New Ammonia Synthesis Catalysts Based on Supported Potassium Carbonyl Ruthenates as Precursors of Catalytically Active Ruthenium Particles and Potassium Promoter Full article
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Journal of Molecular Catalysis A: Chemical
ISSN: 1381-1169 |
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| Output data | Year: 2004, Volume: 219, Number: 1, Pages: 149-153 Pages count : 5 DOI: 10.1016/j.molcata.2004.04.031 | ||||
| Tags | Ammonia synthesis, Metallic potassium, Potassium carbonyl metallates, Ruthenium, Supported catalysts | ||||
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| Affiliations |
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Funding (1)
| 1 | Russian Foundation for Basic Research | 02-03-32681 |
Abstract:
New supported “single-component” ruthenium catalysts for ammonia synthesis are reported. For preparation of the catalysts, various potassium carbonyl ruthenates such as K2[Ru6(CO)18] (K:Ru=1:3), K4[Ru4(CO)12] (K:Ru=1:1), K6[Ru6(CO)16] (K:Ru=1:1), K6[Ru4(CO)11] (K:Ru=1.5:1) and K2[Ru(CO)4] (K:Ru=2:1) were used as precursors of both catalytically active ruthenium particles and potassium promoter while graphite-like carbon “Sibunit” was utilized as a support. The studied catalysts have been compared in their activity with the previously described K2[Ru4(CO)13]-based catalyst (K:Ru=1:2) on “Sibunit”. It has been established that the rate of the ammonia synthesis at 300 °C over these catalysts increases with the increase in the K:Ru ratio in the starting carbonyl metallate, reaching a maximum in the case of the K6[Ru4(CO)11]-based sample. On further enhancement in the K:Ru ratio, i.e. when the K2[Ru(CO)4] catalyst is used, the rate of the ammonia formation noticeably diminishes. The activity of the K2[Ru(CO)4]-based catalyst in the ammonia synthesis can be considerably augmented on the replacement of “Sibunit” by catalytic filamentous carbon CFC-III or MgO. The use of γ-Al2O3 or carbon-coated γ-Al2O3 as supports decreases the reaction rate. An introduction of metallic potassium into the K2[Ru(CO)4] catalysts on “Sibunit” and CFC-III accelerates strongly the process of the ammonia synthesis. The highest activity is exhibited by the K2[Ru(CO)4]+K system on “Sibunit” at the metallic potassium to carbon molar ratio of 0.08. On using this catalyst (3.55 g), the steady ammonia concentration in the gas flow at 300 °C and 1 atm amounts to 71.1% of the equilibrium value while at 350 and 400 °C the process of the ammonia synthesis fully reaches the equilibrium. In its efficiency in the ammonia production at 250–300 °C, the K2[Ru(CO)4]+K catalyst on “Sibunit” carbon significantly exceeds the previously developed K2[Ru4(CO)13]+K catalyst on the same support.
Cite:
Yunusov S.M.
, Kalyuzhnaya E.S.
, Moroz B.L.
, Ivanova A.S.
, Reshetenko T.V.
, Avdeeva L.B.
, Likholobov V.A.
, Shur V.B.
New Ammonia Synthesis Catalysts Based on Supported Potassium Carbonyl Ruthenates as Precursors of Catalytically Active Ruthenium Particles and Potassium Promoter
Journal of Molecular Catalysis A: Chemical. 2004. V.219. N1. P.149-153. DOI: 10.1016/j.molcata.2004.04.031 WOS Scopus РИНЦ ANCAN OpenAlex
New Ammonia Synthesis Catalysts Based on Supported Potassium Carbonyl Ruthenates as Precursors of Catalytically Active Ruthenium Particles and Potassium Promoter
Journal of Molecular Catalysis A: Chemical. 2004. V.219. N1. P.149-153. DOI: 10.1016/j.molcata.2004.04.031 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Jan 21, 2004 |
| Accepted: | Apr 30, 2004 |
| Published online: | Jun 7, 2004 |
| Published print: | Sep 1, 2004 |
Identifiers:
| Web of science: | WOS:000222878700018 |
| Scopus: | 2-s2.0-3042793151 |
| Elibrary: | 13455835 |
| Chemical Abstracts: | 2004:561886 |
| Chemical Abstracts (print): | 142:267420 |
| OpenAlex: | W2047001997 |