Deoxygenation of palmitic and stearic acid over supported Pd catalysts: Effect of metal dispersion

Catalytic deoxygenation of palmitic and stearic acids mixture was studied over four synthesized Pd catalysts supported on synthetic carbon (Sibunit) in a semibatch reactor and dodecane as a solvent at 260-300 degrees C. The catalysts were prepared by precipitation deposition method using Pd chlorides as metal precursors. All catalysts contained 1 wt.% Pd, however, the metal dispersion was systematically varied. An optimum metal dispersion giving the highest reaction rate was observed. The main liquid phase products were n-heptadecane and n-pentadecane, which were formed in parallel. In addition to the particle size effect the impact of mass transfer was elucidated and a detail discussion on temperature programmed desorption of CO from the fresh and spent samples was provided. (C) 2008 Elsevier B.V. All rights reserved.