Experimental investigation of the low temperature
oxidation of the five isomers of hexane
Zhandong WANG1,2, Olivier HERBINET1, Zhanjun Cheng2, Benoit HUSSON1, René Fournet1, Fei QI2, Frédérique
BATTIN-LECLERC1
1
Laboratoire Réactions et Génie des Procédés, Nancy Université, CNRS UPR 3349,
BP 20451, 1 rue Grandville, 54000 Nancy, France
2
National Synchrotron Radiation Laboratory, University of Science and Technology of China,
Hefei, Anhui 230029, P. R. China.
Supplemental data
I. Comparison of GC and SVUV PIMS data for n-hexane, 2-methyl-pentane and
2,2-dimethyl-butane.
II. Mass spectra of cyclic ethers which were not in databases.
III. Structures of the parent cations obtained from the ionization of
ketohydroperoxydes and diones.
I. Comparison of GC and SVUV PIMS data for n-hexane, 2-methyl-pentane and 2,2dimethyl-butane.
1. Comparison for n-hexane
-3
Mole Fraction
25x10
n-Hexane
20
15
10
5
0
400
500
600
700
Temperature (K)
Mole Fraction
0.20
800
Oxygen
0.15
0.10
0.05
0.00
400
500
600
700
Temperature (K)
800
Figure S1: Comparison of mole fraction profiles obtained using gas chromatography ( ) and SVUV-PIMS (×)
for n-hexane and oxygen (fuel inlet mole fraction of 0.02). The signals recorded at 11 eV for m/z 86 and at
16.6 eV for m/z 32 were used for the quantification of n-hexane and oxygen, respectively.
-3
-3
10x10
Carbon Monoxide
(SVUV PIMS data were obtained
from the signal at 16.6 eV for m/z 28)
40
Mole Fraction
Mole Fraction
50x10
30
20
10
0
500
600
700
Temperature (K)
4
2
800
-3
400
500
600
700
Temperature (K)
800
-3
10x10
10x10
Methanol
(SVUV PIMS data were obtained
from the signal at 11 eV for m/z 32)
8
Mole Fraction
Mole Fraction
6
0
400
6
4
2
0
Acetaldehyde
(SVUV PIMS data were obtained
from the signal at 10.5 eV for m/z 44)
8
6
4
2
0
400
500
600
700
Temperature (K)
800
-3
1.5
400
500
600
700
Temperature (K)
800
-6
800x10
Acetic Acid
(SVUV PIMS data were obtained
from the signal at 11 eV for m/z 60)
Mole Fraction
2.0x10
Mole Fraction
Carbon Dioxide
(SVUV PIMS data were obtained
from the signal at 16.6 eV for m/z 44)
8
1.0
0.5
0.0
600
Propanoic Acid
(SVUV PIMS data were obtained
from the signal at 11 eV for m/z 74)
400
200
0
400
500
600
700
Temperature (K)
800
400
500
600
700
Temperature (K)
800
Figure S2: Comparison of mole fraction profiles obtained using gas chromatography ( ) and SVUV-PIMS (×)
for oxygenated reaction products (fuel inlet mole fraction of 0.02).
-3
0.8
-3
10x10
Methane
(SVUV PIMS data were obtained
from the signal at 16.6 eV for m/z 16)
Mole Fraction
Mole Fraction
1.0x10
0.6
0.4
0.2
0.0
500
600
700
Temperature (K)
2
400
1.6x10
Propene
(SVUV PIMS data were obtained
from the signal at 10 eV for m/z 42)
Mole Fraction
Mole Fraction
4
800
-3
1.5
6
0
400
2.0x10
Ethylene
(SVUV PIMS data were obtained
from the signal at 11 eV for m/z 28)
8
1.0
0.5
500
600
700
Temperature (K)
800
-3
1.2
Butene isomers
(SVUV PIMS data were obtained
from the signal at 10.5 eV for m/z 56)
0.8
0.4
0.0
0.0
400
500
600
700
Temperature (K)
800
400
500
600
700
Temperature (K)
800
Figure S3: Comparison of mole fraction profiles obtained using gas chromatography ( ) and SVUV-PIMS (×)
for small hydrocarbon reaction products (fuel inlet mole fraction of 0.02).
2. Comparison for 2-methyl-pentane
-3
Mole Fraction
25x10
2-methyl-pentane
20
15
10
5
0
500
600
700
Temperature (K)
Mole Fraction
0.20
800
Oxygen
0.15
0.10
0.05
0.00
500
600
700
Temperature (K)
800
Figure S4: Comparison of mole fraction profiles obtained using gas chromatography ( ) and SVUV-PIMS (×)
for 3-methyl-pentane and oxygen (fuel inlet mole fraction of 0.02). The signals recorded at 11 eV for m/z 86
and at 16.6 eV for m/z 32 were used for the quantification of 2-methyl-pentane and oxygen, respectively.
-3
-3
50x10
8
Mole Fraction
(SVUV PIMS data were obtained
from the signal at 16.6 eV for m/z 28)
40
Mole Fraction
10x10
Carbon Monoxide
30
20
10
6
4
2
0
0
500
600
700
Temperature (K)
800
-3
6
500
600
700
Temperature (K)
800
-3
5x10
Methanol
(SVUV PIMS data were obtained
from the signal at 11 eV for m/z 32)
Mole Fraction
Mole Fraction
8x10
Carbon Dioxide
(SVUV PIMS data were obtained
from the signal at 16.6 eV for m/z 44)
4
2
0
4
Acetaldehyde
(SVUV PIMS data were obtained
from the signal at 10.5 eV for m/z 44)
3
2
1
0
500
600
700
Temperature (K)
800
500
600
700
Temperature (K)
800
Figure S5: Comparison of mole fraction profiles obtained using gas chromatography ( ) and SVUV-PIMS (×)
for oxygenated reaction products (2-methyl-pentane inlet mole fraction of 0.02).
-6
400
-3
1.0x10
Methane
(SVUV PIMS data were obtained
from the signal at 16.6 eV for m/z 16)
Mole Fraction
Mole Fraction
500x10
300
200
100
0
600
700
Temperature (K)
0.4
0.2
500
600
700
Temperature (K)
800
-3
1.6x10
Propene
(SVUV PIMS data were obtained
from the signal at 10 eV for m/z 42)
Mole Fraction
Mole Fraction
0.6
800
-3
0.8
Ethylene
(SVUV PIMS data were obtained
from the signal at 11 eV for m/z 28)
0.0
500
1.0x10
0.8
0.6
0.4
0.2
0.0
1.2
Iso-butene
(SVUV PIMS data were obtained
from the signal at 10.5 eV for m/z 56)
0.8
0.4
0.0
500
600
700
Temperature (K)
800
500
600
700
Temperature (K)
800
Figure S6: Comparison of mole fraction profiles obtained using gas chromatography ( ) and SVUV-PIMS (×)
for small hydrocarbon reaction products (2-methyl-pentane inlet mole fraction of 0.02).
3. Comparison for 2,2-dimethyl-butane
-3
Mole Fraction
25x10
2,2-dimethyl-butane
20
15
10
5
0
500
600
700
Temperature (K)
Mole Fraction
0.20
800
Oxygen
0.15
0.10
0.05
0.00
500
600
700
Temperature (K)
800
Figure S7: Comparison of mole fraction profiles obtained using gas chromatography ( ) and SVUV-PIMS (×)
for 2,2-dimethyl-butane and oxygen (fuel inlet mole fraction of 0.02). The signals recorded at 11 eV for m/z
86 and at 16.6 eV for m/z 32 were used for the quantification of 2,2-dimethyl-butane and oxygen,
respectively.
-3
-3
2.0x10
Carbon Monoxide
(SVUV PIMS data were obtained
from the signal at 16.6 eV for m/z 28)
40
Mole Fraction
Mole Fraction
50x10
30
20
10
0
1.5
1.0
0.5
0.0
500
600
700
Temperature (K)
800
-3
1.5
500
600
700
Temperature (K)
800
-3
2.0x10
Methanol
(SVUV PIMS data were obtained
from the signal at 11 eV for m/z 32)
Mole Fraction
2.0x10
Mole Fraction
Carbon Dioxide
(SVUV PIMS data were obtained
from the signal at 16.6 eV for m/z 44)
1.0
0.5
0.0
1.5
Acetaldehyde
(SVUV PIMS data were obtained
from the signal at 10.5 eV for m/z 44)
1.0
0.5
0.0
500
600
700
Temperature (K)
800
500
600
700
Temperature (K)
800
Figure S8: Comparison of mole fraction profiles obtained using gas chromatography ( ) and SVUV-PIMS (×)
for oxygenated reaction products (2,2-dimethyl-butane inlet mole fraction of 0.02).
-3
6
-3
8x10
Methane
(SVUV PIMS data were obtained
from the signal at 16.6 eV for m/z 16)
Mole Fraction
Mole Fraction
8x10
4
2
0
Ethylene
(SVUV PIMS data were obtained
from the signal at 11 eV for m/z 28)
6
4
2
0
500
600
700
Temperature (K)
800
500
600
700
Temperature (K)
800
-6
Mole Fraction
50x10
40
Propene
(SVUV PIMS data were obtained
from the signal at 10 eV for m/z 42)
30
20
10
0
500
600
700
Temperature (K)
800
Figure S9: Comparison of mole fraction profiles obtained using gas chromatography ( ) and SVUV-PIMS (×)
for small hydrocarbon reaction products (2,2-dimethyl-butane inlet mole fraction of 0.02).
It was not possible to quantify iso-butene from the SVUV-PIMS data because the signal of iso-butene is
masked by the large signal of the fragment at m/z 56 coming from the decomposition of the fuel molecular
ion.
II. Mass spectra of cyclic ethers which were not in databases.
Relative Intensity
50x10
3
2-ethyl-tetrahydrofuran
40
O
30
20
10
0
0
20
40
60
m/z
80
100
120
Figure S10: Mass spectrum of 2-ethyl-tetrahydrofuran (detected in the oxidation of n-hexane).
Relative Intensity
16x10
3
2-ethyl,4-methyl-oxetane
O
12
8
4
0
0
20
40
60
m/z
80
100
120
Figure S11: Mass spectrum of 2-ethyl,4-methyl-oxetane (detected in the oxidation of n-hexane).
Relative Intensity
10000
3-propyl-oxetane
8000
6000
O
4000
2000
0
0
20
40
60
m/z
80
100
120
Figure S12: Mass spectrum of 3-propyl-oxetane (detected in the oxidation of 2-methyl-pentane).
Relative Intensity
14x10
3
12
10
2,3-dimethyl-tetrahydrofuran
O
8
6
4
2
0
0
20
40
60
m/z
80
100
120
Figure S13: Mass spectrum of 2,3-dimethyl-tetrahydrofuran (detected in the oxidation of 3-methyl-pentane).
Relative Intensity
3000
4-methyl-tetrahydropyran
2500
O
2000
1500
1000
500
0
20
40
60
80
100
m/z
Figure S14: Mass spectrum of 4-methyl-tetrahydrofuran (detected in the oxidation of 3-methyl-pentane).
Relative Intensity
60x10
3
3,3-methyl,ethyl-oxetane
50
O
40
30
20
10
0
0
20
40
60
m/z
80
100
120
Figure S15: Mass spectrum of 3,3-methyl,ethyl-oxetane (detected in the oxidation of 2,2-dimethyl-butane).
Relative Intensity
600x10
3
2,3,3-trimethyl-oxetane
500
O
400
300
200
100
0
0
20
40
60
m/z
80
100
120
Figure S16: Mass spectrum of 2,3,3-trimethyl-oxetane (detected in the oxidation of 2,2-dimethyl-butane).
Relative Intensity
500x10
3
3,3-dimethyl-tetrahydrofuran
400
O
300
200
100
0
0
20
40
60
m/z
80
100
120
Figure S17: Mass spectrum of 3,3-dimethyl-tetrahydrofuran (detected in the oxidation of 2,2-dimethylbutane).
III. Structures of the parent cations obtained from the ionization of
ketohydroperoxydes and diones.
Table S1: Structures of the parent cation and calculated ionization energies of ketohydroperoxides detected
during the oxidation of hexane isomers.
Name
Structure of the parent cation
Calculated
ionization energy (eV)
From n-hexane
4-hydroperoxyhexan-2-one
9.20
5-hydroperoxyhexan-3-one
9.50
1-hydroperoxyhexan-3-one
9.53
3-hydroperoxyhexanal
9.49
From 2-methyl-pentane
4-methyl-
8.87
4-hydroperoxypentan-2-one
4-methyl3-hydroperoxypentanal
9.53
4-methyl1-hydroperoxypentan-3-one
8.95
2-methyl-3-hydroperoxypentanal
9.10
2-methyl-1-hydroperoxy pentan-3one
9.36
From 3-methyl-pentane
3-methyl-3-hydroperoxy –pentanal
9.21
3-methyl-4-hydroperoxy –pentan-2one
9.18
2-ethyl-3-hydroperoxybutanal
9.04
3-(hydroperoxymethyl)pentan-2-one
9.26
From 2,2-dimethyl-butane
2-(hydroperoxymethyl)-2methylbutanal
9.12
2,2-dimethyl-3-hydroperoxybutanal
9.53
3,3-dimethyl-4-hydroperoxybutanone
9.33
Table S2: Structures and calculated ionization energies of diones detected during the oxidation of hexane
isomers.
Name
Structure of the parent cation
Calculated
ionization energy (eV)
From n-hexane
2,4-hexadione
9.31
3-oxo-hexanal
9.37
From 2-methyl-pentane
4-methyl-3-oxo-pentanal
9.26
2-methyl-3-oxo-pentanal
9.26
From 3-methyl-pentane
3-methyl-2,4-pentadione
9.16
2-ethyl-3-oxobutanal
9.23
From 2,2-dimethyl-butane
2-ethyl-2methylpropanedial
9.31
2,2-dimethyl-3-oxobutanal
9.13