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, H-2 temperature-programmed reduction, and N-2 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.