Liquid phase hydrogenation of 2-ethylanthraquinone over La-doped Ni-B amorphous alloy catalysts

A series of La-doped Ni-B amorphous alloy catalysts were prepared by a KBH4 reduction method. Ni powders were prepared by hydrazine reduction. These samples were characterized by inductively coupled plasma (ICP), BET, XRD, X-ray photoelectron spectroscopy (XPS), H-2-chemisorption, H-2-TPD, etc., and studied in the hydrogenation of 2-ethylanthraquinone (EAQ). The Ni-B amorphous alloy catalysts showed higher specific surface area, higher extents of H-2-chemisorption and higher H-2-TPD areas than Ni powders. In Ni-B amorphous alloys, with the addition of La, the extents of H-2-chemisorption and H-2-TPD areas first increased markedly and then decreased, with the maximum appeared at the atomic ratio of La to Ni of 0.034. The hydrogenation activity also showed the same trend. The effects of La were attributed to its dispersion of Ni particles, resulting in the formation of more surface Ni centers. However, much higher La contents may result the coverage of surface Ni centers. After heat treatment at higher temperatures, the amorphous structure of Ni-B was destroyed. (C) 2003 Elsevier B.V. All rights reserved.