TITLE: Catalytic Synthesis of Hydrocarbons over Group VIII Metals: A Discussion of the Reaction Mechanism.

AUTHOR: A. T. Bell.

INST.  AUTHOR: California Univ., Berkeley. Lawrence Berkeley Lab.

SPONSOR: California Univ., Berkeley. Dept. of Chemical Engineering.*Department of Energy, Washington, DC.


PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  Sep 80,  46p.


The renewed interest in Fischer-Tropsch synthesis experienced during the past decade has motivated a careful reexamination of the previously proposed mechanisms and brought forward a number of new results. The most significant outcome of these recent investigations has been the suggestion that nonoxygenated, rather than oxygenated, intermediates play a dominant role in the synthesis of hydrocarbons from CO and H sub 2 . Moreover, results obtained from the fields of surface science organometallic chemistry, and catalysis strongly support the hypothesis that hydrocarbon synthesis is initiated by the dissociation of CO and that the carbon atoms thus produced are hydrogenated to form adsorbed methylene and methyl groups. The latter species may be considered as precursors to methane as well as centers for hydrocarbon chain growth, a process which is postulated to begin by the insertion of a methylene group into the metal-carbon bond of a methyl group. The function of this review is to summarize the evidence leading to this view of Fischer-Tropsch synthesis and to illustrate its implications for the synthesis of hydrocarbons. In addition, brief discussions are presented concerning the participation of olefins in secondary reactions, which serve to alter the final distribution of products, and the relationship of the mechanism of hydrocarbon synthesis to that for the synthesis of oxygenated products.  (ERA citation 06:005130)