Site Blocking with Gold Adatoms as an Approach to Study Structural Effects in Electrocatalysis

Kuznetsov, A. N.; Зайковский, В. И.; Parmon, Valentin N.; Savinova, Elena R.

doi:10.1007/s12678-012-0104-3

Cited by 9 publications

(7 citation statements)

References 71 publications

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“…11,14,15 Site blocking of the Pt NP surface with Au atoms is expected to be an effective technique for the electrochemical stabilization of coordinatively unsaturated sites at Pt NP surfaces. 16,17 On the basis of first-principles simulations, Wei et al proposed that the corrosion of Pt NPs at the corner and edge sites can be hindered by framing using inert metals, e.g. Au.…”

Section: Introductionmentioning

confidence: 99%

Oxygen reduction reaction activity and structural stability of Pt–Au nanoparticles prepared by arc-plasma deposition

Takahashi

Chiba

Kato

et al. 2015

Phys. Chem. Chem. Phys.

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The oxygen reduction reaction (ORR) activity and durability of various Au(x)/Pt100 nanoparticles (where x is the atomic ratio of Au against Pt) are evaluated herein. The samples were fabricated on a highly-oriented pyrolytic graphite substrate at 773 K through sequential arc-plasma depositions of Pt and Au. The electrochemical hydrogen adsorption charges (electrochemical surface area), particularly the characteristic currents caused by the corner and edge sites of the Pt nanoparticles, decrease with increasing Au atomic ratio (x). In contrast, the specific ORR activities of the Au(x)/Pt100 samples were dependent on the atomic ratios of Pt and Au: the Au28/Pt100 sample showed the highest specific activity among all the investigated samples (x = 0-42). As for ORR durability evaluated by applying potential cycles between 0.6 and 1.0 V in oxygen-saturated 0.1 M HClO4, Au28/Pt100 was the most durable sample against the electrochemical potential cycles. The results clearly showed that the Au atoms located at coordinatively-unsaturated sites, e.g. at the corners or edges of the Pt nanoparticles, can improve the ORR durability by suppressing unsaturated-site-induced degradation of the Pt nanoparticles.

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Section: Introductionmentioning

confidence: 99%

Oxygen reduction reaction activity and structural stability of Pt–Au nanoparticles prepared by arc-plasma deposition

Takahashi

Chiba

Kato

et al. 2015

Phys. Chem. Chem. Phys.

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“…Surface atoms with a lower coordination number have higher surface energies. By blocking these sites with Au (an inert metal), a reduction in degradation can be achieved, and, hence, a better electrochemical durability. Studies were conducted on the theoretical calculations of Au segregation on low‐coordination sites and on the consequences on the stabilization of Pt nanoparticles .…”

Section: Resultsmentioning

confidence: 99%

Gold Doping in PtCu₃/HSAC Nanoparticles and Their Morphological, Structural, and Compositional Changes during Oxygen Reduction Reaction Electrochemical Cycling

et al. 2017

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Pt‐based nanoparticles supported on high‐surface‐area carbon (HSAC) show very good properties as catalysts in polymer electrolyte membrane fuel cells (PEMFC). In many cases, however, the initial high activity of such catalysts rapidly drops as caused by various detrimental phenomena occurring in a typical electrochemical environment. In this work, a detailed study of a highly active system composed of PtCu3/HSAC nanoparticles with partially ordered structure and Pt skin with the addition of Au is performed. By using aberration‐corrected scanning transmission electron microscopy, the effects of adding small amounts of gold compared to the nonmodified sample are followed through the different stages of an electrochemical cycling degradation protocol. Various morphological changes such as faceting, reshaping, and thickening of the Pt skin are investigated for both sets of samples on the atomic level. Interesting features such as well‐defined shapes and surface defects are observed after degradation. However, the most important differences in terms of durability seem related to particle porosity. Finally, the experimental morphological observations are successfully reproduced by dealloying simulation with kinetic Monte Carlo modeling.

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“…8,19 Another way to probe the site-specific catalytic activity is based on blockage of certain types of sites, such as steps/defects, by attaching "non-reactive" foreign atoms on them, leaving the rest of the sites free to interact with the reactive species. [30][31][32][33] In either case, the active site is indirectly identified by means of a notable effect observed in a particular catalytic property, which could be the rate and/or selectivity of a reaction. Although these two procedures described above can be strongly chemically intuitive, they consider that the density of the active sites, or the overall activity, results from a simple linear combination among different facets at the surface.…”

Section: Introductionmentioning

confidence: 99%

“…In the field of electrocatalysis, it often involves introducing specific types of sites on a basal plane, such as locating crystalline (or even ill-defined) steps/defects over the (111) terraces. In this case, the inhibition or increase of catalytic activity is monitored without distinguishing the chemistry at specific electrocatalytic sites. , Another way to probe the site-specific catalytic activity is based on blockage of certain types of sites, such as steps/defects, by attaching “nonreactive” foreign atoms on them, leaving the rest of the sites free to interact with the reactive species. − In either case, the active site is indirectly identified by means of a notable effect observed in a particular catalytic property, which could be the rate and/or selectivity of a reaction. Although these two procedures described above can be strongly chemically intuitive, they consider that the density of the active sites, or the overall activity, results from a simple linear combination among different facets at the surface.…”

Section: Introductionmentioning

confidence: 99%

Identity of the Most and Least Active Sites for Activation of the Pathways for CO₂ Formation from the Electro-oxidation of Methanol and Ethanol on Platinum

et al. 2019

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In the field of the catalysis on solid surfaces, discrimination of the site-specific chemistry taking place on surfaces consisting of multiple types of sites is challenging, especially at electrified solid/liquid interfaces. In this study, site-specific chemical labeling on Pt stepped surfaces was achieved by attaching the 13 CO species exclusively on the top side of the (110) steps, while maintaining all the (111) sites available. The catalysts were then employed in a spectro-electrochemical study of the electro-oxidation of methanol and ethanol. The onset potentials for the formation of 13 CO 2 and 12 CO 2 revealed the existence of two channels of carbon dioxide formation, separated by about 0.22 V, on the same Pt surface. The active sites with lower over-potential requirement (or lower energy input) for activation of the reaction pathway of CO 2 formation resided on the (111) terraces. On the other hand, the active sites with higher over-potential requirement (or higher energy input) for activation of the reaction pathway for electro-oxidation of 13 CO ads species to 13 CO 2 were at the top of the (110) steps.The findings revealed the identities of the most active sites and least active sites involved in the formation of CO 2 during the electro-oxidation of alcohols. On Pt surfaces, the complex interplay involving the steps on the surface favors activation of the pathways for CO ads oxidation on the (111) terraces, rather than promoting reaction steps directly on the steps themselves.

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Site Blocking with Gold Adatoms as an Approach to Study Structural Effects in Electrocatalysis

Cited by 9 publications

References 71 publications

Oxygen reduction reaction activity and structural stability of Pt–Au nanoparticles prepared by arc-plasma deposition

Oxygen reduction reaction activity and structural stability of Pt–Au nanoparticles prepared by arc-plasma deposition

Gold Doping in PtCu₃/HSAC Nanoparticles and Their Morphological, Structural, and Compositional Changes during Oxygen Reduction Reaction Electrochemical Cycling

Identity of the Most and Least Active Sites for Activation of the Pathways for CO₂ Formation from the Electro-oxidation of Methanol and Ethanol on Platinum

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Site Blocking with Gold Adatoms as an Approach to Study Structural Effects in Electrocatalysis

Cited by 9 publications

References 71 publications

Oxygen reduction reaction activity and structural stability of Pt–Au nanoparticles prepared by arc-plasma deposition

Oxygen reduction reaction activity and structural stability of Pt–Au nanoparticles prepared by arc-plasma deposition

Gold Doping in PtCu3/HSAC Nanoparticles and Their Morphological, Structural, and Compositional Changes during Oxygen Reduction Reaction Electrochemical Cycling

Identity of the Most and Least Active Sites for Activation of the Pathways for CO2 Formation from the Electro-oxidation of Methanol and Ethanol on Platinum

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Gold Doping in PtCu₃/HSAC Nanoparticles and Their Morphological, Structural, and Compositional Changes during Oxygen Reduction Reaction Electrochemical Cycling

Identity of the Most and Least Active Sites for Activation of the Pathways for CO₂ Formation from the Electro-oxidation of Methanol and Ethanol on Platinum