Cobalt additives, ruthenium catalysis

The elTiciency of cobalt and ruthenium catalysis is not very sensitive to the presence of promoters )21]. With cobalt, the addition of thorium and alkali promoters increases wax production and supports were incorporated to increase the active metal surface area. On the other hand, promoters and supports are essentia) for iron catalysts. 

The shapc-selective catalysis by metal carbonyls deposited in Y zeolites has also been studied by Ballivet-Tkalchenko and Tkaichenko [47. 1351-Iron, cobalt and ruthenium carbonyls in the supercages of acidic and neutral Y zeolites were examined. The product distributirm i limited to the range Ci C9. Fc3(CO)i3 on Na Y zeolite is an active catalyst, whereas Fe3(CO)i2- HY is inactive. However, the addition of the acidic HY zeolite to the Fc3(CO)ii-Y... 

The addition of increasing amounts of iodine promoters accelerates the hydrocarbonylation of methanol, but at the same time detioriates the hydrogenation ability of the cobalt catalysis. To obtain a high ethanol selectivity under these conditions, catalysts active for hydrogenation in the presence of iodine have to be added. Ruthenium compounds have been proved to be most suitable, as was mentioned earlier. Althou no detailed studies on the ruthenium intermediates involved are available, it is well known that aliphatic aldehydes... 

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