Fullerene Black: Relationship between Catalytic Activity in n-alkanes Dehydrocyclization and Reactivity in Oxidation, Bromination and Hydrogenolysis

Abstract

<p>The reactivity of fullerene black in oxidation (by air oxygen or ions MnO₄^– or Cr₂O₇^2– in solution), bromination (by Br₂ or (C₄H₉)₄NBr₃) and hydrogenolysis (without hydrogenation catalyst) are studied. The dehydrocyclization of <em>n</em>-alkanes over fullerene black is realized via the monofunctional mechanism, <em>i.e. </em>the dehydrogenation and cyclization stages proceed on the same catalytic center. The addition of alumina to the catalyst transforms dehydrocyclization mechanism to bifunctional one, when fullerene black acts as dehydrogenation agent. Reactivity studies and ESR spectroscopy data for initial and annealed fullerene black show the presence in fullerene black structure of both non-conjugated multiple and dangling bonds. Nonconjugated bonds determine catalytic activity and reactivity of fullerene black. They are localized in amorphous part of fullerene black. Technological aspects of fullerene black as alkanes dehydrocyclization catalyst are discussed.</p>