Low-Temperature Solution-Phase Synthesis of NiAu Alloy Nanoparticles via Butyllithium Reduction: Influences of Synthesis Details and Application As the Precursor to Active Au-NiO/SiO2 Catalysts through Proper Pretreatment

Bimetallic nanoparticles (NPs) have wide applications in electronics, photonics, and catalysis. However, it is particularly challenging to synthesize size-controllable alloy nanoparticles (e.g., NiAu) with bulk immiscible metals as the components. Here we report the synthesis of isolable NiAu alloy nanoparticles with tunable and relatively uniform sizes via a coreduction method employing butyllithium as the reducing agent and trioctylphosphine as the protecting agent. The influences of synthesis conditions (e.g., protecting agent, aging temperature, and the solvent used to wash the product) were investigated, and the synthesis mechanism was preliminarily surveyed. The NiAu alloy nanoparticles obtained were then used as the precursor to prepare an Au-NiO/SiO2 catalyst highly active in low-temperature CO oxidation, and the effects of pretreatment details and catalyst compositions on catalytic activity were studied. Relevant characterization employing XRD, TEM, UV-vis, TG/DTG, and FT-IR was conducted. In addition, the importance of the current synthesis of NiAu alloy NPs and the contribution of the catalyst design were discussed in the context of the literature.