TITLE: Improved Fischer-Tropsch Synthesis Catalysts for Indirect Coal Liquefaction: Final Quarterly Technical Progress Report No. 4 for the Period 1 July to 30 September 1986.

AUTHOR: J. G. McCarty;   R. B. Wilson;   G. T. Tong.

INST.  AUTHOR: SRI International, Menlo Park, CA.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  12 Nov 86,  21p.

NTIS ORDER NO.: DE87005037/INW

ABSTRACT:

We have made significant progress in developing novel catalysts for the Fischer-Tropsch synthesis (FTS). The stoichiometries of the cluster synthesis and surface-confining reactions on an alumina support for aluminum tetra- and aluminum hexa-ruthenium hydridocarbonyl cluster catalysts were determined by gas evolution measurements. Characterization with FTIR and NMR spectroscopy of the cluster intermediates is also consistent with the observed cluster catalyst stoichiometry, Al sub 2 O sub 3 -Al(C sub 2 H sub 5 )-Ru sub 4 H sub 3 (CO) sub 12 and Al sub 2 O sub 3 -Al(C sub 2 H sub 5 )-Ru sub 6 H(CO) sub 18 . Activation of the surface-confined supported cluster complex by heating to 573 K in inert gas or hydrogen is likely to produce a stabilized cluster catalyst due to affinity of aluminum for alumina and the strength of the aluminum-ruthenium bonds relative to ruthenium-ligand bonds. The cluster catalysts were tested for FTS in 2:1 H sub 2 :CO syngas at 523 K and 1 atm. The 0.6 wt % Ru sub 4 catalyst had superior activity and about the same selectivity through C sub 8 hydrocarbons as a commercial alumina-supported 0.5 wt % Ru catalyst. The 1.2 wt % Ru sub 6 catalyst was less active but had similar selectivity. Substantial changes in selectivity of standard-fused iron catalysts were found following treatment to uniformly chemisorb submonolayer quantities of sulfur.  Approximately 40% of a monolayer of sulfur was slowly adsorbed at 473 K on the potassium-promoted fused iron catalyst following reduction and passivation by accumulation of a surface layer of carbon and CO. The passivating layer was removed and the sulfur was locally dispersed by heating to 1000 K in hydrogen. The treated catalyst had a three-fold reduction in methane selectivity-relative to untreated reduced fused iron at 573 K, and the C sub 2 olefin yield approached 100%. 7 refs., 1 fig., 3 tabs. (ERA citation 12:015284)

REPORT  NUMBER: DOE/PC/80016-T2

CONTRACT  NUMBER: AC22-85PC80016