Effects of Organometallic Complexes on Hydrogenation of Coal Tar Pitch for High Performance Carbon Fiber.

Abstract

The effects of organometallic complexes (Fe3(CO)12, Mo(CO)6, Ru3(CO)12, and Ru(acac)3) on the hydrogenation of coal tar pitch for high performance carbon fiber were investigated, and their activities were compared with those of commercial molybdenum-based supported catalysts. The hydrogenation was carried out with tritium-labelled gaseous hydrogen using a 350ml autoclave. The catalysts derived from the organometallic complexes were found to be more active for the hydrogen transfer from the gas phase to pitch than the molybdenum-based supported catalysts. Especially, the ruthenium complexes were most active for hydrogen transfer, and could effectively catalyze the hydrogenation of not only low molecular weight aromatics but also high molecular weight polycondensed ones in pitch. The results from XPS analyses of the used organometallic complexes suggest that the fine metal particles with a reduced state formed at the initial stage of hydrogenation may be the active form for the activation of molecular hydrogen or pitch molecules.