ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The kinetics of the catalytic hydration of acetylene to acetaldehyde in the gas-phase by incorporation of catalytic metal ions on molecular sieves has been studied in a differential reactor. The main product was acetaldehyde besides of small amounts of crotonaldehyde and acetic acid. The catalysts [cadmium(II)-, zinc(II)-, copper(II)- and silver(I)-13 X-molecular sieves] were deactivated at a rate proportional to the square of the hydration rate. The initial hydration rate calculated on the basis of this relation was first order in the acetylene concentration. Starting rate of hydration and rate of deactivation increase with increasing concentration of metal ions on the sieve. The temperature dependence of the rate follows the law of Arrhenius The activation energies of hydration and deactivation, respectively, were calculated. Pore diffusion is a limiting factor. The poison is homogeneously deposited on the catalyst and weakly adsorbed, as it is shown by the criterion of Wheeler. The rate of deactivation decreases with increasing water/acetylene ratio. The deactivation rate which is due to deposition of polymerised acetylene and/or acetaldehyde, is slow with zinc and cadmium catalysts, and more rapid with copper and silver catalysts.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19740570218
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