Ni-B非晶态合金催化剂用于卤代硝基苯液相加氢制卤代苯胺

 用化学还原法制备了Ni-B非晶态合金催化剂,并将其用于4种卤代硝基苯的液相加氢反应. 采用X射线衍射和透射电子显微镜研究了催化剂的非晶性质. 在373 K下处理2 h后催化剂保持非晶态结构,在773 K下处理2 h后催化剂完全晶化. 讨论了Ni-B非晶态合金催化剂的催化性能与其结构之间的关系,并与其它Ni基催化剂进行了比较. Ni-B非晶态合金催化剂不仅具有较高的催化活性,而且对卤代芳胺的选择性较高,脱卤率小于4%,优于其它Ni基催化剂.

Liquid-Phase Hydrogenation of Halogenated Nitrobenzene to Halogenated Aniline over Ni-B Amorphous Alloy Catalyst

The Ni-B amorphous alloy catalyst prepared by reduction of nickel nitrate with a potassium borohydride aqueous solution was employed in the liquid-phase hydrogenation of halogenated nitrobenzene. When the Ni-B amorphous alloy was treated at 373 K, no significant crystallization was observed, but it crystallized at 773 K. The relationship between the catalytic selectivity and the nature of the active sites was discussed based on XRD and TEM characterizations. The higher activity and better selectivity of the amorphous Ni-B catalyst could be attributed to the high dispersion of the Ni active sites and was closely related to both the structural and electronic effects of the active sites. In comparison with other Ni-based catalysts, the Ni-B amorphous alloy catalyst exhibited higher activity and better selectivity for halogenated aniline. The dehalogenation was less than 4%.