Iron-rhodium cluster catalyst

Iron-platinum carbonyl clusters, characteristics, 8, 415 Iron reagents, in Kumada-Tamao-Corriu reaction, 11, 21 Iron-rhodium clusters, as heterogeneous catalyst precursors,... 

Scheme 1.63 Preparation of an iron-rhodium cluster as a catalyst for hydroformylation.

Platinum-iron on alumina catalysts were characterized by Mbssbauer spectroscopy (Section 4) and their activity tested. Iron in clusters with high Pt Fe ratios, about 5, and fully combined with platinum, was catalytically inert for the CO-H2 synthesis reaction, attributed to a decrease in the electron density of the iron as indicated by the Mbssbauer isomer shift. The direction of electron transfer was opposite to that proposed for alkali-metal promoted iron catalysts. At low Pt Fe ratio, 0.1, ferromagnetic iron as well as Fe " ions and PtFe clusters were produced and dominated the activity/selectivity pattern. Rhodium on silica catalysts produced C2-compounds containing oxygen, specifically acetic acid, acetaldehyde and ethanol, with methane as the other major product. The addition of iron moved the C2-product formation sharply in favour of ethanol and now methanol was also formed. ... 

Besides interstitial carbon atoms, nitride groups have also been used to stabilize the cluster structure of iron-rhodium and iron-iridium hydroformylation catalysts [18]. 

Hydrothermal methods, for molecuarlar precursor transformation to materials, 12, 47 Hydrotris(3,5-diisopropylpyrazolyl)borate-containing acetylide, in iron complex, 6, 108 Hydrotris(3,5-dimethylpyrazolyl)borate groups, in rhodium Cp complexes, 7, 151 Hydrotris(pyrazolyl)borates in cobalt(II) complexes, 7, 16 for cobalt(II) complexes, 7, 16 in rhodium Cp complexes, 7, 151 Hydrovinylation, with transition metal catalysts, 10, 318 Hydroxides, info nickel complexes, 8, 59-60 Hydroxo complexes, with bis-Cp Ti(IV), 4, 586 Hydroxyalkenyl complexes, mononuclear Ru and Os compounds, 6, 404-405 a-Hydroxyalkylstannanes, preparation, 3, 822 y-Hydroxyalkynecarboxylate, isomerization, 10, 98 Hydroxyalkynes, in hexaruthenium carbido clusters, 6, 1015 a-Hydroxyallenes... 

In the effort to modify the catalytic properties of rhodium, Wilson and co-workers prepared Rh/Fe/Si02 and other two-metal-silica combinations (74) methanol yields over a Rh/Fe/Si02 catalyst shown in Table XIV were higher than those over the Rh/MgO, Rh/ZnO, and Rh/LaB6 catalysts prepared from cluster carbonyls, but the selectivity of the latter toward methanol was better than that of bimetallic rhodium-iron catalysts. 

Re2(CO)io]/ as well as cluster carbonyls of iron, ruthenium, osmium, rhodium, and iridium. " Catalysts that are obtained in basic aqueous-methanol solution of metal carbonyls of the type M(CO)6 (M = Cr, Mo, W) and M3(CO)i2 (M = Ru, Os) are active even in the presence of sodium sulfide.Most commonly utilized solvents have been mixtures of water with alcohols, methoxyethanol, pyridine, etc. (mainly in the case of neutral solutions and those containing bases, such as KOH, K2CO3). Catalysts that are active in acidic media include Rh2Cl2(CO)4- -HCl- -NaI (solvent H0Ac-hHCl + H20),<"" [Rh(bipy)2]Cl, " > and... 

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