Decarboxylation of Fatty Acid over Pd Supported Mesoporous Carbon

Abstract

Decarboxylation of vegetable oils into long-chain hydrocarbons is one of the important routes for producing a sustainable biofuel. The resultant products can be directly applied in the current diesel engine systems. This is a great advantage in comparison with fatty acid methyl ester, so called biodiesel, which poses some critical problems such as high viscosity and cloud point, and corrosive properties. Recently, this decarboxylation process has been demonstrated using Pd on microporous activated carbon(Pd/C) and the activity was verified. However, this catalyst is deactivated rapidly in fixed bed reactor. In the present work, we demonstrated the effect of mesoporous carbon support on the catalytic behaviors in decarboxylation of oleic acid. As the supporting material, we used an ordered mesoporous carbon material designated by CMK-8 whose structure belonged to the cubic Ia3d. Pd/C and Pd/CMK-8 showed similar initial activity regardless of metal dispersion. Although the presence of mesopores slowed down the deactivation in comparison with Pd/C, deactivation was a still serious problem for practical application. By characterization of fresh and used catalyst, it was concluded that coke generation is the main reason of deactivation.