Composition-dependent electrocatalytic activity of AuPd alloy nanoparticles prepared via simultaneous sputter deposition into an ionic liquid

Abstract

Homogeneously alloyed bimetallic particles of AuPd with an average size of ca. 2 nm were successfully prepared by simultaneous sputter deposition of Au and Pd in an ionic liquid in the absence of any additional stabilizing agents. The chemical composition of the AuPd alloy was tunable depending on the area fraction of Au plates in the Au-Pd binary targets for sputtering. The particles were immobilized on an HOPG surface by heat treatment along with the increase in the average size of particles from ca. 2 nm to ca. 7 nm. Ionic liquid species adsorbed on the as-prepared AuPd nanoparticle films on HOPG caused the prevention of electrocatalytic reactions, but repetition of potential sweep cycling in a basic aqueous solution removed the adsorbed ionic species, resulting in electrocatalytic oxidation of ethanol at the AuPd alloy nanoparticle-immobilized HOPG electrode. The electrocatalytic activity of AuPd nanoalloy particles varied upon changing the fraction of Au and Pd in the particles, and alloy particles having an Au fraction of ca. 0.61 exhibited the maximum activity against ethanol oxidation, being higher than the activity of the pure Pt surface.

A review of plasma–liquid interactions for nanomaterial synthesis

“…In addition to using the chemical processes in the PLIs, the physical sputtering process can also be used to synthesize alloy NPs, such as AuAg [121,244,245] and AuPd [246] by using the experimental setup as shown in Fig. 5.…”

Electrodeposition of palladium from palladium(II) acetylacetonate in an amide-type ionic liquid

“…It is well known that ionic liquids can stabilize and disperse metal nanoparticles, so that various preparation methods have been developed. Electrodeposition of Pd or Pd alloys has been investigated in some ionic liquids [4][5][6], even as their nanoparticles were prepared in the ionic liquids [7][8][9][10]. We have also reported the electrodeposition of Pd from an aprotic ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) containing PdCl 4 2 − and PdBr 4 2 − [11,12].…”

Core–Shell-Structured Low-Platinum Electrocatalysts for Fuel Cell Applications

“…As for PdM (M = Ni, Co, Fe, and Cu) cores, these have also been extensively studied as catalysts for ORRs and organic small molecules [76,114,115,119,127,128,135,298,400,[493][494][495][496][497][498][499]. In these reports, there are many reported similarities between PdM@Pt with PtM@Pt catalysts.…”

“…Bimetallic films can also be prepared by using successive sputtering techniques, and core-shell-structured electrocatalysts can be formed in the case in which one layer of deposited metal is covered by a subsequent layer of deposited metal. Room temperature ionic liquids (RTIL) can also be introduced into sputtering deposition procedures to control metal nanoparticle sizes and morphologies, and this process is called the RTIL/metal sputtering technique [398][399][400]. And by using this technique with the ionic liquid of 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate (HyEMI-BF4), uniform Au@Pt electrocatalysts for ORR can be prepared (Fig.…”