Ultrasound-assisted preparation of a novel Ni-B amorphous catalyst in uniform nanoparticles for p-chloronitrobenzene hydrogenation

摘要

Uniform Ni-B amorphous alloy nanoparticles were prepared by ultrasound-assisted reduction of Ni(NH3)_6~(2+) with BH_4~-in aqueous solution and the particle size was controlled by adjusting the ultrasound power.During liquid-phase p-chloronitrobenzene hydrogenation,the as-prepared Ni-B catalyst exhibited much higher activity and better p-chloroaniline selectivity than the regular Ni-B obtained via direct reduction of Ni~(2+) with BH4.The higher activity could be attributed to both higher dispersion of Ni active sites and higher intrinsic activity.The higher selectivity could be attributed to both uniform Ni-B particles with larger size and Ni active sites with higher electron density.