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Linear free energy relationships in heterogeneous catalysis--13. The dehydration of aliphatic alcohols over silica-alumina. [N-butyl alcohol, sec. -butyl or isopropyl alcohol, tert. -butyl alcolol]

Journal Article:

Abstract

The dehydration of n-butyl alcohol at 120/sup 0/-166/sup 0/C, sec.-butyl or isopropyl alcohol at 100/sup 0/-145/sup 0/C, and tert.-butyl alcohol at 54/sup 0/-80/sup 0/C, over silica/alumina catalyst was zero order in alcohol at 0.01-0.1 atm, and the activation energies were 35.3, 31.7, 32.0, and 29.9 kcal/mol, respectively. The zero-order rate constants were mainly affected by the activation energies since the preexponential factors varied little except for tert.-butyl alcohol. A linear relationship was found between the activation energy or the logarithm of the zero-order rate constant and the heterolytic bond dissociation energy for the carbon-oxygen bond in alcohols D(R/sup +/OH/sup -/). The activation energy increased and the rate constant decreased with increasing D(R/sup +/OH/sup -/). The results indicate that dehydration is E1 over this catalyst, but a similar correlation was observed based on published data for dehydration over alumina, which follows an E2 mechanism, indicating that heterolytic cleavage of the C-O bond is rate-determining in both mechanisms.
Publication Date:
Jan 01, 1978
Product Type:
Journal Article
Reference Number:
EDB-84-037019
Resource Relation:
Journal Name: Bull. Chem. Soc. Jpn.; (Japan); Journal Volume: 51:6
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALUMINIUM OXIDES; CATALYTIC EFFECTS; BUTANOLS; DEHYDRATION; SILICA; ACTIVATION ENERGY; ALCOHOLS; CHEMICAL REACTION KINETICS; FREE ENTHALPY; HIGH TEMPERATURE; IONIZATION; MEDIUM TEMPERATURE; TEMPERATURE DEPENDENCE; ALUMINIUM COMPOUNDS; CHALCOGENIDES; ENERGY; HYDROXY COMPOUNDS; KINETICS; MINERALS; ORGANIC COMPOUNDS; OXIDE MINERALS; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; REACTION KINETICS; SILICON COMPOUNDS; SILICON OXIDES; THERMODYNAMIC PROPERTIES; 400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)
OSTI ID:
5272511
Research Organizations:
Univ. Tokyo
Country of Origin:
Japan
Language:
English
Other Identifying Numbers:
Journal ID: CODEN: BCSJA
Submitting Site:
HEDB
Size:
Pages: 1612-1616
Announcement Date:

Journal Article:

Citation Formats

Take, J, Matsumoto, T, and Yoneda, Y. Linear free energy relationships in heterogeneous catalysis--13. The dehydration of aliphatic alcohols over silica-alumina. [N-butyl alcohol, sec. -butyl or isopropyl alcohol, tert. -butyl alcolol]. Japan: N. p., 1978. Web. doi:10.1246/bcsj.51.1612.
Take, J, Matsumoto, T, & Yoneda, Y. Linear free energy relationships in heterogeneous catalysis--13. The dehydration of aliphatic alcohols over silica-alumina. [N-butyl alcohol, sec. -butyl or isopropyl alcohol, tert. -butyl alcolol]. Japan. doi:10.1246/bcsj.51.1612.
Take, J, Matsumoto, T, and Yoneda, Y. 1978. "Linear free energy relationships in heterogeneous catalysis--13. The dehydration of aliphatic alcohols over silica-alumina. [N-butyl alcohol, sec. -butyl or isopropyl alcohol, tert. -butyl alcolol]." Japan. doi:10.1246/bcsj.51.1612. https://www.osti.gov/servlets/purl/10.1246/bcsj.51.1612.
@misc{etde_5272511,
title = {Linear free energy relationships in heterogeneous catalysis--13. The dehydration of aliphatic alcohols over silica-alumina. [N-butyl alcohol, sec. -butyl or isopropyl alcohol, tert. -butyl alcolol]}
author = {Take, J, Matsumoto, T, and Yoneda, Y}
abstractNote = {The dehydration of n-butyl alcohol at 120/sup 0/-166/sup 0/C, sec.-butyl or isopropyl alcohol at 100/sup 0/-145/sup 0/C, and tert.-butyl alcohol at 54/sup 0/-80/sup 0/C, over silica/alumina catalyst was zero order in alcohol at 0.01-0.1 atm, and the activation energies were 35.3, 31.7, 32.0, and 29.9 kcal/mol, respectively. The zero-order rate constants were mainly affected by the activation energies since the preexponential factors varied little except for tert.-butyl alcohol. A linear relationship was found between the activation energy or the logarithm of the zero-order rate constant and the heterolytic bond dissociation energy for the carbon-oxygen bond in alcohols D(R/sup +/OH/sup -/). The activation energy increased and the rate constant decreased with increasing D(R/sup +/OH/sup -/). The results indicate that dehydration is E1 over this catalyst, but a similar correlation was observed based on published data for dehydration over alumina, which follows an E2 mechanism, indicating that heterolytic cleavage of the C-O bond is rate-determining in both mechanisms.}
doi = {10.1246/bcsj.51.1612}
journal = {Bull. Chem. Soc. Jpn.; (Japan)}
volume = {51:6}
journal type = {AC}
place = {Japan}
year = {1978}
month = {Jan}
}