Abstract
The hydrogenation of alkenes by heterogeneous catalysts has been studied for 80 years. The foundational mechanism was proposed by Horiuti and Polanyi in 1934 and consists of three steps: (i) alkene adsorption on the surface of the hydrogenated metal catalyst, (ii) hydrogen migration to the β-carbon of the alkene with formation of a σ-bond between the metal and α-C, and finally (iii) reductive elimination of the free alkane. Hundreds of papers have appeared on the topic, along with a number of variations on the Horiuti-Polanyi mechanism. The second step is highly reversible, leading to extensive deuterium-hydrogen exchange when D2(g) is used. This paper describes the investigation of gas-phase reactions between deuterium and 1-butene using a supported palladium catalyst under ambient laboratory conditions and how the results are consistent with the Horiuti-Polanyi mechanism. An Excel spreadsheet for modeling the extent and distribution of deuteration within butane-d x is described. Interested readers could develop a laboratory or research experience based on results presented here. The results are also suitable for inclusion in an upper-division chemistry course in which organometallic chemistry or reaction mechanisms involving heterogeneous catalysts are discussed. The catalyst tubes are inexpensive and easy to construct. Analysis of the butane produced by 1H NMR and GC-MS leads to numerous conclusions in support of the Horiuti-Polanyi mechanism.
| Original language | English |
|---|---|
| Pages (from-to) | 613-619 |
| Number of pages | 7 |
| Journal | Journal of Chemical Education |
| Volume | 90 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 14 2013 |
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All Science Journal Classification (ASJC) codes
- Chemistry(all)
- Education
Cite this
Heterogeneous catalysis : The horiuti-polanyi mechanism and alkene hydrogenation. / Mattson, Bruce M.; Foster, Wendy; Greimann, Jaclyn; Hoette, Trisha; Le, Nhu; Mirich, Anne; Wankum, Shanna; Cabri, Ann; Reichenbacher, Claire; Schwanke, Erika.
In: Journal of Chemical Education, Vol. 90, No. 5, 14.05.2013, p. 613-619.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Heterogeneous catalysis
T2 - The horiuti-polanyi mechanism and alkene hydrogenation
AU - Mattson, Bruce M.
AU - Foster, Wendy
AU - Greimann, Jaclyn
AU - Hoette, Trisha
AU - Le, Nhu
AU - Mirich, Anne
AU - Wankum, Shanna
AU - Cabri, Ann
AU - Reichenbacher, Claire
AU - Schwanke, Erika
PY - 2013/5/14
Y1 - 2013/5/14
N2 - The hydrogenation of alkenes by heterogeneous catalysts has been studied for 80 years. The foundational mechanism was proposed by Horiuti and Polanyi in 1934 and consists of three steps: (i) alkene adsorption on the surface of the hydrogenated metal catalyst, (ii) hydrogen migration to the β-carbon of the alkene with formation of a σ-bond between the metal and α-C, and finally (iii) reductive elimination of the free alkane. Hundreds of papers have appeared on the topic, along with a number of variations on the Horiuti-Polanyi mechanism. The second step is highly reversible, leading to extensive deuterium-hydrogen exchange when D2(g) is used. This paper describes the investigation of gas-phase reactions between deuterium and 1-butene using a supported palladium catalyst under ambient laboratory conditions and how the results are consistent with the Horiuti-Polanyi mechanism. An Excel spreadsheet for modeling the extent and distribution of deuteration within butane-d x is described. Interested readers could develop a laboratory or research experience based on results presented here. The results are also suitable for inclusion in an upper-division chemistry course in which organometallic chemistry or reaction mechanisms involving heterogeneous catalysts are discussed. The catalyst tubes are inexpensive and easy to construct. Analysis of the butane produced by 1H NMR and GC-MS leads to numerous conclusions in support of the Horiuti-Polanyi mechanism.
AB - The hydrogenation of alkenes by heterogeneous catalysts has been studied for 80 years. The foundational mechanism was proposed by Horiuti and Polanyi in 1934 and consists of three steps: (i) alkene adsorption on the surface of the hydrogenated metal catalyst, (ii) hydrogen migration to the β-carbon of the alkene with formation of a σ-bond between the metal and α-C, and finally (iii) reductive elimination of the free alkane. Hundreds of papers have appeared on the topic, along with a number of variations on the Horiuti-Polanyi mechanism. The second step is highly reversible, leading to extensive deuterium-hydrogen exchange when D2(g) is used. This paper describes the investigation of gas-phase reactions between deuterium and 1-butene using a supported palladium catalyst under ambient laboratory conditions and how the results are consistent with the Horiuti-Polanyi mechanism. An Excel spreadsheet for modeling the extent and distribution of deuteration within butane-d x is described. Interested readers could develop a laboratory or research experience based on results presented here. The results are also suitable for inclusion in an upper-division chemistry course in which organometallic chemistry or reaction mechanisms involving heterogeneous catalysts are discussed. The catalyst tubes are inexpensive and easy to construct. Analysis of the butane produced by 1H NMR and GC-MS leads to numerous conclusions in support of the Horiuti-Polanyi mechanism.
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U2 - 10.1021/ed300437k
DO - 10.1021/ed300437k
M3 - Article
AN - SCOPUS:84877782146
VL - 90
SP - 613
EP - 619
JO - Journal of Chemical Education
JF - Journal of Chemical Education
SN - 0021-9584
IS - 5
ER -