The effect of specific chloride adsorption on the electrochemical behavior of ultrathin Pd films deposited on Pt() in acid solution

Arenz, Matthias; Stamenković, Vojislav R.; Schmidt, Thomas J.; Wandelt, K.; Ross, Philip N.; Marković, Nenad M.

doi:10.1016/s0039-6028(02)02456-1

Cited by 79 publications

(82 citation statements)

References 39 publications

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“…From an fundamental point of view, the observed activity inhibition in phosphoric acid is to some degree similar to the strong inhibiting effect of chloride contaminations [17,[53][54][55]. Thus one may consider contaminations being responsible for our observations.…”

Section: Methodssupporting

confidence: 61%

On the oxygen reduction reaction in phosphoric acid electrolyte: Evidence of significantly increased inhibition at steady state conditions

Deng

Wiberg

Zana

et al. 2016

Electrochimica Acta

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In the presented work, we investigate the oxygen reduction reaction (ORR) in half-cell measurements employing different electrolytes. The aim is to compare the ORR inhibition due to anion adsorption at transient as well as steady state conditions. It is found that the ORR inhibition at the platinum -phosphoric acid electrolyte interface is a relative slow, time dependent process. The major inhibition is not observed in transient polarization curves but only under steady state 2 conditions. This observation is in contrast to the typical ORR inhibition due to anion adsorption as observed for example in sulfuric acid electrolyte. In sulfuric acid the inhibition is fast and then stays more or less constant in time. As a consequence of our findings, common transient measurements of the ORR activity might not be sufficient to investigate suitable mitigation strategies for the ORR inhibition in phosphoric acid electrolyte. Such strategies need to take steady state conditions into account.In order to explain the slow ORR inhibition in phosphoric acid electrolyte, two possible explanations are discussed. Either the adsorption of phosphate is a slow, complex process, where a fast adsorption step is followed by a consecutive filling of the surface, or a mass transfer barrier develops at the polarized phosphoric acid -electrode interface. The latter might be the viscoelectric effect that is known from colloidal science.

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Section: Methodssupporting

confidence: 61%

On the oxygen reduction reaction in phosphoric acid electrolyte: Evidence of significantly increased inhibition at steady state conditions

Deng

Wiberg

Zana

et al. 2016

Electrochimica Acta

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“…Finally, the best PdCoNi electrocatalyst shows a higher surface activity in the ORR at 0.9 V vs. RHE with respect to the Pt-based reference (388 mA cm Pd -2 vs. 153 mA cm Pt Indeed, it is well-known that the electrochemical behavior of platinum-group metal (PGM) surfaces is strongly affected by anion adsorption. [13][14][15][16] In particular, chloride anions may contaminate the air supply of PEMFCs that operate on or near the sea, or that power vehicles running on roads where common deicing agents such as CaCl 2 are disseminated. [12] One way to address the issues raised above is to investigate ORR electrocatalysts including Pd-based active sites.…”

Section: Introductionmentioning

confidence: 99%

Interplay between Nitrogen Concentration, Structure, Morphology, and Electrochemical Performance of PdCoNi “Core–Shell” Carbon Nitride Electrocatalysts for the Oxygen Reduction Reaction

et al. 2014

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This report describes the electrochemical behavior of a family of “core‐shell” electrocatalysts consisting of a carbon nitride (CN) “shell” matrix and a “core” of conducting carbon nanoparticles (NPs). The CN “shell” matrix embeds PdCoNi alloy NPs and covers homogeneously the carbon “core”. The chemical composition of the materials is determined by inductively‐coupled plasma atomic emission spectroscopy (ICP‐AES) and microanalysis; the structure is studied by powder X‐ray diffraction (powder XRD); the morphology is investigated by high‐resolution transmission electron microscopy (HR‐TEM). The surface activity and structure are probed by CO stripping. The oxygen reduction reaction (ORR) kinetics, reaction mechanism, and tolerance towards contamination from chloride anions are evaluated by cyclic voltammetry with the thin‐film rotating ring‐disk electrode (CV‐TF‐RRDE) method. The effect of N concentration in the matrix (which forms “coordination nests” for the Pd‐based alloy NPs bearing the active sites) on the ORR performance of the electrocatalysts is described. Results show that N atoms: 1) influence the evolution of the structure of the materials during the preparation processes, and 2) interact with alloy NPs, affecting the bifunctional and electronic ORR mechanisms of active sites and the adsorption/desorption processes of oxygen molecules and contaminants. Finally, the best PdCoNi electrocatalyst shows a higher surface activity in the ORR at 0.9 V vs. RHE with respect to the Pt‐based reference (388 μA cmPd‐2 vs. 153 μA cmPt‐2).

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“…[10][11][12][13][14][15][16][17][18][19][20][21] Feliu et al, Abruna et al, and others have extensively investigated the influence of halides (I − , Br − , Cl − ) on platinum single crystal electrodes. [22][23][24][25][26][27][28][29][30][31][32][33][34][35] Most of the available surface sensitive techniques were used to elucidate adsorbate coverage and structure. Such techniques, including auger electron spectroscopy (AES), low energy electron diffraction (LEED), second harmonic generation (SHG), surface X-ray scattering (SXS), electrochemical scanning tunneling microscope (ESTM) 31,34 and electrochemical quartz crystal microbalance (EQCM), used to investigate anion adsorption have offered significant insight on the dependence of adsorption process on exposed single crystal orientations.…”

mentioning

confidence: 99%

Recovery of Active Surface Sites of Shape-Controlled Platinum Nanoparticles Contaminated with Halide Ions and Its Effect on Surface-Structure

Devivaraprasad¹,

Kar²,

Leuaa³

et al. 2017

J. Electrochem. Soc.

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The interaction of halide ions (I − , Br − , Cl − ) with well-cleaned faceted platinum (nanocube, cuboctahedral) nanoparticles and platinum polycrystalline is investigated in 0.5 M H 2 SO 4 electrolyte. Under electrochemical conditions, the Pt surface gets poisoned with halide ad-atoms and it causes the attenuation of both hydrogen adsorption/desorption in the lower potential region (0.06-0.4 V) and electroxidation of Pt nanoparticles in the higher potential region (0.6-1.2 V). Above certain concentration (5 × 10 −6 M), the strongly adsorbing I − ions mask the H upd features. On the other hand, Br − and Cl − ions alter the peak features in the H upd region, those are characteristic of different Pt surface sites. On excursion to higher potentials (∼>1.2 V), concurrent halogen evolution, Pt oxidation, and oxygen evolution are observed; the increase in peak intensity in the H upd region reflects the reconstruction of the Pt surface. To remove the adsorbed halide ions from the Pt surface, an in-situ potentiostatic method is employed, which involves holding the working electrode at ∼0.03 V in 0.1 M NaOH solution. The cleanliness and retention of surface-structure are confirmed from the voltammograms recorded in the test electrolyte and the recovery of oxygen reduction reaction (ORR) activity after cleaning the Br − ion-contaminated Pt surface supports this conjecture. Anions specifically adsorbed on precious metal surfaces adversely impact several electrochemical reactions including oxidation/ reduction, metal deposition, corrosion and dissolution.1-6 Catalyst poisoning by the adsorbed anions (halides, sulfates and others) is a well-known phenomenon and it decreases the activity of electrocatalysts; for example, in fuel-cell, batteries and electrolyzers. 7,8 Especially platinum, a material for catalyzing a variety of electrochemical reactions, is prone to get poisoned in the presence of adatoms/adsorbates/solution anions under electrochemical conditions. Thus, oxygen reduction reaction (ORR) in fuel cells is affected by the adsorbed species or impurities and it is highly dependent on the cleanliness and surface structure of the catalyst. [9][10][11][12][13] In hydrogen-bromine fuel cells, bromides and bromine species migrate across the membrane and poison the hydrogen-electrode catalyst; moreover, Pt dissolves in Br − ion-containing solutions. 22-35 Most of the available surface sensitive techniques were used to elucidate adsorbate coverage and structure. Such techniques, including auger electron spectroscopy (AES), low energy electron diffraction (LEED), second harmonic generation (SHG), surface X-ray scattering (SXS), electrochemical scanning tunneling microscope (ESTM) 31,34 and electrochemical quartz crystal microbalance (EQCM), used to investigate anion adsorption have offered significant insight on the dependence of adsorption process on exposed single crystal orientations. Thus, AES/LEED studies revealed that Cl − ion adsorption occurs on Pt(100) surface at lower potential than that with Pt(111) surfaces, indi...

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The effect of specific chloride adsorption on the electrochemical behavior of ultrathin Pd films deposited on Pt() in acid solution

Abstract: The electrochemical behavior of thin Pd films supported on a Pt (111)

Cited by 79 publications

References 39 publications

On the oxygen reduction reaction in phosphoric acid electrolyte: Evidence of significantly increased inhibition at steady state conditions

On the oxygen reduction reaction in phosphoric acid electrolyte: Evidence of significantly increased inhibition at steady state conditions

Interplay between Nitrogen Concentration, Structure, Morphology, and Electrochemical Performance of PdCoNi “Core–Shell” Carbon Nitride Electrocatalysts for the Oxygen Reduction Reaction

Recovery of Active Surface Sites of Shape-Controlled Platinum Nanoparticles Contaminated with Halide Ions and Its Effect on Surface-Structure

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