TITLE: Moessbauer Spectroscopic and Related Characterization of Fischer-Tropsch Catalysts.

AUTHOR: L. N. Mulay.

INST.  AUTHOR: Pennsylvania State Univ., University Park. Dept. of Materials Science and Engineering.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  Mar 81,  96p.

ABSTRACT:

Medium pore (diameter approximately 6 angstrom) zeolites such as ZSM-5 and Silicalite impregnated with Group VIII metals provide selective catalytic pathways for the conversion of coal-derived synthesis gas to gasoline or olefins. Moessbauer and magnetic studies on these catalysts containing Fe or Fe + Co are reported. The zeolites were impregnated with metal nitrate solutions, reduced and carbided to yield the active catalyst. The freshly impregnated samples showed Fe exp 3+ type spectra. The ZSM-5 (14.7% Fe) and Silicalite (13.6% Fe) samples exposed to H sub 2 (450 exp 0 C) showed approx. 85% reduction to the metallic state. The carbided ZSM-5 (14.7% Fe) revealed a spectrum of Hagg carbide (Fe sub 5 C sub 2), an active component of the catalyst. The used catalysts showed  mixtures of Hagg carbide (Fe sub 5 C sub 2 ) and cementite (Fe sub 3 C).  It is suggested that the selectivity of ZSM-5 (5.6% Fe, 4.5% Co) resulted from Fe-Co alloy formation.

REPORT  NUMBER: DOE/PC/10350-T1

CONTRACT  NUMBER: AC22-79PC10350