LIQUID CHROMATOGRAPHY; IRON COMPOUNDS; LASER ABLATION; MASS SPECTROMETERS; MASS SPECTROMETRY; OXIDATION; PROBABILITY DENSITY FUNCTION;

EID: 56749163569     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja8023093     Document Type: Article
Times cited : (159)

References (123)
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  • 66
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    • Notes: The experimental bond strength (D0) for FeO+ is D0(Fe+-O, 3.52 ± 0.02 eV (ref 22a, The experimental D0 values for FeO- are D0(Fe--O, D0(Fe-O, EA(FeO)-EA(Fe, 5.52 ± 0.01 eV and D0(Fe-O , D0(Fe-O, EA(FeO)-EA(O, 4.21 ± 0.01 eV, in which D0(Fe-O, 4.18 ± 0.01 eV (ref 22b) and EA denotes electron affinity: EA(O, 1.46111 ± 0.00004 eV (ref 22c, EA(Fe, 0.151 ± 0.003, ref 22d, and EA(FeO, 1.4945 ± 0.0002 eV (ref 22e, The calculated D0 values for FeO n, n, 1-3) are all less than 4.75 eV, whereas those for FeOn, n, 1-3) are all greater than 5.75 eV in ref 21a
    • - (n = 1-3) are all greater than 5.75 eV in ref 21a.
  • 88
    • 56749171598 scopus 로고    scopus 로고
    • Notes: The pressure (P) is calculated with the ideal gas law P, nkT in which k and T are the Boltzmann constant and the gas temperature, respectively. The molecular density (n) is determined by n, F/A/C (refs 30a and b) in which F is the gas flow rate (in molecule/s, A is the cross-sectional area defined by the inner diameter of the fast flow reactor, and C, γkT/m) 1/2; parameters of helium are used: γ, 5/3 and m, mass of He atom] is the speed of sound. The gas flow rate F is determined as F, N/Δ where N is number of gas molecules per pulse injected from the second nozzle and Γ is the duration of gas pulse (2.0 ms in our experiment, The (average) N value is quite accurately determined by monitoring the amount of gas (∼5% uncertainty) injected into the vacuum after running the pulsed valve (at 10 Hz) for a fixed period of time. The unc
    • -3 are determined for 1% and 5% CO conditions, respectively.
  • 89
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    • Gaussian, Inc, Wallingford, CT
    • Frisch, M. J.; et al. Gaussian 03 , revision C.02; Gaussian, Inc.: Wallingford, CT, 2004.
    • (2004) Gaussian 03 , revision , Issue.C.02
    • Frisch, M.J.1
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    • Steinfeld, J. I.; Francisco, J. S.; Hase, W. L. Chemical Kinetics and Dynamics; Prentice-Hall: Upper Saddle River, NJ, (a) p 26 and (b) pp 313-314.
    • Steinfeld, J. I.; Francisco, J. S.; Hase, W. L. Chemical Kinetics and Dynamics; Prentice-Hall: Upper Saddle River, NJ, (a) p 26 and (b) pp 313-314.
  • 103
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    • Determination of σcorr(FeO2, CO) involves finding solution for x in a nonlinear equation: Ae -x, B(1-e-x)/x-C, 0, in which A, IHe(FeO2)/I He(FeO3, B, ln[Igas(FeO 3)/IHe(FeO3, C, I gas(FeO2)/Igas(FeO3, and σcorr(FeO2, CO, x, B)/n/l. The uncertainty of x, B is determined by calculations of the numerical derivatives of x, B with respect to the independent mass signal magnitudes Igas and IHe with 10% uncertainty
    • He with 10% uncertainty).
  • 105
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    • Themochemical Tables
    • 4th ed. J. Phys. Chem. Ref. Data
    • Chase, M. W. NIST-JANAF Themochemical Tables, 4th ed. J. Phys. Chem. Ref. Data Monograph 9, 1998.
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    • Chase, M.1    NIST-JANAF, W.2
  • 108
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    • The adopted B3LYP/6-311+G* method predicts that the quintet FeOO2 (FeO3 molecule containing-O-O-moiety, 5B2, C2ν symmetry, see 5I2 in Supporting Information Figure S7) is only above the groundstate FeO 3 (1A1′, D3h) by 0.032 eV (zero-point-vibration corrected, see Tables S4 and S11 in the Supporting Information, Considering that the B3LYP functional favors higher spin states and another functional such as BPW91 with 6-311+G* basis set predicts that the singlet FeO3 (1A1′) is below the quintet FeOO2 (5B2) by 1.38 eV, FeOO2 is not considered to be significantly populated in the experiments
    • 2 is not considered to be significantly populated in the experiments.
  • 123
    • 56749119066 scopus 로고    scopus 로고
    • The experimental work (Figure 1) suggests that single-iron sites (FeO2,3 as models) are active, whereas two-iron assemblies (Fe 2O4,5 as models) are not, for the oxidation of CO; however, in the model catalytic cycles (FeO1-3 and Fe 2O3-5 as model catalysts, see cycles I and II in Figure 8, the most difficult (rate-limiting) step is O-O bond breaking. We thus give up choosing single irons as the best catalytic sites when plotting Figure 9. Although Fe2O4,5 clusters do not oxidize CO under the employed gas-phase conditions (limited CO pressure, bath gas cooling rate, and reaction time, two-iron assemblies on the surface of catalysts can coordinate a CO molecule as long as the rate constant for energy dissipation through surface phonons and bath gases is fast enough ≥ 1011 s-1, see the rate of direct dissociation of Fe2O4/7I1 → Fe2
    • 2 may be efficiently catalyzed by the iron oxides.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.