Room‐Temperature Morphology‐Controlled Synthesis of Nickel and Catalytic Properties of Corresponding Ru/Ni Catalysts

Abstract Differently shaped nickel crystals were obtained at ambient temperature via simple liquid chemical reduction by adding different surfactants (such as polyvinylpyrrolidone (PVP) or cetyltrimethylammonium bromide (CTAB)), with hydrazine hydrate as reducing agent and ethanol as solvent. Nickel nanoparticles (NPs), thorny nickel nanowires or rose‐like nickel crystals were obtained in the synthesis process without any surfactant, with PVP or with CTAB, respectively. The corresponding ruthenium‐on‐Ni crystal supported catalysts (Ru/Ni) were synthesized through galvanic replacement. Their catalytic behavior was tested in the model reaction of the hydrogenation of benzene. The order of their catalytic activity was Ru/thorny Ni nanowire > Ru/rose‐like Ni > Ru/Ni NPs due to different shapes and structures of Ru/Ni. The Ru/thorny Ni nanowires catalyst also exhibited outstanding stability for benzene hydrogenation to cyclohexane. The as‐obtained Ni and Ru/Ni samples were characterized by X‐ray diffraction (XRD), scanning electronic microscopy (SEM), SEM energy dispersive X‐ray spectroscopy (SEM‐EDS), high‐sensitivity low‐energy ion scattering spectroscopy (HS‐LEIS), X‐ray photoelectron spectroscopy (XPS), SEM‐EDS elemental mapping, transmission electron micro‐scope (TEM), and high resolution TEM (HRTEM), to reveal their morphologies, structures and element distribution and further illustrate the intrinsic reasons for their different performance in catalyzing benzene hydrogenation.