Novel monolithic catalysts for the hydrotreating of oleic acid

Abstract

Alumina-supported palladium and molybdenum carbide monolithic catalysts were tested in the hydrodeoxygenation of oleic acid. Anodized aluminum monoliths were used as the substrate of the structured catalysts. The Pd catalyst was synthetized by wet impregnation, and the Mo₂C sample was prepared in situ using the temperature-programmed carburization methodology. The monolithic catalysts were characterized by X-ray diffraction, N₂ sorption analysis, CO chemisorption and scanning electron microscopy. The catalytic tests were carried out in a continuous tubular reactor at temperatures between 553 and 633 K, with a hydrogen pressure of 30 atm. Both catalysts showed to be active, reaching a conversion of oleic acid higher than 92% at 633 K. The deoxygenation reactions using the Mo₂C catalyst were suppressed, favoring the saturation of carbon-carbon double bonds and the stearic acid formation. On the other hand, oleic acid hydrodeoxygenation was promoted when using the palladium-based catalyst, forming undecane and tridecane alkanes.