Catalytic Properties of Fullerene Materials

Abstract

Fullerenes were found to catalyze coupling and transalkylation reactions of mesitylene, engage in transfer hydrogenations with dihydroaromatics, and cleave strong bonds such as those in diarylmethanes. In all of these reactions, fullerenes show a marked ability to accept and to transfer hydrogen atoms. The key structural feature that endows fullerenes with many of its characteristics is the presence of a pentagon surrounded by hexagons. We suspected that fullerene soot, unlike graphitic carbon, contained pentagons in a hexagonal lattice, and that these sites imparted the soot with the desired chemical attributes of strong electrophilic nature and an ability to stabilize radicals. In subsequent studies, we have shown fullerene soot to be very effective in catalyzing various H-transfer reactions, including the conversion of methane into higher hydrocarbons. When compared with other carbons, such as activated carbons and acetylene black, the fullerene soot is much more reactive for oligomerization and hydrodealkylation of alkylbenzenes. Because this activity remains, even in chemically extracted and partially oxidized soot, the observed catalysis is not a result of residual soluble fullerenes.