Supported Ammonia Synthesis Catalysts Based on Potassium Derivatives of Anionic Ruthenium, Osmium and Iron Carbonyl Clusters. The First Catalysts on Carbon Support Exhibiting Activity in Ammonia Synthesis in the Absence of a Specially Added Electron Promoter Full article
Journal |
Journal of Molecular Catalysis A: Chemical
ISSN: 1381-1169 |
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Output data | Year: 1999, Volume: 139, Number: 2-3, Pages: 219-225 Pages count : 7 DOI: 10.1016/S1381-1169(98)00198-8 | ||||||
Tags | Ammonia synthesis, Anionic metal carbonyl clusters, Iron, Metallic potassium, Osmium, Ruthenium, Supported catalysts | ||||||
Authors |
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Affiliations |
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Funding (1)
1 | European Commission | ERBCHRXCT 930147 |
Abstract:
The first catalysts on carbon support exhibiting activity in ammonia synthesis in the absence of a specially added electron promoter have been found. The catalysts were prepared by depositing K2[Ru4(CO)13], K2[Os3(CO)11] and K2[Fe2(CO)8] from THF solutions on the original graphite-like active carbon `Sibunit' followed by drying of the samples obtained at 20°C in vacuum. The highest efficiency is displayed by the K2[Ru4(CO)13] catalyst which is active in ammonia synthesis starting from 250°C (1 atm). On passing from K2[Ru4(CO)13] to K2[Os3(CO)11] and then to K2[Fe2(CO)8] the rate of ammonia synthesis lowers. The replacement of `Sibunit' by usual commercial active carbon SKT results in a sharp decrease in activity and stability of the catalysts. An introduction of metallic potassium into the catalysts on `Sibunit' carbon accelerates strongly the process of ammonia synthesis. A study of the K2[Ru4(CO)13]+K and K2[Fe2(CO)8]+K catalysts has shown that at constant transition metal and carbon contents in the system, the activity of both catalysts passes through a maximum with an increase in potassium quantity, in the case of ruthenium the position of the maximum being reached at considerably less amounts of potassium in the sample than in the case of iron. The K2[Ru4(CO)13]+K catalyst is much less active than the K2[Fe2(CO)8]+K catalyst at 200°C but considerably exceeds it in activity at higher temperatures (250–350°C).
Cite:
Yunusov S.M.
, Kalyuzhnaya E.S.
, Mahapatra H.
, Puri V.K.
, Likholobov V.A.
, Shur V.B.
Supported Ammonia Synthesis Catalysts Based on Potassium Derivatives of Anionic Ruthenium, Osmium and Iron Carbonyl Clusters. The First Catalysts on Carbon Support Exhibiting Activity in Ammonia Synthesis in the Absence of a Specially Added Electron Promoter
Journal of Molecular Catalysis A: Chemical. 1999. V.139. N2-3. P.219-225. DOI: 10.1016/S1381-1169(98)00198-8 WOS Scopus РИНЦ
Supported Ammonia Synthesis Catalysts Based on Potassium Derivatives of Anionic Ruthenium, Osmium and Iron Carbonyl Clusters. The First Catalysts on Carbon Support Exhibiting Activity in Ammonia Synthesis in the Absence of a Specially Added Electron Promoter
Journal of Molecular Catalysis A: Chemical. 1999. V.139. N2-3. P.219-225. DOI: 10.1016/S1381-1169(98)00198-8 WOS Scopus РИНЦ
Dates:
Submitted: | Jun 2, 1997 |
Accepted: | May 18, 1998 |
Published online: | Jan 26, 1999 |
Published print: | Mar 5, 1999 |
Identifiers:
Web of science | WOS:000078361700012 |
Scopus | 2-s2.0-0033525417 |
Elibrary | 13329728 |
Chemical Abstracts | 1999:45718 |
Chemical Abstracts (print) | 130:101174 |
OpenAlex | W1985549428 |