Abstract: A series of chitosan-mediated expanded graphite-supported amorphous Ni-B alloy catalysts were successfully prepared by a silver-catalyzed electroless plating method in an aqueous solution. The effects of chitosan on the structure, composition, surface texture, and dispersion of Ni-B particles on expanded graphite were characterized by X-ray powder diffraction, inductively coupled plasma analysis, transmission electron microscopy, selected area electron diffraction, and scanning electron microscopy. The characterization results show that the amorphous structure of Ni-B particles is not influenced by chitosan. The activity of as-prepared catalysts was tested by the hydrogenation of sulfolene to sulfolane and the selective hydrogenation of p-chloronitrobenzene to p-chloroaniline. In comparison with the catalyst without chitosan, the presence of a proper amount of chitosan in the catalyst leads to homogeneous dispersion of Ni-B particles, small size of Ni-B particles, and high catalytic activity.

Key words: chitosan, nickel-boron amorphous alloy, sulfolene, p-chloronitrobenzene, catalytic hydrogenation