Evidence for the presence of alternative mechanisms in the oxidation of cyclohexanone to adipic acid with oxygen, catalysed by Keggin polyoxometalates

被引：47

作者：

Cavani, Fabrizio ^{[1
]}

Ferroni, Laura ^{[1
]}

Frattini, Alessandra ^{[1
]}

Lucarelli, Carlo ^{[1
]}

Mazzini, Andrea ^{[1
]}

Raabova, Katerina ^{[1
]}

Alini, Stefano ^{[2
]}

Accorinti, Pasquale ^{[2
]}

Babini, Pierpaolo ^{[2
]}

机构：

[1] Univ Bologna, Alma Mater Studiorum, Dipartimento Chim Ind & Mat, I-40136 Bologna, Italy

[2] Radici Chim SpA, I-20190 Novara, Italy

来源：

APPLIED CATALYSIS A-GENERAL | 2011年 / 391卷 / 1-2期

关键词：

Adipic acid; Cyclohexanone oxidation; Keggin polyoxometalates; Reaction mechanism; Redox mechanism; Autoxidation; LIQUID-PHASE OXIDATION; HETEROPOLY ACIDS; MOLECULAR-OXYGEN; METAL-COMPLEXES; DIOXYGEN; AUTOXIDATION; CLEAVAGE; HYDROCARBONS; KETONES; AIR;

D O I：

10.1016/j.apcata.2010.04.032

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

This report deals with the results of a study on the oxidation of cyclohexanone to adipic acid with air, catalysed by Keggin-type polyoxometalates of composition H3+xPMo12-xVxO40 (x=1 and 2), which was carried out in a semi-continuous stirred-tank reactor. It was found that when conducted in the presence of a water-only solvent, the reaction proceeds with a redox mechanism, in which the step of reoxidation of the reduced POM by oxygen is rate limiting. When, however, the reaction was carried out with an acetic acid co-solvent, a radical-chain autoxidation mechanism prevailed, especially when very low amounts of catalyst were used. Autoxidation overlapped with the redox mechanism when the catalyst-to-cyclohexanone ratio was increased. Moreover, the composition of the polyoxometalate, that is, the number of V atoms per Keggin unit, affected the relative importance of the two mechanisms. The selectivity to adipic acid achieved was a function of the reaction mechanism, but also was affected by cyclohexanone conversion, due to the presence of a complex reaction network (C) 2010 Elsevier B.V. All rights reserved.

引用

页码：118 / 124

页数：7

共 37 条

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