Isao Matsuzaki, R. Burwell
Mar 1, 1963
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0
Influential Citations
2
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Journal
The Journal of Physical Chemistry
Abstract
Reaction of hydrogen and deuterium with 1-hexene was investigated in a vapor phase, flow reactor on copper-chromium oxide catalyst at temperatures of from 50 to 150 deg . The catalyst was pre-treated with hydrogen at 325 deg , There are three primary reactions, hydrogenation, isomerization to trans- and cis- 2-hexene which appear in a ratio of about 10, and formation of isotopically exchanged 1-hexene. The last reaction is the fastest and, as shown by n.m.r., it involves almost exclusively exchange at carbon atom-2 to form 1-hexene-2-d. The activation energy for isomerization is about 5 kcal greater than that for hydrogenation. The rates of the two reactions are equal at about 90 deg . At 60 deg , presence of 1-hexene almost completely inhibits hydrogenation of 2-hexene but it does not inhibit isomerization of 2- to 3-hexene. The isotopic distribution pattern of the hexene formed at low conversions seems to result from the addition of two (H,D) atoms to a mixture of 1-hexene and 1-hexene-2-d formed by previous exchange. Thus, during the course of hydrogenation, there seems to be little tendency for reversion of diadsorbed hexane to monoadsorbed. Isotopic distribution patterns for trans-2-hexene are presented and difficulties in the application ofmore » the Horiuti- Polanyi mechanism to olefin isomerization and exchange are discussed.« less