Electrochemical Synthesis of Mesoporous Pt–Au Binary Alloys with Tunable Compositions for Enhancement of Electrochemical Performance

Abstract

Mesoporous Pt-Au binary alloys were electrochemically synthesized from lyotropic liquid crystals (LLCs) containing corresponding metal species. Two-dimensional exagonally ordered LLC templates were prepared on conductive substrates from diluted surfactant solutions including water, a nonionic surfactant, ethanol, and metal species by drop-coating. Electrochemical synthesis using such LLC templates enabled the preparation of ordered mesoporous Pt-Au binary alloys without phase segregation. The framework composition in the mesoporous Pt-Au alloy was controlled simply by changing the compositional ratios in the precursor solution. Mesoporous Pt-Au alloys with low Au content exhibited well-ordered 2D hexagonal mesostructures, reflecting those of the original templates. With increasing Au content, however, the mesostructural order gradually decreased, thereby reducing the electrochemically active surface area. Wide-angle X-ray diffraction profiles, X-ray photoelectron spectra, and elemental mapping showed that both Pt and Au were atomically distributed in the frameworks. The electrochemical stability of mesoporous Pt-Au alloys toward methanol oxidation was highly improved relative to that of nonporous Pt and mesoporous Pt films, suggesting that mesoporous Pt-Au alloy films are potentially applicable as electrocatalysts for direct methanol fuel cells. Also, mesoporous Pt-Au alloy electrodes showed a highly sensitive amperometric response for glucose molecules, which will be useful in next-generation enzyme-free glucose sensors.

Substrate-induced assembly of PtAu alloy nanostructures at choline functionalized monolayer interface for nitrite sensing

“…They usually demonstrate higher catalytic activity, faster response rate, and better resistance to deactivation for various chemical processes [3,4], which are ascribed to electronic (ligand) effects and/or geometric effects caused by the surface atomic environment of distinct metal atoms [5][6][7]. In recent years, a variety of intriguing strategies have been designed to prepare alloy nanoparticles, such as laser ablation [8], cathodic corrosion [9], chemical reduction [10,11], salt impregnation [12], colloidal synthesis [13], and dendrimer templating method [14].…”

“…In recent years, a variety of intriguing strategies have been designed to prepare alloy nanoparticles, such as laser ablation [8], cathodic corrosion [9], chemical reduction [10,11], salt impregnation [12], colloidal synthesis [13], and dendrimer templating method [14]. These methods are helpful for the study of alloy nanomaterials, while relatively time-consuming operations, complicated experimental conditions, or surface contamination arising from surfactant are commonly involved, which hinder their further applications [3,5].…”

High-performance polypyrrole functionalized PtPd electrocatalysts based on PtPd/PPy/PtPd three-layered nanotube arrays for the electrooxidation of small organic molecules

“…For example, the electrocatalytic reaction is kinetically limited, the low CO poisoning tolerance causes severe durability of catalyst, and the scale of Pt catalysts leads to high cost. [6][7][8][9][10] To address these issues, many recent efforts have been devoted to synthesizing Pt-M bimetallic electrocatalysts (where M ¼ Pd, Co, Ni, Fe, Au, Cu, and so on). [11][12][13][14][15][16] The bimetallic Pt-based electrocatalysts have unusual electronic structures and arrangements of surface atoms in the near-surface region, and accordingly exhibit improved electrocatalytic activity and cycle stability compared with the monometallic Pt.…”

A mixed-solvent route to unique PtAuCu ternary nanotubes templated from Cu nanowires as efficient dual electrocatalysts

“…This phenomenon may explain the volcano-type dependence of PtAuCu-AA NTs. What is particularly worth mentioning is that Yamauchi et al [54] reported similar result that the Pt 90 Au 10 binary alloys show best stability.…”