Structure and dispersion of pyrrhotite catalysts derived from binary ferrihydrites

Conference · Fri Dec 01 00:00:00 EST 1995

OSTI ID:126511

Zhao, Jianmin; Feng, Zhen; Huggins, F E ^[1]

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1. Univ. of Kentucky, Lexington, KY (United States); and others

Previously, we have shown that impurity anions chemisorbed at the surface of binary ferrihydrites can effectively inhibit particle agglomeration at elevated temperatures in air. Under direct coal liquefaction conditions (DCL) in the presence of sulfur, the binary ferrihydrite phase converts to pyrrhotite (Fe{sub 1-x}S). Transmission electron micrographs show that the pyrrhotite phase derived from binary ferrihydrites under DCL conditions is much better dispersed (average particle diameter {approximately}200 {Angstrom}) than the pyrrhotite derived from pure ferrihydrite (average diameter of {approximately}1000 {Angstrom}). In addition, Mossbauer spectroscopy shows that the pyrrhotite phases from binary ferrihydrites contain more Fe vacancies than those derived from pure ferrihydrites; that is, a larger x value in Fe{sub 1-x}S. These findings explain the improved coal liquefaction activity obtained from binary ferrihydrites.

• OSTI ID: 126511
• Report Number(s): CONF-950402-; TRN: 95:006086-0495
• Resource Relation: Conference: 209. American Chemical Society (ACS) national meeting, Anaheim, CA (United States), 2-6 Apr 1995; Other Information: PBD: 1995; Related Information: Is Part Of 209th ACS national meeting; PB: 2088 p.
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL LIQUEFACTION
CATALYSTS
IRON COMPOUNDS
CATALYTIC EFFECTS
CHEMICAL BONDS
CLEAVAGE
PARTICLE SIZE
PRECURSOR
PYRRHOTITE
SPECTROSCOPY
AGGLOMERATION