Microwave Activation of Homogeneous and Heterogeneous Catalytic Reactions

[img]PDF - Authorized users only
Language: English
41Kb
Title:Microwave Activation of Homogeneous and Heterogeneous Catalytic Reactions
Creators:
Hájek, Milan
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 62, 2, pp. 347-354
Uncontrolled Keywords:Alkylation of secondary amines, NaY zeolite as catalyst, Catalysis, Addition of halo compounds, Microwave activation

Abstract

Microwave heating was applied in homogeneous and in heterogeneous reactions and the results were compared from the point of view of activation of chemical reactions. Reactions including the addition of halo compounds to alkenes catalyzed by copper and ruthenium complexes in different solvents and NaY zeolite catalyzed alkylation of secondary amine in the absence of solvent were studied as model reactions to compare possibilities of microwave activation of reactants and catalysts. Rate enhancement of over one order of magnitude in homogeneous reactions was caused mainly by thermal dielectric heating effect which resulted from the effective coupling of microwaves to polar solvents. Activation of reactants and catalysts was very low if any. In heterogeneously catalyzed alkylation reactions highly efficient activation of zeolite catalyst was recorded. The results indicated that the best reaction conditions were in experiments when both activation of catalyst and performance of reaction were carried out under microwave conditions. Rate enhancement was most probably caused by "hot spots" or by "selective heating" of active sites. In both homogeneous and heterogeneous reactions non-thermal activation (specific effect) was excluded.

Title:Microwave Activation of Homogeneous and Heterogeneous Catalytic Reactions
Creators:
Hájek, Milan
Uncontrolled Keywords:Alkylation of secondary amines, NaY zeolite as catalyst, Catalysis, Addition of halo compounds, Microwave activation
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:62
Number:2
Page Range:pp. 347-354
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19970347UNSPECIFIED
ID Code:1121
Item Type:Article
Deposited On:06 Feb 2009 17:06
Last Modified:06 Feb 2009 16:06

Citation

Hájek, Milan (1997) Microwave Activation of Homogeneous and Heterogeneous Catalytic Reactions. Collection of Czechoslovak Chemical Communications, 62 (2). pp. 347-354. ISSN 0010-0765

Repository Staff Only: item control page