Résultat de la recherche
Ruthenium nanoparticles intercalated in hectorite: a reusable hydrogenation catalyst for benzene and toluene
The cationic organometallic aqua complexes formed by hydrolysis of [(C6H6)RuCl2]2 in water, mainly [(C6H6)Ru(H2O)3]2+, intercalate into sodium hectorite by ion exchange, replacing the sodium cations between the anionic silicate layers. The yellow hectorite thus obtained reacts in ethanol with mol. hydrogen (50 bar, 100°) with decompn. of the organometallic aqua complexes to give a black material, in which ruthenium(0) nanoparticles (9-18 nm) are intercalated between the anionic silicate layers, the charges of which being balanced by hydronium cations. The black ruthenium-modified hectorite efficiently catalyzes the hydrogenation of benzene and toluene in ethanol (50 bar H2, 50°), the turnover frequencies attaining 7000 catalytic cycles per h. [on SciFinder(R)]
Supramolecular cluster catalysis : facts and problems
By checking the chemistry underlying the concept of "supramolecular cluster catalysis" we identified two major errors in our publications related to this topic, which are essentially due to contamination problems. (1) The conversion of the "closed" cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) into the "open" cluster cation [H2Ru3(C6H6)(C6Me6)2 (O)(OH)]+ (2), which we had ascribed to a reaction with water in the presence of ethylbenzene is simply an oxidation reaction which occurs in the presence of air. (2) The higher catalytic activity observed with ethylbenzene, which we had erroneously attributed to the "open" cluster cation [H2Ru3(C6H6)(C6Me6)2(O)(OH)]+ (2), was due to the formation of RuO2• nH2O, caused by a hydroperoxide contamination present in ethylbenzene.
Ruthenium Nanoparticles Intercalated in Hectorite: A Reusable Hydrogenation Catalyst for Benzene and Toluene
The cationic organometallic aqua complexes formed by hydrolysis of [(C6H6)RuCl2]2 in water, mainly [(C6H6)Ru(H2O)3]2+, intercalate into sodium hectorite by ion exchange, replacing the sodium cations between the anionic silicate layers. The yellow hectorite thus obtained reacts in ethanol with molecular hydrogen (50 bar, 100°C) with decomposition of the organometallic aqua complexes to give a black material, in which ruthenium(0) nanoparticles (9–18 nm) are intercalated between the anionic silicate layers, the charges of which being balanced by hydronium cations. The black ruthenium-modified hectorite efficiently catalyses the hydrogenation of benzene and toluene in ethanol (50 bar H2, 50°C), the turnover frequencies attaining 7000 catalytic cycles per hour.
Supramolecular cluster catalysis: facts and problems
By checking the chem. underlying the concept of supramol. cluster catalysis the authors identified two major errors in their publications related to this topic, which are essentially due to contamination problems. (1) The conversion of the closed cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) into the open cluster cation [H2Ru3(C6H6)(C6Me6)2(O)(OH)]+ (2), which the authors had ascribed to a reaction with H2O in the presence of ethylbenzene is simply an oxidn. reaction which occurs in the presence of air. (2) The higher catalytic activity obsd. with ethylbenzene, which the authors had erroneously attributed to the open cluster cation 2, was due to the formation of RuO2·nH2O, caused by a hydroperoxide contamination present in ethylbenzene. [on SciFinder(R)]