Transition metal catalysis and natural gas generation

Xiao (1998) applied ab initio calculations to test the transition metal catalysis hypothesis. The key is to understand the kinetics and mechanisms of catalytic gas generation, promoted by transition metals through the activation of alkanes and the condensation of hydrogen and a-alkenes, as well as weather these reactions can proceed under realistic geological conditions. 

Alkanes are usually stable compounds and that makes the selective transformation into other compounds difficult. Transition metals have commonly been used in the 

That is, the atom of the transitional metal inserts into a C-C bond and a C-H bond to form a reaction intermediate. The metal-carbon (M-C) bond in the reaction intermediate is considerably weaker and will subsequently rupture to yield methyl or H radicals. The methyl radical will combine with a hydrogen radical to form methane. Therefore, the metal insertion becomes the rate-determining step and has to be understood. 

Blomberg et al. (1991) conducted ab initio study of the activation of alkane C-H and C-C bonds by different transition metals. The metals studied are iron, cobalt, nickel. 

Mango and Elrod (1999) measured the carbon isotopic composition of catalytic (using Ni metal compounds) gas generated from crude oil and pure hydrocarbon between 150 and 200°C. The measured 5 C for Cl through C5 was linear with l/n n = carbon number), in accordance with theory and natural observation. This result further supports to the view that catalysis by transition metals may be a source of natural gas. 

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