Intermediates and carbonaceous deposits in the hydrogenolysis of ethane on a Ni-Al/sub 2/O/sub 3/ catalyst

Hydrogenolysis of ethane and hydrogenation of ethylene were performed on a fresh and carburized nickel/alumina (Ni/Al/sub 2/O/sub 3/) catalyst. It was deduced that any type of carbon deposits on Ni/Al/sub 2/O/sub 3/ could retard the hydrogenolysis of ethane (C/sub 2/H/sub 6/) provided they were stable under the reaction conditions, while such carbonaceous deposits did not retard the hydrogenation of ethylene C/sub 2/H/sub 4/. The action of the carbon deposits was quite analogous to that of inert components such as Cu in the copper-nickel (Cu-Ni) alloy in the two reactions. The results suggested that the rate determining step might be C-C bond cleavage of highly dehydrogenated precursor species which subsequently yielded reactive methylene (CH/sub 2/) species with H/sub 2/. 5 figures, 1 table.