Effects of Fe catalysts and solvent on the hydrogenolysis of 9-benzylphenanthrene under hydrogen at 450°C were investigated.
Both in 1-methylnaphthalene and in tetralin, the 9-benzylphenanthrene conversion decreased in the order: α-Fe>Fe1-xS>Fe2O3. The 9-benzylphenanthrene conversion was higher in tetralin than in 1-methylnaphthalene with any of the above Fe catalysts, and a good linear correlation was obtained between the naphthalene yield and the 9-benzylphenanthrene conversion. These facts support that α-Fe and Fe1-xS promote the bimolecular hydrogen transfer not only from gaseous hydrogen but from tetralin to 9-benzylphenanthrene.
In the presence of α-Fe, adducts of a benzyl radical to 1-methylnaphthalene and tetralin were obtained, suggesting that benzyl radicals can be partly stabilized on the surface of α-Fe.