(394e) Catalytic Decarboxylation of Oleic Acid Over Ceria-Zirconia Catalysts

The catalytic deoxygenation of oleic acid was studied over ceria-zirconia mixed metal oxide (CZMMO), Ce_1-xZr_xO₂ (x = 0, 0.25, 0.50, 075 and 1.0), and Fe, Ni, Cu and Rh loaded on the CZMMO catalysts. Experiments were carried out in a continuous flow reactor within the temperature range of 325-425^oC. The gaseous products mainly are CO and CO₂ while the main compositions in liquid products are C₁₇ and C₁₈ hydrocarbons. The difference in the product distribution was insignificant for all types of the catalysts used in this work. Surprisingly, Ce_0.75Zr_0.25O₂ exhibits the highest catalytic activity for the deoxygenation of oleic acid with high selectivity toward C₁₇ hydrocarbons. The catalytic activities of metal supported on Ce_0.75Zr_0.25O₂ catalysts are lower than that of Ce_0.75Zr_0.25O₂. This is due to a product hindrance. A kinetic study of deoxygenation of oleic acid over Ce_0.75Zr_0.25O₂ support was further carried out. First order kinetic was well fitted for the deoxygenation of oleic acid and the estimated activation is ca. 23 kcal mol^-1.