Catalytic decarbonylation of stearic acid to hydrocarbons over activated carbon-supported nickel

In this study, the deoxygenation of stearic acid over a series of Ni-based catalysts in the absence of hydrogen and solvents was investigated. Ni/Al2O3, Ni/TiO2, Ni/ZrO2, and Ni/AC (activated carbon) were synthesized using the wetness impregnation method, and Ni/AC showed the best activity for deoxygenation. X-ray diffraction, transmission electron microscopy, H2 temperature-programmed reduction, and N2 adsorption–desorption analyses revealed that Ni had an average particle size of about 9.6 nm with good crystallinity, the largest surface area and strong Ni–carrier interactions in Ni/AC. These properties of Ni/AC contributed to its good deoxygenation activity. Ni/AC produced hydrocarbons (71.4% yield) such as heptadecane, heptadecene, aromatics, and cracking paraffins under optimized reaction conditions. Furthermore, it was found that the deoxygenation of stearic acid over Ni/AC in the absence of hydrogen and solvent proceeds mainly via decarbonylation.