Abstract: Lanthanum-promoted Ni-Mo-B amorphous catalysts were prepared by chemical reduction of the corresponding metal salts with sodium borohydride aqueous solution. Scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma atomic emission spectrometry (ICP-AES), and X-ray photoelectron spectroscopy (XPS) were used to characterize the resulting materials. Phenol was used as model compound to test the hydrodeoxygenation (HDO) activity of the La-Ni-Mo-B amorphous catalysts. Adding lanthanum could decrease the particle size, increase the content of Ni⁰ and promote the reduction of Mo⁶⁺ to Mo⁴⁺ . But excess lanthanum would cover some of the Ni⁰, and Mo⁴⁺ active sites. The high hydrogenation activity was attributed to the amorphous structure of the catalyst and the high content of Ni⁰ and the high degree of deoxygenation was attributed to the high content of MoO₂. The HDO reation of phenol on the La-Ni-Mo-B amorphous catalyst proceeded with a hydrogenation-dehydration route, thus decreasing the aromatic content of the HDO products. Both the conversion and the total deoxygenation degree were up to 99.0%. The deactivation of the La-Ni-Mo-B amorphous catalysts during the HDO reation of phenol at high temperature was mainly caused by the crystallization of the amorphous structure.

Key words: Amorphous catalyst, La-Ni-Mo-B, Hydrodeoxygenation, Phenol, Bio-oil