EFFECTS OF IRON CARBONYL-BASED CATALYST PRECURSORS ON THE REACTION OF4-(NAPHTHYLMETHYL)BIBENZYL

The reaction pathways and kinetics of 4-(naphthylmethyl)bibenzyl (NBBM ) were studied in an effort to resolve certain fundamentals underlying catalysis of coal liquefaction by Fe-based catalysts. Reaction of NBB M under a hydrogen atmosphere was performed for a series of iron carbo nyl-based catalyst precursors: Fe(CO)(4)PPh(3), Fe(CO)(3)(PPh(3))(2), and Fe(CO)(2)(PPh(3))(2)CS2. The precursors' activities for the disapp earance of NBBM were Fe(CO)(4)PPh(3) > Fe(CO)(2)(PPh(3))(2)CS2 > Fe(CO )(3)(PPh(3))(2). All precursors gave significantly higher rates than t hat for thermal reaction at 400 degrees C. Thermolysis of NBBM was sel ective for cleavage at the bibenzyl bond, whereas the catalyst precurs ors were selective for cleavage at the naphthyl moiety. Hydrogenation activity was also observed for each of the three catalyst precursors. Possible catalytic reaction mechanisms are considered.