(600ap) Decarboxylation and Further Isomerization of Oleic Acid over Pt- Supported on Small Pore Zeolites and Hydrotalcite Catalysts

The catalytic decarboxylation and further conversions of oleic acid to paraffins, branched and aromatic hydrocarbons over Pt supported on small pore zeolites and hydrotalcite is demonstrated. The influence of support, platinum source, and reaction temperature on the decarboxylation of oleic acid were investigated. An increase of reaction temperature increased the degree of decarboxylation and selectivity to heptadecane.  Pt-SAPO-34 was a very effective catalyst. In addition to a high degree of decarboxylation, Pt-SAPO-34 displayed a high selectivity to heptadecane and dodecylbenzene among the products.  Branched  isomers,  cracked (mostly < C17) paraffins, alkenes such undecene, dodecene and carboxylic acids such nonanoic acid, decanoic acid were observed as side products. The further isomerization of the initially formed linear heptadecane (by decarboxylation of oleic acid) to branched isomers is suppressed in the narrow pores of SAPO-34 due to restricted transition state shape selectivity limitations in the pore system of SAPO-34.  Catalyst acidity, dispersion of Pt and pore diameter of the support  played crucial roles in determining product selectivity.