Table 1 Reaction Gibbs free energy barrier (∆Gact, kJ mol−1), pre-exponential factor(A, s−1), and rate coefficient (k, s−1) at 473 K of the forward (f) and reverse reactions (r) for the elementary step associated with the eight ethene production routes

From: Observation of an oxonium ion intermediate in ethanol dehydration to ethene on zeolite

 

Elementary step

∆Gact(f)

∆Gact(r)

A f

k f

A r

k r

Route 1

\({\rm{C}}\mathop { \leftrightarrow }\limits^{{\rm{TS4}}} {\rm{DEE}}{\rm{.H}}_2{\rm{O}} \ast\) (4)

129.0

79.4

6.43 × 1011

5.54 × 10−2

4.20 × 1012

1.70 × 104

\({\rm{D}}\mathop { \leftrightarrow }\limits^{{\rm{TS6}}} {\rm{TEO}}{\rm{.H}}_2{\rm{O}} \ast\) (6)

94.1

65.0

1.19 × 1013

3.95 × 102

8.68 × 1011

6.45 × 105

\({\rm{TEO}} \ast \mathop { \leftrightarrow }\limits^{{\rm{TS7}}} {\rm{Ethoxy}}{\rm{.DEE}} \ast {\rm{(7)}}\)

81.7

66.6

1.29 × 1012

9.61 × 103

9.33 × 1011

4.38 × 105

\({\rm{Ethoxy}}\mathop { \leftrightarrow }\limits^{{\rm{TS8}}} {\rm{Ethene}} \ast\) (8)

107.6

75.3

1.32 × 1013

1.30 × 101

1.91 × 1011

4.74 × 104

Route 2

\({\rm{C}}\mathop { \leftrightarrow }\limits^{{\rm{TS4}}} {\rm{DEE}}{\rm{.H}}_2{\rm{O}} \ast\) (4)

129.0

79.4

6.43 × 1011

5.54 × 10−2

4.20 × 1012

1.70 × 104

\({\rm{D}}\mathop { \leftrightarrow }\limits^{{\rm{TS6}}} {\rm{TEO}}{\rm{.H}}_2{\rm{O}} \ast\) (6)

94.1

65.0

1.19 × 1013

3.95 × 102

8.68 × 1011

6.45 × 105

\({\rm{TEO}} \ast \mathop { \leftrightarrow }\limits^{{\rm{TS13}}} {\rm{Ethene}}{\rm{.DEE}} \ast {\rm{(13)}}\)

127.7

78.4

2.23 × 1013

7.81 × 10−2

9.32 × 109

2.17 × 104

Route 3

\({\rm{C}}\mathop { \leftrightarrow }\limits^{{\rm{TS4}}} {\rm{DEE}}{\rm{.H}}_2{\rm{O}} \ast\) (4)

129.0

79.4

6.43 × 1011

5.54 × 10−2

4.20 × 1012

1.70 × 104

\({\rm{DEE}} \ast \mathop { \leftrightarrow }\limits^{{\rm{TS12}}} {\rm{Ethoxy}}{\rm{.EtOH}} \ast {\rm{(12)}}\)

155.9

78.2

7.12 × 1012

6.01 × 10−5

5.11 × 1011

2.26 × 104

\({\rm{Ethoxy}}\mathop { \leftrightarrow }\limits^{{\rm{TS8}}} {\rm{Ethene}} \ast\) (8)

107.6

75.3

1.32 × 1013

1.30 × 101

1.91 × 1011

4.74 × 104

Route 4

\({\rm{C}}\mathop { \leftrightarrow }\limits^{{\rm{TS4}}} {\rm{DEE}}{\rm{.H}}_2{\rm{O}} \ast\) (4)

129.0

79.4

6.43 × 1011

5.54 × 10−2

4.20 × 1012

1.70 × 104

\({\rm{DEE}} \ast \mathop { \leftrightarrow }\limits^{{\rm{TS11}}} {\rm{Ethene}}{\rm{.EtOH}} \ast {\rm{(11)}}\)

136.1

58.9

1.03 × 1014

9.24 × 10−3

5.11 × 1011

3.06 × 106

Route 5

\({\rm{A}}\mathop { \leftrightarrow }\limits^{{\rm{TS9}}} {\rm{Ethoxy}}{\rm{.H}}_2{\rm{O}} \ast {\rm{(9)}}\)

146.3

69.8

6.75 × 1013

6.81 × 10−4

4.79 × 1012

1.91 × 105

\({\rm{Ethoxy}}\mathop { \leftrightarrow }\limits^{{\rm{TS8}}} {\rm{Ethene}} \ast\) (8)

107.6

75.3

1.32 × 1013

1.30 × 101

1.91 × 1011

4.74 × 104

Route 6

\({\rm{A}}\mathop { \leftrightarrow }\limits^{{\rm{TS10}}} {\rm{Ethene}}{\rm{.H}}_2{\rm{O}} \ast {\rm{(10)}}\)

171.8

103.3

4.28 × 1013

1.04 × 10−6

2.96 × 1010

3.81 × 101

Route 7

\({\rm{E}}\mathop { \leftrightarrow }\limits^{{\rm{TS15}}} {\rm{Ethene}}{\rm{.2H}}_2{\rm{O}} \ast\) (15)

184.8

64.7

1.15 × 1014

3.89 × 10−8

1.71 × 1011

6.98 × 105

Route 8

\({\rm{B}}\mathop { \leftrightarrow }\limits^{{\rm{TS16}}} {\rm{Ethene}}{\rm{.H}}_2{\rm{O}}{\rm{.EtOH}} \ast {\rm{(16)}}\)

145.2

119.2

5.37 × 1013

9.01 × 10−4

1.89 × 1010

6.76 × 10−1

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