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

Abstract

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/SiO 2 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.

Catalysis by gold: New insights into the support effect

“…The structure made of Au-supported MOx (M = Ni [86][87][88][89], Co [90], etc.) could greatly improve the overall catalytic activity of the Au Reprinted from Refs.…”

Development of novel supported gold catalysts: A materials perspective

“…Our group synthesized NiAu nanoparticles via a co-reduction method employing butyllithium as the reducing agent and trioctylphosphine as the protecting agent [88,90]. These nanoparticles were loaded onto an amorphous SiO 2 support to obtain NiAu/SiO 2 .…”

Growth and characterization of Au, Ni and Au–Ni nanoclusters on 6H-SiC(0001) carbon nanomesh

“…Ni has long been recognized as a unique catalyst in steamand CO 2 reforming [13,14]. However, there are many fewer studies dealing with the catalytic applications of Au-Ni catalysts [15,16]. One of the primary reasons lies in the fact that the bulk binary phase diagram of Au-Ni has a large miscibility gap and thus alloy formation becomes difficult at temperatures below 800°C [17,18].…”