Towards improved iron-based catalysts for direct coal liquefaction
- West Virginia Univ., Morgantown, WV (United States); and others
Iron-based catalysts for direct coal liquefaction (DCL) have several advantages: they are cheap and environmentally benign, and have a reasonable activity in the sulfide form. Work in this area has recently been collected and published. work in our laboratory has focussed on catalysts made with ferric sulfide as a precursor. This material is unstable even at room temperature, and disproportionates to form pyrite (FeS{sub x}; PY) , non-stoichiometric pyrrhotite (FeS{sub x}, x {approx} 1; PH) , and elemental S. The value of x and the relative amounts of PY and PH depend upon the time and temperature of disproportionation. Materials from hydrothermal disproportionation at 200{degrees}C for 1 h have roughly equal amounts of PH and PY (on an iron basis), and these materials appear to make the most active and selective catalysts for DCL. These catalyst precursors and catalyst materials have been characterized by atomic adsorption spectroscopy (AA), Auger electron spectroscopy (AES) and x-ray diffraction (XRD). The characterizations have been correlated to the reactions of Fe during disproportionation and to the performance of the catalysts. Improvements in these catalysts can be made in two ways: by altering the active sites, and by decreasing the particle sizes. In the present work, we present examples of both types. The active sites are altered by using small amounts of a second metal. The particle sizes are reduced by using an aerosol technique for preparation.
- OSTI ID:
- 254841
- Report Number(s):
- CONF-940813--
- Country of Publication:
- United States
- Language:
- English
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