Selective hydrogenation of oleic acid over Flower-like Ni-Fe/SiO2-ZrO2 catalyst to produce fatty alcohol: Effect of SiO2

To solve the problem of harsh reaction conditions in lipid hydrogenation into fatty alcohol over Cu based bimetallic catalysts, the cheap Ni-base catalyst with high activity was synthesized. By using the hydrothermal method, the flower-like SiO2-ZrO2 support was prepared. The Ni-Fe/SiO2-ZrO2 catalyst was further prepared by the impregnation method and utilized in the fatty acid hydrogenation to produce fatty alcohol. Under the re-action conditions (240 degrees C, initial H2 pressure: 2 MPa and reaction time: 3 h), the Ni-Fe/0.13SiO2-ZrO2 catalyst attained 96.0% conversion and 86.4% fatty alcohol yield, much higher than that of Ni-Fe/ZrO2 without SiO2 (conversion 86.1% and fatty alcohol yield 61.9%). The high catalytic activity of Ni-Fe/0.13SiO2-ZrO2 was ascribed to the increase of surface area, reduction of NiO grain size, and formation of flower-like morphology. The high selectivity to fatty alcohol over Ni-Fe/0.13SiO2-ZrO2 was related to the increase of Lewis acidity (extra active sites) and the decrease of oxygen vacancy which weakened the adsorption of aldehyde (enol) on the catalyst and thus facilitated the formation of fatty alcohol.