Shape-selective hydrogenation of naphthalene over zeolite-supported Pt and Pd catalysts

Per-hydrogenation of naphthalene produces both cis-decalin (c-DeHN) and trans-decalin (t-DcHN). Huang and Kang reported the rate data shown in Scheme 1 for this reaction catalyzed by Pt/Al{sub 2}O{sub 3}. Isomerization of c-DeHN was treated as irreversible, and it was assumed that dehydrogenation of DeHN could be neglected. We have found it possible to achieve high selectivity for one DeHN isomer by appropriate catalyst selection. For example, PYHY gives 100% naphthalene conversion to decalins with 80% selectivity for c-DeHN. There numerous potential industrial applications for c-DeHN; such as, the production of sebacic acid which can be used in the manufacture of Nylon 6, 10 and softeners. Conversely, catalysts that promote the thermodynamically favored c-DeHN to t-DeHN isomerization can be made to give nearly 96% t-DeHN. This reaction can be used in fuel upgrading applications, to increase the thermal stability of the fuel.