Catalytic upgrading of fatty acid to fatty alcohol over cobalt silica catalysts

This article reports the application of Co/SiO₂ catalysts for the hydrogenation of stearic acid to selectively produce stearyl alcohol. Samples of Co/SiO₂ with cobalt loadings of 4–10 wt% were prepared using a wetness impregnation method. The effect of cobalt loading on catalyst properties was investigated with X-ray diffraction, N₂ adsorption–desorption, H₂ temperature programmed reduction, and H₂ chemisorption. The influence of cobalt loading on activity and stearyl alcohol selectivity was examined by performing reactions in a batch reactor at 300 °C and 5 MPa. The results indicated that the cobalt loading influenced activity according to the number of metallic sites available. The Co/SiO₂ was shown to convert stearic acid to stearyl alcohol with high selectivity (>90%), with octadecanal, octadecane, and heptadecane as byproducts. Selectivity to stearyl alcohol was maintained above 90% for cobalt loadings of 4–8 wt%.