Preparation and Electrochemical Behavior of PtRu(111) Alloy Single‐Crystal Surfaces

Abstract

The electrochemical behavior of a PtRu(111) single crystal with 1:1 bulk atomic ratio is investigated for the first time by means of cyclic voltammetry and scanning tunneling microscopy (STM). The electrode surfaces are enriched with either Ru or Pt, depending on the cooling conditions after inductive heating. Analysis of the surfaces by STM shows a typical topography with smooth terraces separated by monoatomic high steps. The voltammetric characterization of PtRu(111) in acid media clearly reveals an altered electrochemical behavior of the Pt and Ru surfaces compared to Pt(111) and Ru(0001), respectively. Systematic changes are observed for hydrogen adsorption and underpotential deposition of copper as test reactions. Based on theoretical calculations in the literature, it is experimentally verified that the Pt-rich and the Ru-rich surfaces of the PtRu(111) single-crystal alloy bind adsorbates such as hydrogen significantly weaker and stronger than the pure single-crystal electrode surfaces. Such changes in surface reactivity can be crucial for electrocatalytic reactions.

Electrocapillary coupling coefficients for hydrogen electrosorption on palladium

“…This peak corresponds to a similar feature in the CV of the planar Pd surface. In view of literature results on Pd (111) surfaces [24,36] the aforementioned peak can be attributed to H UPD. Figure 3c) displays charge transfer, δQ, versus E. As above, the graph is closed, supporting that the charge can be recovered.…”

Plasmon-Driven Electrochemical Methanol Oxidation on Gold Nanohole Electrodes

“…The strong coupling of light with charge carriers in plasmonic nanostructures has been lately considered ideally suited to accelerate sluggish and complex multielectron electrochemical reactions. − This is due to the generation of energetic charge carriers, hot electrons, and holes, through the localized surface plasmon resonance (LSPR) effects occurring in noble-metal nanostructures. The integration of LSPR structures onto the electrochemical interfaces has thus become an essential part of improving the electrocatalytic redox processes. − In spite of its large potential for boosting catalytic transformations, current advancement in plasmon-enhanced electrocatalysis toward direct methanol oxidation is still under investigation. ,− In this context, it has been demonstrated that bimetallic AgPt hollow nanoparticles with an ultrathin Pt shell of less than 2 nm enhanced the electrocatalytic activity toward methanol oxidation in basic media and the CO poisoning tolerance . Light irradiation at 600 mW/cm 2 resulted in a current density of 18.8 mA/cm 2 .…”

Bimetallic alloys in action: dynamic atomistic motifs for electrochemistry and catalysis

“…Indeed, cyclic voltammetric measurements lead to the conclusion that the surface segregation in both cases is complete so that the surface layer is pure Pt in the former case and pure Ru in the latter. 51 In the case of the Pt-enriched surface, the base voltammogram in 0.1 M H 2 SO 4 (see Fig. 1a) strongly resembles the characteristic base voltammogram for Pt(111) in the same electrolytic solution, with the cation (e.g.…”

“…Thus surface heating followed by cooling under an inert or reductive atmosphere results in the segregation of the less oxophilic Pt to the surface. [49][50][51] Similarly, surface heating followed by cooling under an oxidative (i.e. oxygen-containing) atmosphere draws Ru to the surface.…”