Blocking of the silver catalyst surface in the conversion of ethylene to ethylene oxide

1977 ◽  
Vol 6 (3) ◽  
pp. 409-415 ◽  
Author(s):  
Sh. L. Guseinov ◽  
I. T. Frolkina ◽  
L. A. Vasilevich ◽  
A. K. Avetisov ◽  
A. I. Gel'bstein
Keyword(s):  
Ethylene Oxide ◽  
Catalyst Surface ◽  
Silver Catalyst

THE SILVER CATALYZED OXIDATION OF ETHYLENE: I. SLOW PROCESSES ON THE CATALYST SURFACE

1954 ◽  
Vol 32 (4) ◽  
pp. 388-398 ◽  
Author(s):  
A. Orzechowski ◽  
K. E. MacCormack
Keyword(s):  
Ethylene Oxide ◽  
Reaction Temperature ◽  
Catalyst Surface ◽  
Flow System ◽  
Catalyst Activity ◽  
Reference State ◽  
Silver Catalyst ◽  
Kinetic Measurements ◽  
Catalyzed Oxidation ◽  
Oxygen Atoms

In the silver catalyzed oxidation of ethylene or ethylene oxide (EtO), the silver catalyst activity measured under constant standard conditions in a flow system was found to be dependent on the conditions of previous catalyst treatment such as reaction temperature and reactant composition. The results are explained on the basis of slow establishment of equilibrium respecting fixation of stably sorbed oxygen atoms and surface products of oxidation. It is emphasized that in view of the slow processes observed, the kinetic measurements must be punctuated by frequent stabilizing check runs in order to maintain the catalyst in the same reference state.

Origin of enhanced ethylene oxide selectivity by Cs-promoted silver catalyst

2017 ◽  
Vol 441 ◽  
pp. 92-99 ◽  
Author(s):  
Dongmei Ren ◽  
Haoxiang Xu ◽  
Jianwei Li ◽  
Jinbing Li ◽  
Daojian Cheng
Keyword(s):  
Ethylene Oxide ◽  
Silver Catalyst

Microreactors as tools in kinetic investigations: Ethylene oxide formation on silver catalyst

2013 ◽  
Vol 87 ◽  
pp. 306-314 ◽  
Author(s):  
Tapio Salmi ◽  
José Hernández Carucci ◽  
Mauricio Roche ◽  
Kari Eränen ◽  
Johan Wärnå ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Silver Catalyst ◽  
Oxide Formation ◽  
Kinetic Investigations

The role played by an iodine-containing promoter in the formation of active polycrystalline silver catalyst surface

2009 ◽  
Vol 83 (7) ◽  
pp. 1088-1093
Author(s):  
V. S. Mal’kov ◽  
A. S. Knyazev ◽  
O. V. Vodyankina ◽  
I. K. Pak ◽  
E. V. Chernikov ◽  
...  
Keyword(s):  
Catalyst Surface ◽  
Silver Catalyst ◽  
Polycrystalline Silver

scholarly journals The mechanism of the catalytic oxidation of ethylene - II. Reactions between ethylene, etc. and chemisorbed oxygen monolayers

1946 ◽  
Vol 188 (1012) ◽  
pp. 105-122 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Ethylene Oxide ◽  
Low Temperatures ◽  
Adsorbed Oxygen ◽  
Silver Catalyst ◽  
Time Curve ◽  
Chemisorbed Oxygen ◽  
Pressure Time ◽  
Adsorbed Oxygen Atom ◽  
Kinetics Of

Experiments have been carried out at temperatures of 263° C and higher between oxygen adsorbed as atoms on the silver catalyst, and ethylene, ethylene oxide and acetaldehyde. The course of reaction was followed by measuring the change in pressure, and analyses of the products were made by micro-fractionation of the gases at low temperatures. In the reaction of ethylene with an oxygen-covered catalyst, the absence of an induction period in the pressure-time curve showed that oxidation of ethylene to carbon dioxide and water by a route not through ethylene oxide is possible. The reaction of acetaldehyde with the oxygenated catalyst was too fast to measure. The reactions of ethylene oxide were found to be complex, and reaction occurred both with the oxygenated and the clean catalyst. On a clean catalyst, ethylene oxide was simultaneously isomerized to acetaldehyde and converted back to ethylene and adsorbed oxygen; the acetaldehyde and adsorbed oxygen then reacted to form carbon dioxide and water. Both ethylene oxide and acetaldehyde, but not ethylene, were adsorbed with decomposition to form a non-volatile layer on the catalyst. This was composed of carbon, hydrogen and possibly oxygen, combined in indefinite and varying proportions. The kinetics of the reaction between ethylene and the adsorbed oxygen layer were measured. Throughout the course of any one reaction, the rate of oxidation to carbon dioxide was proportional to the square of the concentration of adsorbed oxygen, but the velocity constant depended on the initial concentration. The apparent energy of activation was 10 kcal. It is thought that when ethylene reacts with a single adsorbed oxygen atom, ethylene oxide is produced, and that with a pair of adsorbed oxygen atoms, intermediates such as formaldehyde are produced which react rapidly to form carbon dioxide and water.

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