Deoxygenation of Fatty Acid Over Three-Dimensionally Ordered Mesoporous Carbon Supported Palladium Catalysts

Abstract

Two ordered mesoporous carbons (OMCs) possessing three-dimensionally (3-D) well-ordered mesoporosity with different framework configurations were prepared via a hard template route. The OMCs were treated with different surface-oxidation methods for the preparation of OMC supported highly dispersed Pd catalysts (Pd/OMC). Among the different surface oxidation conditions, the 3-D ordered mesoporous structure of CMK-9 is preserved under a mild surface-oxidation condition by an ammonium persulfate solution at 30 °C for 2 h. The Pd/OMCs were introduced as catalysts for the catalytic deoxygenation of a fatty acid without hydrogen or different amounts of hydrogen. The catalytic performance of the deoxygenation of a fatty acid (stearic acid) was investigated in a batch reactor without hydrogen and a continuous fixed-bed reactor with different amounts of hydrogen (H2/stearic acid = 0–3 molar ratios). The Pd/OMC catalysts were found to be less prone to deactivation than a commercially available activated carbon supported Pd catalyst (Pd/AC). This was attributed to the well-ordered 3-D mesoporosity in the OMC supports, which facilitated the facile diffusion of the liquid reactant and product with a long carbon chain length in the catalyst during the deoxygenation reaction, leading to less Pd metal sintering during the deoxygenation reaction as compared to that with Pd/AC catalyst.