Rate constant measurements for the overall reaction of OH + 1-butanol → products from 900 to 1200 K

Article abstract of DOI:10.1021/jp211885p

The rate constant for the overall reaction OH + 1-butanol → products was determined in the temperature range 900 to 1200 K from measurements of OH concentration time histories in reflected shock wave experiments of tert-butyl hydroperoxide (TBHP) as a fast source of OH radicals with 1-butanol in excess. Narrow-linewidth laser absorption was employed for the quantitative OH concentration measurement. A detailed kinetic mechanism was constructed that includes updated rate constants for 1-butanol and TBHP kinetics that influence the near-first-order OH concentration decay under the present experimental conditions, and this mechanism was used to facilitate the rate constant determination. The current work improves upon previous experimental studies of the title rate constant by utilizing a rigorously generated kinetic model to describe secondary reactions. Additionally, the current work extends the temperature range of experimental data in the literature for the title reaction under combustion-relevant conditions, presenting the first measurements from 900 to 1000 K. Over the entire temperature range studied, the overall rate constant can be expressed in Arrhenius form as 3.24 × 10^-10 exp(-2505/T [K]) cm³ molecule^-1 s^-1. The influence of secondary reactions on the overall OH decay rate is discussed, and a detailed uncertainty analysis is performed yielding an overall uncertainty in the measured rate constant of ±20% at 1197 K and ±23% at 925 K. The results are compared with previous experimental and theoretical studies on the rate constant for the title reaction and reasonable agreement is found when the earlier experimental data were reinterpreted.

Full text of DOI:10.1021/jp211885p

Article
pubs.acs.org/JPCA
Rate Constant Measurements for the Overall Reaction
of OH + 1-Butanol → Products from 900 to 1200 K
Genny A. Pang,* Ronald K. Hanson, David M. Golden, and Craig T. Bowman
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
S
* Supporting Information
ABSTRACT: The rate constant for the overall reaction OH + 1-butanol → products was
determined in the temperature range 900 to 1200 K from measurements of OH
concentration time histories in reflected shock wave experiments of tert-butyl hydroperoxide
(TBHP) as a fast source of OH radicals with 1-butanol in excess. Narrow-linewidth laser
absorption was employed for the quantitative OH concentration measurement.
A detailed kinetic mechanism was constructed that includes updated rate constants for
1-butanol and TBHP kinetics that influence the near-first-order OH concentration decay
under the present experimental conditions, and this mechanism was used to facilitate the rate
constant determination. The current work improves upon previous experimental studies of
the title rate constant by utilizing a rigorously generated kinetic model to describe secondary
reactions. Additionally, the current work extends the temperature range of experimental data in the literature for the title reaction
under combustion-relevant conditions, presenting the first measurements from 900 to 1000 K. Over the entire temperature range
studied, the overall rate constant can be expressed in Arrhenius form as 3.24 × 10−10 exp(−2505/T [K]) cm3 molecule−1 s−1. The
influence of secondary reactions on the overall OH decay rate is discussed, and a detailed uncertainty analysis is performed
yielding an overall uncertainty in the measured rate constant of 20% at 1197 K and 23% at 925 K. The results are compared
with previous experimental and theoretical studies on the rate constant for the title reaction and reasonable agreement is found
when the earlier experimental data were reinterpreted.
OH + CH CH CH CH OH
INTRODUCTION
3
2
2
2
■
In 2006, DuPont and BP announced a partnership to begin
production of 1-butanol from biomass, also referred to as
biobutanol, because of the advantages of biobutanol over
ethanol for use as a fuel additive or alternative fuel.1 In the years
following, efforts toward developing detailed chemical kinetic
models for high-temperature combustion of 1-butanol have
expanded rapidly to support the introduction of biobutanol into
the transportation sector. Dagaut and co-workers2,3 and Moss
et al.4 each published separate detailed kinetic models of high-
temperature 1-butanol oxidation in 2008, using data from a jet-
stirred reactor and shock tube ignition delay times, respectively,
as validation targets. Researchers from around the world have
quickly followed suit, adding to the literature additional 1-butanol
mechanisms and experimental validation targets5−12 to increase
understanding of 1-butanol combustion kinetics.
The reaction of OH with 1-butanol is a major fuel consump-
tion pathway during combustion, and therefore, the rate con-
stant for this reaction must be known well to develop an
accurate detailed kinetic mechanism for 1-butanol combustion.
The abstraction of a hydrogen atom from 1-butanol by OH can
proceed through five different reaction channels which result in
different product species.
→ H O + CH CH CHCH OH
(1b)
(1c)
(1d)
(1e)
2
3
2
2
OH + CH CH CH CH OH
3
2
2
2
→ H O + CH CHCH CH OH
2
3
2
2
OH + CH CH CH CH OH
3
2
2
2
→ H O + CH CH CH CH OH
2
2
2
2
2
OH + CH CH CH CH OH
3
2
2
2
→ H O + CH CH CH CH O
2
3
2
2
2
The overall rate constant for reaction 1 is defined as the sum of
the site-specific rate constants for reactions 1a−1e. Reactions
1a−1d result in a water molecule and a hydroxybutyl radical,
and we will use a naming convention which denotes different
hydroxybutyl radicals by their radical position relative to the
OH group (i.e., the α-hydroxybutyl radical from reaction 1a is
missing a hydrogen atom from the first carbon adjacent to the
OH group, the β-hydroxybutyl radical from reaction 1b the
second carbon from the OH group, and so on). Reaction 1e
results in a water molecule and a 1-butoxy radical. Early detailed
Received: December 9, 2011
Revised: February 20, 2012
Published: February 21, 2012
OH + CH CH CH CH OH
3
2
2
2
→ H O + CH CH CH CHOH
(1a)
2
3
2
2
© 2012 American Chemical Society
2475
dx.doi.org/10.1021/jp211885p | J. Phys. Chem. A 2012, 116, 2475−2483

The Journal of Physical Chemistry A
Article
kinetic mechanisms of 1-butanol combustion included site-specific
rate constants for reactions 1a−1e estimated from analogous
reactions with alkanes or ethanol.2−5 The mechanism of Black
et al.7 used additional knowledge from theoretical calculation of
the individual bond energies in the 1-butanol molecule to
estimate the site-specific rate constants for reaction 1. The
mechanism of Grana et al.8 made site-specific rate constant
estimations for reaction 1 on the basis of a systematic approach
for similar reactions of hydrocarbon species,13 while also con-
sidering quantum calculations of Galano et al.14 for reactions of
OH with alcohols.
Recently, studies focusing directly on the high-temperature
rate constant for reaction 1 have been undertaken, including
high-temperature experimental measurements15 and ab initio
studies with high-level electronic structure calculations.16 Vasu
et al.15 conducted the first high-temperature rate constant mea-
surements for reaction 1 using tert-butyl hydroperoxide (TBHP)
as a fast OH precursor in shock tube experiments in the tem-
perature range 1017−1269 K. Their rate constant measure-
ments only determined the overall rate constant for reaction 1,
and not the rate constants for the site-specific reactions. Ab
initio calculations, such as those published by Zhou et al.,16 can
be carried out to yield site-specific rate constants, and con-
fidence in these calculations is typically vetted by comparison of
the sum with experimental data.
with added improvements in that the 1-butanol composition of
the test mixtures was verified to within 5% by laser absorption
at 3.39 μm in an external multipass absorption cell, and the
impurities in the shock tube were experimentally confirmed to
contribute less than 1 ppm OH using the laser absorption
method described below.
A detailed description of the laser absorption method used
for the current experiments can be found elsewhere,17 and
therefore, only a short description will be given. A narrow-
linewidth laser absorption diagnostic technique employing a
Spectra-Physics 380 ring-dye cavity with a temperature-tuned
intracavity AD*A frequency-doubling crystal was used to
quantitatively measure the time evolution of the OH
concentration using the absorption feature in the ultraviolet
(UV) spectrum, i.e., the R1(5) absorption line in the OH A−X
(0,0) band near 306.7 nm. The OH absorption coefficient for
the R1(5) transition was taken from the work of Herbon et al.19
The incident and transmitted laser intensities were sampled at
a frequency of 1 MHz. A minimum OH detection limit of
∼0.5 ppm at 1200 K and 1.0 atm is possible using this
diagnostic technique, with an estimated accuracy of 3%.
KINETIC MODELING
■
Several secondary reactions are expected to contribute to
consumption and production of OH, including reactions in the
TBHP decomposition mechanism and reactions in the 1-butanol
pyrolysis/oxidation mechanism, and therefore, the determi-
nation of the title rate constant requires kinetic modeling.
A detailed kinetic mechanism was constructed to include
secondary reactions of importance involving both TBHP and 1-
butanol kinetics. A base mechanism presented in a previous
work17 was used as the starting point; this base mechanism
includes alkane kinetics from the JetSurF 1.0 mechanism20 and
added reactions shown to accurately describe measured OH
concentration time histories during neat TBHP decomposi-
tion.17 This base mechanism is an improvement to that
used in the Vasu et al.15 analysis, as this mechanism correctly
describes the OH behavior in neat TBHP decomposition. The
following types of reactions to describe the 1-butanol kinetics
were added to the base mechanism of the current works.
The reported experimental rate constant of Vasu et al.15 are
sensitive to kinetic modeling, and recent improvements in
kinetic modeling of the OH precursor17 and 1-butanol6−9,18
draw attention to deficiencies in their analysis, causing concerns
about the accuracy of their reported rate constant. Furthermore,
the temperature range studied by Vasu et al. (1017−1269 K)
provides limited confidence in the temperature dependence of
the rate constants obtained by ab initio calculations for combustion-
relevant conditions. These two concerns motivate the current
study. We present the results of OH concentration time history
measurements in shock tube experiments with mixtures of tert-
butyl hydroperoxide (TBHP) and 1-butanol dilute in argon.
Narrow-linewidth laser absorption by OH was employed for
time-resolved measurements of the OH concentration decay
in temperatures from 900 to 1200 K. A detailed kinetic
mechanism was constructed that includes updated rate
constants for all reactions of TBHP and 1-butanol that
influence secondary OH consumption and production in the
near-first-order OH concentration decay under the present
experimental conditions, and this mechanism was used to
determine the overall rate constant for reaction 1. The
measured overall rate constant is compared to previously
published recommendations15 and ab initio calculations.16
1. Reactions of 1-butanol, including bimolecular reactions
with OH and H radicals.
2. Reactions of 1-butoxy and hydroxybutyl radicals,
including unimolecular isomerization reactions and
unimolecular β-scission decomposition reactions.
3. Reactions of smaller 1-butanol fragments, including
bimolecular reactions with OH radicals and unimolecular
β-scission decomposition reactions.
EXPERIMENTAL SECTION
Figure 1 presents a reaction path diagram for reaction of
1-butanol illustrating the reactions considered. Thermodynamic
data for all new chemical species added to the base mechanism
were taken from Sarathy et al.12 who used the THERM pro-
gram21 to calculate temperature-dependent enthalpy and entropy
values. Rate constants for the reactions added for 1-butanol
kinetics were taken from recent literature experiments and
calculations.12,22−29 A method based on work by Curran30 was
used to estimate rate constants for reactions where appropriate
published rate constants could not be found, and a description
of our procedure is provided in the Appendix. For unimolecular
reactions where only the high-pressure-limit rate constant could
be found, the variation of the rate constant with pressure was
estimated using the Kassel Integral method29 with S = Smax/2.
■
All experiments were performed behind reflected shock waves
in the Stanford Kinetics Shock Tube Facility, a high-purity
stainless steel shock tube with an inner diameter of 14.13 cm
and an adjacent heated mixing assembly composed of a
stainless steel manifold and a 12 L stainless-steel mixing tank.
Mixtures were prepared manometrically using a commercially
available solution of 70%, by weight, tert-butyl hydroperoxide
(TBHP) in water and anhydrous 1-butanol (99.8% purity),
both from Sigma Aldrich. Argon gas (99.998% purity), supplied
by Praxair, was used as the mixture diluent. The shock tube
facility and the mixture preparation process used are identical to
that described in detail elsewhere.17 The current experimental
procedure closely follows the procedure used by Vasu et al.,15
2476
dx.doi.org/10.1021/jp211885p | J. Phys. Chem. A 2012, 116, 2475−2483

The Journal of Physical Chemistry A
Article
Figure 1. Reaction pathways important in the calculation of OH concentration for the present experiments. Reactions involved in OH consumption
are solid red and reactions involved in OH production are open green. The relative magnitudes of the rate constants to different product channels of
reactions 1 at 1197 K are illustrated by the thickness of the reaction arrow. The branching ratios for reactions 1a−1e from Zhou et al.16 are listed next
to the arrows.
The reactions and corresponding rate constants that were
added to and/or modified in the base mechanism can be found
in Table 1, which also lists the reactions and rate constants in
the base mechanism suggested to be important in describing
the OH concentration time history during TBHP decom-
position.17 Table 1 also includes the reaction numbers that will
be used in this work. We will refer to this mechanism as the
1-butanol/TBHP mechanism from hereon. Though this is not a
comprehensive mechanism for describing pyrolysis or oxidation
of 1-butanol, it does contains all of the reactions which would
be expected to influence the OH concentration time history
under the current experimental conditions and the best-known
rate constants at present.
To determine the overall rate constant for reaction 1, the
value of k1 in the 1-butanol/TBHP mechanism was varied until
the simulated OH concentration time history best fit the
measured OH concentration decay rate. The site-specific rate
constants k1a through k1e used in the 1-butanol/TBHP mecha-
nism during the analysis were calculated with the temperature-
dependent branching ratios from the Zhou et al.16 calculations
using the G3 potential energy surface. Figure 1 illustrates these
branching ratios at 1197 K. In this study, the branching ratios
were assumed to be constant within the variations of k1. The
CHEMKIN-PROsuite of programs by Reaction Design was
used to perform all mechanism simulations in this study, and
constant internal energy and constant volume constraints were
assumed.
decomposition of 1-butanol and the lower temperature limit
was set by slow decomposition of the OH precursor. Pressures
of nominally 1 atm were used, with the exception of a single
measurement at 2 atm to compare to similar conditions of Vasu
et al.15 Sample measurement traces of the OH concentration
time history are shown in Figure 2 at 1197 and 925 K. These
data, along with data from additional measurements at different
temperatures, are provided in the Supporting Information. The
OH concentration time histories typically follow a near-exponential
decay after the peak OH concentration is reached. The OH
concentration time history simulation using the 1-butanol/
TBHP mechanism, which describes the OH consumption by
reaction 1 along with secondary OH consumption and
production, with the best-fit rate constant for reaction 1, is
shown in comparison with the measured traces in Figure 2. The
effect of perturbations of 30% to k1 are also shown, illustrating
the sensitivity of the OH decay rate to this rate constant. At
temperatures below 1000 K, the decomposition of TBHP
occurs over a finite time scale, as shown in the example
measurement trace at 925 K in Figure 2. At these temperatures,
the OH concentration time history is accurately modeled by the
1-butanol/TBHP mechanism at early times, and only the
postpeak OH behavior shows sensitivity to k1. In the modeling
calculations, the initial TBHP concentration used for the
calculation was inferred directly from the initial OH
concentration measured in experiments for temperatures
greater than 1000 K; further discussion of this procedure is
described in a previous work.17
RESULTS AND DISCUSSION
■
The overall rate constant for reaction 1 was determined with
the 1-butanol/TBHP mechanism for temperatures from 900 to
1200 K, and the individual data points are shown on an
Arrhenius plot in Figure 3. The measured rate constant was
found to be independent of both pressure and initial mixture
Rate Constant Determination. The experiments were
performed with a dilute mixture of TBHP and 1-butanol in
argon, with initial 1-butanol-to-TBHP concentration ratios of
12 and 20. Temperatures of 900−1200 K were studied; the
upper limit of the temperature range was constrained by
2477
dx.doi.org/10.1021/jp211885p | J. Phys. Chem. A 2012, 116, 2475−2483

The Journal of Physical Chemistry A
Article
a
Table 1. List of Reactions of the 1-Butanol/TBHP Mechanism of the Current Work
rate constant
no.
1a
reaction
A
b
E
ref
4.85 × 1013
1.41 × 1013
0.00
0.00
3.910 × 103
5.383 × 103
current work
current work
current work
current work
current work
ref 17
OH + CH CH CH CH OH → H O + CH CH CH CHOH
3
2
2
2
2
3
2
2
1b
OH + CH CH CH CH OH → H O + CH CH CHCH OH
3
2
2
2
2
3
2
2
1c
1d
1e
2
3.92 × 1013
1.67 × 1014
6.77 × 1012
3.57 × 1013
1.26 × 1014
2.30 × 1013
2.49 × 1013
0.00
0.00
0.00
0.00
0.00
0.00
0.00
4.319 × 103
7.700 × 103
7.030 × 103
3.575 × 104
1.529 × 104
5.223 × 103
2.655 × 103
OH + CH CH CH CH OH → H O + CH CHCH CH OH
3
2
2
2
2
3
2
2
OH + CH CH CH CH OH → H O + CH CH CH CH OH
3
2
2
2
2
2
2
2
2
OH + CH CH CH CH OH → H O + CH CH CH CH O
3
2
2
2
2
3
2
2
2
(CH ) COOH → OH + (CH ) CO
3 3 3 3
3
ref 17
(CH ) CO → CH + CH COCH
3 3 3
3
3
4a
4b
ref 17
OH + (CH ) COOH → H O + O + t − C H
3 3 4 9
2
2
ref 17
OH + (CH ) COOH → H O + HO + iso − C H
4 8
3 3
2
2
5
6
7
3.57 × 1014
2.95 × 1013
1.65 × 1013
2.40
0.00
0.00
−2.111 × 103
4.594 × 103
0.00
ref 17
ref 17
ref 17
OH + OH → O + H O
2
CH COCH + OH → H O + CH CO + CH
3
3
3
2
2
CH + OH → CH (s) + H O
3
2
2
8a
8.79 × 1014
1.08 × 105
1.30 × 106
6.66 × 105
9.45 × 102
7.44 × 1041
1.14 × 1014
6.95 × 1027
5.52 × 1034
1.37 × 1039
1.40 × 1023
3.82 × 1033
2.92 × 1019
2.63 × 1026
1.31 × 1021
4.91 × 1021
1.82 × 1057
1.20 × 1014
9.00 × 1013
8.22 × 1041
1.30 × 1039
2.98 × 1029
2.68
2.69
2.915 × 103
4.440 × 103
4.471 × 103
6.756 × 103
8.701 × 103
4.049 × 104
2.900 × 104
3.488 × 104
4.268 × 104
3.943 × 104
3.009 × 104
3.354 × 104
1.756 × 104
1.295 × 104
3.795 × 103
6.477 × 103
8.795 × 103
0.00
ref 12
H + CH CH CH CH OH → H + CH CH CH CHOH
3
2
2
2
2
3
2
2
8b
ref 12
H + CH CH CH CH OH → H + CH CH CHCH OH
3
2
2
2
2
3
2
2
8c
2.40
ref 12
H + CH CH CH CH OH → H + CH CHCH CH OH
3
2
2
2
2
3
2
2
8d
2.54
ref 12
H + CH CH CH CH OH → H + CH CH CH CH OH
3
2
2
2
2
2
2
2
2
8e
3.14
ref 12
H + CH CH CH CH OH → H + CH CH CH CH O
3
2
2
2
2
3
2
2
2
9a
−8.59
−1.08
−4.49
−6.33
−7.72
−4.56
−6.22
−2.92
−4.74
−2.44
−2.30
−13.4
0.00
Appendix (f)
ref 23 (f)
Appendix (f)
Appendix (f)
Appendix (f)
ref 23 (f)
Appendix (f)
ref 24 (f)
ref 12
CH CH CH CHOH → CH = CHOH + C H
2 5
3
2
2
2
9b
CH CH CH CHOH → CH CH CH CH OH
3
2
2
2
2
2
2
10a
10b
11a
11b
12a
12b
13
CH CH CHCH OH → 1 − C H + OH
3
2
2
4 8
CH CH CHCH OH → CH = CHCH OH + CH
3
3
2
2
2
2
CH CHCH CH OH → C H + CH OH
3
2
2
3
6
2
CH CHCH CH OH → CH CH CH CH O
3
2
2
3
2
2
2
CH CH CH CH OH → C H + CH CH OH
2
2
2
2
2
4
2
2
CH CH CH CH OH → CH CH CH CH O
2
2
2
2
3
2
2
2
CH CH CH CH O → 1 − C H + CH O
3
2
2
2
3
7
2
14a
14b
14c
15
ref 26
OH + C H → H O + C H
2 4
2
5
2
ref 26
OH + C H → H + CH + CH O
2
5
3
2
ref 25 (R)
ref 26
OH + C H → C H OH
2
5
2 5
OH + CH OH → H O + CH O
2
2
2
16
0.00
0.00
ref 26
OH + C H OH → H O + C H O
2
4
2
2 4
17
−9.22
−7.93
−5.57
1.862 × 104
2.482 × 104
2.080 × 104
ref 27 (R)
ref 28 (R)
ref 26
CH CH OH → C H + OH
2
2
2 4
18
C H → C H + H
2
5
2 4
19
CH OH → CH O + H
2
2
a
All reactions are reversible. Rate constants are listed and expressed as k = ATb exp(−E/RT); units for A are cm3 mol−1s−1 for bimolecular reactions
and s−1 for unimolecular reactions, units for E are cal mol−1 K−1. All unimolecular reaction rate constants calculated at 1 atm, and the three-
parameter fits are valid for 800−1300 K. “(f)” denotes the pressure dependence was estimated from the high-pressure rate constant using Benson.29
“(R)” denotes rate constant calculated from the reverse rate constant using the mechanism thermodynamic data.
composition, and the results can be summarized in Arrhenius
form by
Influence of Secondary Reactions. OH Sensitivity. Under
the experimental conditions studied, reaction 1 dominates the
OH sensitivity, which is defined as Si = (∂xOH/∂ki) × (ki/xOH),
where Si is the OH sensitivity to reaction i, xOH is the OH
concentration, and ki is the rate constant for reaction i. Figure 4
shows the top seven reactions appearing in the OH sensitivity
calculated using the 1-butanol/TBHP mechanism for repre-
sentative experimental conditions at 925 K. The overall OH
sensitivity to reaction 1 is computed as the sum of the
individual channels. The top four reactions contributing to
−10
k = 3.24 × 10
3
−1 −1
exp(−2505/T [K]) cm molecule
s
1
valid from temperatures 896−1197 K. Table 1 presents the site-
specific rate constants for reactions 1a−1e calculated using the
temperature-dependent branching ratios from the Zhou et al.16
calculations using the G3 potential energy surface. Table 2
provides a list of the experimental conditions and the rate
constants for each individual data point.
2478
dx.doi.org/10.1021/jp211885p | J. Phys. Chem. A 2012, 116, 2475−2483

The Journal of Physical Chemistry A
Article
Table 2. Determinations of the Overall Rate Constant k1
from the Experimental OH Concentration Time History
Data
P
k1
mixture
T [K] [atm] [cm3 molecule−1 s−1
]
150 ppm 1-butanol, ∼13 ppm
1197
0.963
3.99 × 10−11
TBHP
1182
1095
1028
1196
2.044
1.045
1.144
0.943
3.99 × 10−11
3.32 × 10−11
2.82 × 10−11
3.99 × 10−11
201 ppm 1-butanol, ∼10 ppm
TBHP
1137
993
963
925
896
1.002
1.161
1.174
1.224
1.238
3.49 × 10−11
2.57 × 10−11
2.41 × 10−11
2.16 × 10−11
1.99 × 10−11
Figure 2. Measured OH concentration time histories for 1197 K and
0.96 atm for a mixture of 150 ppm 1-butanol and 13.3 ppm TBHP,
and 925 K and 1.22 atm for a mixture of 201 ppm 1-butanol and 10.3
ppm TBHP, compared with mechanism calculations using best-fit rate
for k1 and perturbations of 30%.
Figure 4. OH sensitivity calculation with the current mechanism for a
mixture of 201 ppm 1-butanol, 10.8 ppm TBHP at 925 K at 1.22 atm.
The overall rate constant for reactions 1a−1e dominates the OH
sensitivity. The four secondary reactions with the highest OH
sensitivity are reactions 2, 7, 12a, and 12b.
Figure 3. Arrhenius plot of the overall rate constant k1 determined in
the current work (filled squares) compared with rate constant
determination as reported in Vasu et al.15 (stars) and their data
reinterpreted with the mechanism from the current work (open
squares). Also shown are rate constant calculations from Zhou et al.16
The solid line is an Arrhenius fit to the current experimental data, and
the dashed line is a fit to the reinterpreted data of Vasu et al. using the
current mechanism. The error bars on the current data represent the
results of a detailed uncertainty analysis, Table 3.
comparison with reactions 12a and 12b.) Minor secondary OH
sensitivity interference is also present from reactions 8b, 8d,
10a, and 10b, however at a lesser amount than the reactions
shown in Figure 4. The top reactions appearing in the OH
sensitivity are similar for all temperatures studied in the current
work, with an exception at temperatures greater than 1000 K
where the OH sensitivity to reaction 2 becomes negligible.
The magnitudes of the OH sensitivity to the site-specific
channels of reaction 1 follow the order |S1a| > |S1c| while |S1b| ≈
|S1d| ≈ |S1e| ≈ 0. The branching ratio k1a/k1 is greater than k1c/
k1, thus influencing the ordering of the two reactions most
significant in the OH sensitivity. The branching ratios k1b/k1
and k1e/k1 are assumed to be 6% and 1%, respectively, at 925 K,
and therefore, these reactions do not contribute significantly to
the overall rate constant k1. Furthermore, the net OH consump-
tion through reaction 1b is expected to be near zero because
the β-hydroxybutyl radical product is expected to undergo a
rapid β-scission decomposition to reproduce OH via reaction
10a, and this reaction pathway also contributes to the low OH
sensitivity to reaction 1b. The explanation for the near-zero OH
sensitivity to reaction 1d is more complicated, and can be
secondary OH sensitivity interference are reactions 2, 7, 12a,
and 12b. The OH sensitivity to reaction 2, the unimolecular
decomposition of TBHP, is high only at early times, and k2 has
been measured in our previous work17 resulting in accurate
simulation of the early time OH concentration time history as
seen in Figure 2. The value for k7 was also measured in our
previous work17 and is assumed to accurately describe the
secondary reaction of OH with the final decomposition
products of TBHP because the measured values of k1 are
independent of initial mixture composition. Reactions 12a and
12b are competing reactions pathways for consumption of the
δ-hydroxybutyl radical, and therefore, the OH concentration is
sensitive only to the branching ratio k12a/k12, where k12 = k12a
+
k12b. (Reaction 9b also contributes to consumption and
production of the δ-hydroxybutyl radical; however, its influence
on the δ-hydroxybutyl radical concentration is negligible in
2479
dx.doi.org/10.1021/jp211885p | J. Phys. Chem. A 2012, 116, 2475−2483

The Journal of Physical Chemistry A
Article
Figure 5. OH reaction path analysis at 1197 K and 0.96 atm for a mixture of 150 ppm 1-butanol and 13.3 ppm TBHP. The net rate of OH
consumption (i.e., the observed pseudo-first-order rate) is 20% slower than the rate of OH consumption by reactions 1a−1e at these conditions. All
values represent calculations at 10 μs.
elucidated with the rate of production analysis discussed in the
following paragraphs.
in our earlier work17 and accurate rate constants are used in our
1-butanol/TBHP mechanism. Therefore, we are confident that
our mechanism accurately describes the rate of secondary OH
consumption by reaction 7.
The rate of production analysis also illustrates that the net
OH rate of production does not quite equal the OH rate of
production through reaction 1. For example, the net OH
production at 1197 K is 20% slower than the OH rate of
production by reaction 1. Thus, directly inferring a rate
constant for the title reaction from the observed pseudo-first-
order decay rate can lead to significant errors.
Reaction Pathway Analysis. Figure 5 presents a detailed
reaction pathway analysis of OH at 1197 K, and illustrates how
secondary reactions can contribute to consumption and
production of OH radicals. The net OH rate of production,
defined as d[OH]/dt, is also shown compared with the OH
rate of production due to reaction 1 and secondary reactions.
The secondary reactions that produce OH radicals are reactions
10a and 17, which subsequently occur after formation of the
β-hydroxybutyl and δ-hydroxybutyl radicals, respectively. In
these reactions, cleavage of the C−OH bond in the radical
fragment of 1-butanol occurs to produce an OH radical
indistinguishable from the OH produced from TBHP, thus
retarding the net rate of OH decay. As mentioned in the
previous paragraph, the decomposition of the β-hydroxybutyl
via reaction 10a contributes to the near-zero OH sensitivity to
reaction 1b. Because reaction 10b is a non-OH-producing
competing pathway for consumption of the β-hydroxybutyl
radical, minor OH sensitivity is present from reactions 10a and
10b. The amount of OH produced via reaction 17 is controlled
by the branching ratio of k12a/k12, and therefore, only reactions
12a and 12b appear in the OH sensitivity whereas the OH
sensitivity to reaction 17 is near zero.
Using the best-known rate constants listed in Table 1 to
describe the important 1-butanol secondary reactions in our 1-
butanol/TBHP mechanism, the branching ratio of k12a/k12 is
predicted to be 92% at 1197 K; thus the subsequent reactions
to follow reaction 1d are predicted to mostly lead to OH radical
production, causing a near-zero net consumption of OH via
reaction 1d and a negligible OH sensitivity to reaction 1d.
β-Hydroxybutyl and δ-hydroxybutyl radicals are also formed
from reactions 8b and 8d, and therefore, these reactions have a
minor contribution to the OH sensitivity. Secondary
consumption of OH radicals can also occur, where the
dominant secondary reaction for OH consumption is reaction
7, the bimolecular reaction of an OH radical with a methyl
radical; this reaction contributes to consumption of OH in any
experiment using TBHP as the OH precursor because methyl
radicals will be produced at similar levels as OH during TBHP
decomposition. The TBHP kinetic submechanism was studied
Recent results of ab initio calculations presented by Zhang
et al.31 indicate rate constant pressure dependence for
decomposition reactions, such as reaction 9a, which is stronger
than predicted using the Kassel Integral method,29 as was done
in the current work. The falloff factor calculated by Zhang et al.
for reaction 9a for is approximately an order of magnitude
larger than used in the current work, and if similar levels of
falloff exist for similar decomposition processes, such as
reaction 12a, this discrepancy can lead to large uncertainties
in the predicted branching ratio of k12a/k12. For example, with
the current mechanism this branching ratio is predicted to be
92% at 1197 K; using a rate constant pressure dependence for
reaction 12a that results in a 1 atm rate constant an order of
magnitude slower would yield a branching ratio k12a/k12 that
predicts that the reaction 12a pathway is no longer favored in
the consumption of the δ-hydroxybutyl radical, if all other rate
constants remain unchanged. However, Zhang32 has found that
the pressure dependence for the unimolecular isomerization
reactions is also expected to be stronger than currently
predicted. Therefore, we expect minimal effect on the
branching ratio k12a/k12 from the difference in pressure
dependence estimation methods provided that the high-
pressure-limit rate constants are correct. As previously
mentioned, the branching ratio k12a/k12 controls the amount
of OH reproduction that occurs via reaction 17 and can affect
the OH sensitivity to reaction 1d. The detailed uncertainty
analysis carried out in the following section shows that the
effect of the uncertainty of the branching ratio of k12a/k12 on the
rate constant determination of reaction 1 is the largest
contribution to the overall uncertainty near 1200 K. An
2480
dx.doi.org/10.1021/jp211885p | J. Phys. Chem. A 2012, 116, 2475−2483

The Journal of Physical Chemistry A
Article
uncertainty factor of 2 has been assumed for the rate constants
for our unimolecular reactions in the falloff region. Because of
the possibility of significant uncertainty in the branching ratio
Table 3. Individual and Coupled Uncertainties and Influence
on Reaction Rate Constant Determination at 1197 and 925 K
uncertainty sources (uncertainty
ascribed to source)
uncertainty in k1 at uncertainty in k1
k12a/k12, further experimental investigations of the pressure-
1197 K
at 925 K
dependent rate constants for reactions 12a and 12b are
recommended for future work.
Experimental Uncertainties
concentration ( 5%)
fitting ( 10%)
5%
5%
Uncertainty Estimation. A detailed uncertainty analysis,
accounting for both experimental and rate constant uncertain-
ties was carried out. The major experimental uncertainties are
the 1-butanol concentration in the reactant mixture and the
fitting of the data trace, and the major kinetic rate constant
uncertainties include the rate constants for reactions 2, 7, 8b,
8d, 10a, 10b, 12a, and 12b. An uncertainty of 30% each is
assumed for k2 and k7,17 and a factor of 2 uncertainty is
10%
Modeling Uncertainties
3%
10%
k7 ( 30%)
2%
4%
k1b/k1 ( 30%) & k10a (factor 2) &
k10b (factor 2)
6%
k1d/k1 ( 30%) & k12a (factor 2) &
k12b (factor 2)
14%
12%
k8b (factor 2)
3%
2%
k8d (factor 2)
4%
2%
assumed for each of the rate constants k8b, k8d, k10a, k10b, k12a
,
k2 ( 30%)
0%
15%
23%
and k12b. The branching ratios k1b/k1 and k1d/k1 also contribute
to the uncertainty in our rate constant determination, and the
uncertainty limits for these branching ratios are estimated to be
30%.
overall RSS uncertainty
20%
Vasu et al. determined an overall rate constant for k1 using a
detailed mechanism they constructed using an early 1-butanol
mechanism of Sarathy et al.,5 modified with TBHP chemistry
from literature sources.33,34 Although Vasu et al. pioneered the
high-temperature experimental work on the reaction of OH
with 1-butanol, recent improved understanding of high-
temperature 1-butanol oxidation kinetics allows for more
accurate selection of rate constants for secondary reaction
pathways in the current work. Three major differences exist
between the mechanism used in the current analysis and the
mechanism constructed by Vasu et al. First, the mechanism of
Sarathy et al.5 uses a rate constant for reaction 7 that is an order
of magnitude slower than the rate constant measured in our
recent work17 for the same reaction. The mechanism
constructed by Vasu et al. therefore does not correctly predict
secondary OH consumption and underpredicts the rate of OH
decay due to TBHP kinetics, and this introduces a 7% error in
their determination of k1. The uncertainty of k7 was not
included in the analysis of Vasu et al. Second, the analysis of
Vasu et al. assumes the rate constant for reaction 1b is equal to
that in the Sarathy et al. mechanism. This estimation of k1b is
approximately 3 times faster than the rate constant inferred in
the current analysis. The uncertainty of k1b was accounted for in
the uncertainty analysis of Vasu et al. Third, in the analysis by
Vasu et al., nearly all (>98% at 1017 K) of the δ-hydroxybutyl
radicals formed were predicted to be consumed through
isomerization reactions, instead of unimolecular decomposition
which leads to OH production via reaction 17. The rate
constants used for reactions k12a and k12b in the current work
suggest that the unimolecular decomposition pathway is
favored. Uncertainties for the rate constants k12a and k12b
were not included in the uncertainty analysis of Vasu et al.
The major differences between the current mechanism and the
mechanism used in the Vasu et al. analysis are presented in
Table 4, along with the influence of each of the mechanism
differences on k1. The overall influence of all of the mechanism
differences is also presented in Table 4.
To assess individual uncertainties, each independent source
of uncertainty was perturbed to its uncertainty limit, and the
experimental data trace was refit with a rate constant for k1.
Because not all of the uncertainty factors are independent, the
individual uncertainties cannot simply be combined using a
root-sum-squares method to obtain an overall uncertainty. For
example, the uncertainty in the rate constants k12a and k12b are
coupled together, as well as with the uncertainty of the
branching ratio k1d/k1. To determine the uncertainty influence
of a group of coupled uncertainty factors, each uncertainty
source in the group was perturbed to its uncertainty limit (with
the directions chosen such that the effects would not cancel
out), and the data trace was refit to obtain the uncertainty-
influenced k1 determination. A total uncertainty in k1 was
determined by combining the effects of the coupled
uncertainties with the independent individual uncertainties in
a root-sum-squares summation. The total estimated uncertainty
for k1 is 20% at 1197 K, where the majority of this uncertainty
is due to uncertainty in the branching ratio k1d/k1 and rate
constants k12a and k12b. At 925 K, this group of coupled
uncertainty factors contributes a smaller amount to the overall
uncertainty; however, the rate constant for reaction 2 has an
important role in the OH sensitivity calculations at these
temperatures. The total uncertainty in k1 at 925 K is estimated
to be 23%. At this temperature, the largest contribution to the
uncertainty becomes the rate constant for reaction 2. Table 3
provides details of the effect of the uncertainties on the final
rate constant determinations at 1197 and 925 K.
Comparison with Previous Experiments. Vasu et al.15
published the first high-temperature measurements of the rate
constant for reaction 1 from 1017 to 1269 K. Their experiments
employed techniques similar to those of the current work, using
narrow-linewidth laser absorption by OH in a shock tube and
TBHP as the OH precursor. The current set of experiments
includes one measurement at similar temperature, pressure, and
mixture composition (1182 K, 2.04 atm, 150 ppm 1-butanol,
13 ppm TBHP) as used in the Vasu et al.15 work (∼2.25 atm,
147 ppm 1-butanol, 11 ppm TBHP). The measured OH
concentration time history of the current work taken at 2 atm
displays a first-order decay rate that is closely equal to that
measured by Vasu et al., indicating that our measured OH
concentration decay rates are in excellent agreement with their
work.
Figure 3 compares the overall rate constant k1 determined in
the current work with the values determined by Vasu et al.
using their different mechanism. Also shown are the results of a
rate determination analysis for two raw data traces from the
work of Vasu et al. using the 1-butanol/TBHP mechanism
developed for the current work. The figure illustrates that the
rate constant as reported in the work of Vasu et al. is within
10% of the current work, with the discrepancy almost entirely
2481
dx.doi.org/10.1021/jp211885p | J. Phys. Chem. A 2012, 116, 2475−2483

The Journal of Physical Chemistry A
Article
overall rate constant is more representative of the measured
rate constant than the G3-calculated value.
Table 4. Differences in the Mechanisms Used for Analysis of
Measured OH Radical time Histories in the Current Work
and the Work of Vasu et al.,15 and the Influence on the Vasu
et al. Determination of k1 at 1165 K
CONCLUSIONS
■
rate constant(s) changed in
current mechanism
influence on
influence on
The rate constant for the overall reaction of OH with 1-
butanol was determined from OH concentration time
histories measured behind reflected shock waves, and the
results extend the range of experimentally determined high-
temperature rate constants to 900−1200 K; there were no
previous high-temperature measurements below 1017 K.
A detailed uncertainty analysis was conducted, yielding an
overall uncertainty of 20% at 1197 and 23% at 925 K. The
largest contribution to the overall uncertainty at 1197 K is the
branching ratio of the title reaction forming a δ-hydroxybutyl
radical and the rate constants for the reactions leading to
consumption of the δ-hydroxybutyl radical. For decreasing
temperatures, the influence of the uncertainty in the rate
constant for the OH precursor decomposition reaction also
becomes significant. Further experimental investigations on
the rate constants important in describing the reproduction
pathways of OH from 1-butanol are recommended.
justification
k1 at 1269 K k1 at 1017 K
k7 (×20)
ref 17
−7%
−7%
k1b (×0.33)
k12a & k12b (see text)
ref 16
−15%
+33%
+10%
−16%
+17%
−6%
refs 22, 23, 29
overall influence of current
mechanism changes
due to mechanistic differences in the analysis. This is expected
considering, as initially mentioned, our raw data of OH decay
were found to be in excellent agreement with their work. The
current experiments extend the temperature range of the Vasu
et al. work, providing the first rate constant measurements for
reaction of OH with 1-butanol from 900 to 1000 K. The
current determination of k1 shows a slightly stronger temper-
ature dependence than was found by Vasu et al., and this
temperature dependence is verified over a wider temperature
range.
Comparison with ab Initio Calculations. Zhou et al.16
performed detailed ab initio calculations for the site-specific
rate constants k1a, k1b, k1c, k1d, and k1e using a two-transition-
state model. They produced two different potential energy
surfaces, using CCSD(T) and G3 methods, yielding two sets of
rate constant calculations. Their site-specific rate constant
calculations can be summed to obtain the overall rate constant
k1, and these calculated values are compared to the current
experimental measurements in Figure 3. Their overall rate
constant k1 calculated with the two different methods differ by
up to 50% in the temperature range of interest, and the current
measurements of k1 fall between the two rate constant
calculations. Their calculation using the G3 potential energy
surface falls within the uncertainty estimate of the measured
value at 1197 K. At 925 K, however, both the G3- and
CCSD(T)-calculated value of k1 from Zhou et al. fall just
outside of the uncertainty limits of the measured rate constant.
The temperature dependence of the CCSD(T)-calculated
The measured OH concentration time histories of the
current work are in excellent agreement with the similar
experiments of Vasu et al.15 However, the current rate constant
determination of the title reaction disagrees with the Vasu
et al.15 determination for the same reaction by up to 10%,
where the discrepancy is almost entirely due to differences in
the kinetic mechanisms used for the analysis. Ab initio rate
constant calculations by Zhou et al. using a G3 potential energy
surface yield an overall rate constant that shows agreement with
the current experimental work at 1197 K, whereas their rate
constant obtained using a CCSD(T) potential energy surface
does not. At 925 K, however, both of their rate constant
calculations fall just outside of the uncertainty limits of the
measured rate constant. The CCSD(T)-computed overall rate
constant of Zhou et al. best matches the temperature
dependence of the current data.
a
Table 5. Families of Addition Reactions with Equivalent Rate Constants
rate constant
addition reaction
A
b
E
1.81 × 101
2.55
−3.533 × 103
C H + CH O → CH CH CH O
2
5
2
3
2
2
C H + CH O → CH CH CH CH O
3
7
2
3
2
2
2
3.04 × 106
1.68
6.619 × 103
CH + CH CHOH → CH CH CHOH
3
2
3
2
CH + CH CHCH OH → CH CH CHCH OH
3
2
2
3
2
2
C H + CH CHOH → CH CH CH CHOH
2
5
2
3
2
2
CH OH + C H → CH CHCH CH OH
2
3
6
3
2
2
7.54 × 107
1.28 × 106
1.20
1.60
−1.705 × 103
2.7767 × 103
OH + C H → CH CHCH OH
3
6
3
2
OH + 1‐C H → CH CH CHCH OH
4
8
3
2
2
CH OH + C H → CH CH CH OH
2
2
4
2
2
2
2‐C H OH + C H → CH CH CH CH OH
2
4
2
4
2
2
2
2
High-pressure limit rate constants are determined from the work of Zador and Miller22 using thermodynamic properties from Sarathy et al.12 Rate
a
constants are listed and expressed as k = ATb exp(−E/RT); units for A are cm3 mol−1s−1, and units for E are cal mol−1K−1.
2482
dx.doi.org/10.1021/jp211885p | J. Phys. Chem. A 2012, 116, 2475−2483

The Journal of Physical Chemistry A
Article
(6) Veloo, P. S.; Wang, Y. L.; Egolfopoulos, F. N.; Westbrook, C. K.
Combust. Flame 2010, 157, 1989−2004.
APPENDIX
■
Estimation of the High-Pressure-Limit Rate Constant for
the Decomposition of C4H9O Radical Isomers
(7) Black, G.; Curran, H. J.; Simmie, J. M.; Zhukov, V. Combust.
Flame 2010, 157, 363−373.
The high-pressure limit of the rate constants for reactions 9a,
10a, 10b, 11a, 12a, and 13 describing β-scission decomposition
were estimated on the basis of the reverse addition reaction,
described by Curran30 for similar decomposition reactions of
alkyl and alkoxy radicals. The rate constants for the addition
reactions can be estimated by assuming that addition reactions
with similar molecular interactions have equivalent reaction
rate constants. For example, the reverse of reaction 10a is the
addition of an OH radical with a 1-butene molecule, and
the rate constant for such a reaction can be estimated to be
equivalent to the addition reaction of an OH radical with a
propene molecule to form a hydroxypropyl radical product.
The rate constants for the latter reaction and other classes of
addition reactions can be determined from applying the law of
mass action to the work of Zador and Miller,22 who performed
ab initio calculations on the unimolecular pathways for the
decomposition of hydroxypropyl radicals. We made the
assumption that the rate constants calculated at 100 bar are
representative of the high-pressure limiting rate constant.
Thermodynamic properties were taken from Sarathy et al.12 in
our calculations. Table 5 presents the families of addition
reactions and the rate constants assumed for each as
determined from the work of Zador and Miller with the
thermodynamic properties from Sarathy et al.
(8) Grana, R.; Frassoldati, A.; Faravelli, T.; Niemann, U.; Ranzi, E.;
Seiser, R.; Cattolica, R.; Seshadri, K. Combust. Flame 2010, 157, 2137−
2154.
(9) Harper, M. R.; Geem, K. M. V.; Pyl, S. P.; Marin, G. B.; Green,
W. H. Combust. Flame 2011, 158, 16−41.
(10) Cook, R. D.; Davidson, D. F.; Hanson, R. K. Int. J. Chem. Kinet.
2012, DOI: 10.1002/kin.20713.
(11) Vranckx, S.; Heufer, K. A.; Lee, C.; Olivier, H.; Schill, L.; Kopp,
W. A.; Leonhard, K.; Taatjes, C. A.; Fernandes, R. X. Combust. Flame
2011, 158, 1444−1455.
(12) Sarathy, S. M.; Vranckx, S.; Yasunaga, K.; Mehl, M.; Osswald, P.;
Westbrook, C. K.; Pitz, W. J.; Kohse-Hoinghaus, K.; Fernandes, R. X.;
̈
Curran, H. J. Submitted for publication to Combust. Flame, 2011.
(13) Ranzi, E.; Dente, M.; Faravelli, T.; Pennati, G. Combust. Sci.
Technol. 1994, 95, 1−50.
́
(14) Galano, A.; Alvarez-Idaboy, J. R.; Bravo-Perez, G.; Ruiz-Santoyo,
M. E. Phys. Chem. Chem. Phys. 2002, 4, 4648−4662.
(15) Vasu, S. S.; Davidson, D. F.; Hanson, R. K.; Golden, D. M.
Chem. Phys. Lett. 2010, 497, 26−29.
(16) Zhou, C.-W.; Simmie, J. M.; Curran, H. J. Combust. Flame 2011,
158, 726−731.
(17) Pang, G. A.; Hanson, R. K.; Golden, D. M.; Bowman, C. T. Z.
Phys. Chem. 2011, 225, 1157−1178.
(18) Geem, K. M. V.; Pyl, S. P.; Marin, G. B.; Harper, M. R.; Green,
W. H. Ind. Eng. Chem. Res. 2010, 49, 10399−10420.
(19) Herbon, J. T.; Hanson, R. K.; Golden, D. M.; Bowman, C. T.
Proc. Combust. Inst. 2002, 29, 1201−1208.
(20) Sirjean, B.;et al. A high-temperature chemical kinetic model of
n-alkane oxidation. JetSurF version 1.0; September 15, 2009; http://
melchior.usc.edu/JetSurF/Version1_0/Index.html.
(21) Ritter, E. R.; Bozzelli, J. W. Int. J. Chem. Kinet. 1991, 23, 797−
778.
ASSOCIATED CONTENT
* Supporting Information
Raw data of the OH concentration time history measurements
are provided at 0.2 MHz for each data point in Tables S1 and
S2. This information is available free of charge via the Internet
at http://pubs.acs.org.
■
S
́
(22) Zador, J.; Miller, J. A. Proc. U.S. Natl. Technical Mtg. Combust.
Inst., 7th 2011, 1, 483−488.
(23) Zheng, J.; Truhlar, D. G. Phys. Chem. Chem. Phys. 2010, 12,
7782−7793.
AUTHOR INFORMATION
Corresponding Author
*E-mail: genn@stanford.edu.
Notes
■
(24) Xu, X.; Papajak, E.; Truhlar, D. G. Phys. Chem. Chem. Phys.
2012, DOI: 10.1039/C2CP23692C.
(25) Sivaramakrishnan, R.; Su, M.-C.; Michael, J. V.; Klippenstein, S.
J.; Harding, L. B.; Ruscic, B. J. Phys. Chem. A 2010, 114, 9425−9439.
(26) Klippenstein, S. J. Personal communication.
(27) Senosian, J. P.; Klippenstein, S. J.; Miller, J. A. J. Phys. Chem. A
2006, 110, 6960−6970.
(28) Miller, J. A.; Klippenstein, S. J. Phys. Chem. Chem. Phys. 2004, 6,
1192−1202.
(29) Benson, S. W. The Foundations of Chemical Kinetics; McGraw-
Hill Book Co., Inc.: New York, 1960.
(30) Curran, H. Int. J. Chem. Kinet. 2006, 38, 250−275.
(31) Zhang, P.; Klippenstein, S. J.; Law, C. K. Fall Technical Meeting
of the Eastern States Section of the Combustion Institute; 2011.
(32) Zhang, P. Personal communication.
(33) Vasudevan, V. Shock tube measurements of elementary
oxidation and decomposition reactions important in combustion
using OH, CH and NCN laser absorption. Ph.D. thesis, Stanford
University Mechanical Engineering Department, 2007.
(34) Benson, S. W.; O’Neal, H. E. NSRDS-NBS 1970, 21, 438.
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We gratefully acknowledge helpful discussions with Robert
Cook, Dr. David Davidson, Prof. Alessio Frassoldati,
Dr. Stephen Klippenstein, Dr. Bill Pitz, Dr. Mani Sarathy, Ivo
Stranic, Prof. Donald Truhlar, Dr. Judit Zador, and Dr. Peng
Zhang. This work was supported by the U.S. Department of
Energy, Office of Basic Energy Sciences, with Dr. Wade Sisk as
contract monitor, and the Combustion Energy Frontier
Research Center funded by the U.S. Department of Energy,
Office of Science, Office of Basic Energy Sciences under Award
Number DE-SC0001198.
REFERENCES
(1) Hess, G. Chem. Eng. News 2006, 84, 9.
(2) Dagaut, P.; Togbe,
(3) Dagaut, P.; Sarathy, S. M.; Thomson, M. J. Proc. Combust. Inst.
■
́
C. Fuel 2008, 87, 3313−3321.
2009, 32, 229−237.
(4) Moss, J. T.; Berkowitz, A. M.; Oehlschlaeger, M. A.; Biet, J.;
Warth, V.; Glaude, P.-A.; Battin-Leclerc, F. J. Phys. Chem. A 2008, 112,
10843−10855.
(5) Sarathy, S. M.; Thomson, M. J.; Togbe,
Mounaim-Russelle, C. Combust. Flame 2009, 156, 852−864.
́
C.; Dagaut, P.; Halter, F.;
2483
dx.doi.org/10.1021/jp211885p | J. Phys. Chem. A 2012, 116, 2475−2483