Carbon alkali metals

The oxygen bases, alkali metal carbonates, alkali metal hydroxides and alkoxides are used to a large extent. The solvents are alcohols, ether, THF, dioxane, glycol or glycol ethers (for higher temperatures), DMSO, HMPA or crown ethers. The latter three increase basicity by generating naked anions, because the cations are strongly solvated. 

The reactions of carbon dioxide and water with carbonaceous species are well known reactions and have been employed in various chemical processes to control or remove unwanted carbonaceous material. The most important application is found in the gasification of coal, forming a mixture of hydrogen and carbon monoxide (syngas), which is also used in important industrial processes such as methanol synthesis and in the production of hydrocarbons (Fischer-Tropsch synthesis). In these reactions, alkali metal catalysts and promoters have been used extensively for their ability to activate water and carbon dioxide species, thus speeding up their reaction with carbon. Alkali metals are therefore a clear candidate for this study. A number of mechanisms have been suggested... 

Sodium is also able to form sucb compounds with the approximate formula C64Na. The compounds with the highest alkali content (i.e. CgMe) decompose under vacuum at elevated temperatures to yield alkali metal vapour and compounds with a higher carbon/alkali metal ratio according to Eq. (11). 

As already highlighted in the partial list of Scheme 20, various groups of compounds may act as precursors alkali metals alkali metal hydrides, oxides, hydroxides, alkoxides, halides, carbonates alkali metal salts of organic acids alkyl aluminums alkali aluminum hydrides and their alkoxides quaternary ammonium salts guanidium salts of lactams, etc. 

Ruthenirrm, promoted by alkali metals and barium and then supported on carbon, has provided a significant increase in activity compared with iron catalysts. The high cost of rathenium when compared with iron must have led to it being used with the cheap support material. In retrospect, the complex interaction between carbon, alkali metal and barium with the active mthenium led to the development of a successful catalyst. A magnesimn oxide support has now been claimed to give a longer life than caibon. ... 

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