An amorphous Ni–B/TiO₂ catalyst has been synthesized by silver-catalyzed electroless nickel plating. The amorphous structure of Ni–B nanoparticles was characterized by X-ray diffraction (XRD) and selected area electron diffraction (SAED). A transmission electron micrograph (TEM) of the Ni–B/TiO₂ showed particles with size ranging from 30 to 50 nm were homogeneously dispersed over TiO₂ support. High-resolution transmission electron microscopy (HRTEM) indicated that the Ni–B nanoparticles presented a porous and flower-like morphology, which was different from the solid sphere of conventional Ni–B particles prepared by impregnation–reduction method. To investigate the formation process of the porous Ni–B particles, the diffusion of nickel nuclei and the growth of Ni–B particles were characterized. The as-prepared porous Ni–B/TiO₂ catalyst exhibited superior catalytic activities in the hydrogenation reactions to those of catalysts prepared by conventional methods.