EFFECTS OF IRON-OXYGEN PRECURSOR PHASE ON CARBON-CARBON BOND SCISSIONIN NAPHTHYLBIBENZYLMETHANE

Eleven iron-oxygen compounds prepared using standard laboratory synthe ses were tested as precursors for carbon-carbon bond scission catalyst s with the coal model compound naphthylbibenzylmethane in the presence of elemental sulfur and a hydrogen-donating solvent. The structure of the iron-oxygen catalyst precursor was found to be the most significa nt factor determining the reactivity of the catalyst produced. The rea ctivity of the iron-oxygen compounds showed little : apparent correlat ion with surface area, iron content, or water content. The iron-contai ning single-phase materials with the best catalytic activity at 400 de grees C were determined to be ferric oxyhydroxysulfate (Fe8O8(OH)(8)SO 4), six-line ferrihydrite, goethite ((alpha-FeOOH), and akaganeite (be ta-FeOOH). The worst iron-oxygen compounds were found to be wustite (F eO), two-line ferrihydrite, magnetite (Fe3O4), and maghemite (gamma-Fe 2O3). The general order of reactivity of the iron-oxygen compounds tow ard carbon-carbon bond scission was found to be proto-oxyhydroxides > oxyhydroxides > oxides. All of the iron-oxygen compounds tested were a t least as active as metallic iron (alpha-Fe). All of the active I cat alyst precursors produced similar distributions of organic reaction pr oducts from the model compound. The best catalyst precursor tested was ferric oxyhydroxysulfate, which formed a catalyst which selectively c leaved carbon-carbon bonds at the a-naphthyl-methylene (''a'') and the beta-naphthylmethylene (''b'') positions with a model compound consum ption of greater than 90% under the test; conditions. The ferric oxyhy droxysulfate was found to contain a relatively large amount of water a nd small amount of iron, 18% and 43%, respectively, by weight.