TITLE: Study of Synthesis Gas Conversion over Metal Oxides. Progress Report, August 1, 1983-July 31, 1984.

AUTHOR: J. G. Ekerdt.

INST.  AUTHOR: Texas Univ. at Austin.

SPONSOR: Department of Energy, Washington, DC.


PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  1984,  12p.


The primary objectives of the research are identification of the reaction intermediates present during CO hydrogenation reactions, determination of the reaction pathways whereby the intermediates are converted into products, identification of the active sites for the various steps in CO hydrogenation and the development of an understanding of the causes for catalytic activity and selectivity. Iron oxide and zirconium dioxide catalysts were used to study the Fischer-Tropsch and isosynthesis processes, respectively. Both involve CO hydrogenation but display very different selectivity and catalytic chemistry. The presence of acyl intermediates and their role, if any, in the Fischer-Tropsch process over iron-based catalysts was studied at one to ten atm total pressure and 225 exp 0 C. The studies involved introducing a scavenger into the CO/H sub 2  feed mixture which would selectively react with acyl species and form a compound which was easily identified. The significance of our experiments and their interpretation is difficult to assess at present. We were unable to correlate the concentration of hydrocarbon or oxygenated synthesis products, chiefly methanol and ethanol, with the concentrations of trialkyl amines. A correlation may have suggested if acyl species are formed during the propagation reaction or if they are formed as precursors to aldehyde and alcohol products. The diethyl amine studies do provide consistent evidence that CO insertion does occur over a heterogeneous surface during Fischer-Tropsch synthesis. The isosynthesis studies have included work at 35 atm and at 1 atm. The high pressure work is examining the branching reaction and the C sub 2 -C sub 4 isosynthesis products. The1 atm studies are examining the C sub 1 surface species which may initiate the reaction as well as participate in the formation of C sub 2 + products and are examining the role of surface sites in CO/H sub 2 reactions over ZrO sub 2 . 20 references, 2 figures. (ERA citation 09:022111)