Catalytic activity of systems based on coordination cyanides of copper, iron, ruthenium, and osmium in the reaction of ammonia synthesis
The purpose of the present investigation was to study the catalytic activity of systems based on cyano complexes of iron and its electronic analogs (ruthenium and osmium), and on coordination copper cyanides of the composition K/sub 2/Fe(Cu(CN)/sub 3/)/sub 2/ and KFe(Cu(CN)/sub 4/). The catalyst activities under 200 atm pressure were determined in an apparatus at space velocity of 15,000 h/sup -1/ in the temperature range 250 to 550/sup 0/C, and in an experimental plant under 300 atm pressure at 30,000 h/sup -1/ space velocity. For comparison of catalytic activity, samples of the industrial fused catalyst SA-1 and of a catalyst of the Uhde type Al/sub 4/(Fe(CN/sub 6/))/sub 3/, KAl(Fe(CN)/sub 6/) were tested at the same time. The results of the tests led to the following conclusions regarding the catalytic properties of systems based on copper cyanides. At temperatures of 325 to 400/sup 0/C the test systems had higher catalytic activity than the fused catalyst SA-1 used at present in industry. Operation at temperatures above 375/sup 0/C led to sintering of the salts tested, which caused decrease of the catalyst activity. Results show that the catalytic systems, based on potassium hexacyanoferrates, -ruthenates, and -osmates, are more active than the well-known industrial catalyst over the entire temperature range studied. The drawbacks include the presence of ballast salts, removal of which involves considerable difficulties, as the finely crystalline catalyst precipitate is a gel amorphous to x-ray diffraction, in which the individual components are distributed with a high degree of homogeneity. Moreover, preparation of the catalytic mass is complicated by its instability to oxidation by atmospheric oxygen. Catalytic systems based on hexacyanoferrates and containing ruthenium or osmium, and also ruthenium and osmium together, can be classed as catalysts of the low-temperature type.
- OSTI ID:
- 6408440
- Journal Information:
- J. Appl. Chem. USSR (Engl. Transl.); (United States), Vol. 53:9; Other Information: Translated from Zh. Prikl. Khim.; 53: No. 9, 2080-2083(Sep. 1980)
- Country of Publication:
- United States
- Language:
- English
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37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AMMONIA
SYNTHESIS
COPPER COMPLEXES
CATALYTIC EFFECTS
IRON COMPLEXES
OSMIUM COMPLEXES
POTASSIUM COMPOUNDS
RUTHENIUM COMPLEXES
CYANIDES
HIGH PRESSURE
HIGH TEMPERATURE
TEMPERATURE EFFECTS
ALKALI METAL COMPOUNDS
COMPLEXES
HYDRIDES
HYDROGEN COMPOUNDS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
TRANSITION ELEMENT COMPLEXES
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400201 - Chemical & Physicochemical Properties