Positive Effect of Surface Doping with Au on the Stability of Pt-Based Electrocatalysts

Gatalo, Matija; Jovanovič, Primož; Polymeros, George; Grote, Jan-Philipp; Pavlišič, Andraž; Ruiz-Zepeda, Francisco; Šelih, Vid Simon; Šala, Martin; Hočevar, Samo B.; Bele, Marjan; Mayrhofer, Karl Johann Jakob; Hodnik, Nejc; Gaberšček, Miran

doi:10.1021/acscatal.5b02883

Cited by 95 publications

(133 citation statements)

References 42 publications

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“…8. In the IL-STEM images, the formation of more defined edges and also facets is seen (i.e., faceting) [13,16]. This is in accordance with Fig.…”

Section: Figure 6 Il-stem Edx Line Scan (Top) Haadf Image (Middle) supporting

confidence: 89%

“…Careful inspection of the IL-STEM HAADF (yellow dot circle around the particle in Fig. 7) also reveals small shrinkage and the formation of facets [13]. EDX Cu line profile indicates that negligible amount of Cu was removed at the activation protocol, unlike in the case of the Pt-doped sample.…”

Section: Figure 6 Il-stem Edx Line Scan (Top) Haadf Image (Middle) mentioning

confidence: 95%

“…It can increase the internal resistance of polymer membrane and can also poison the electrocatalyst active Pt surface [1][2][3][4]. And on the other hand, retention of Cu is essential to sustain enhanced ORR activity via ligand and/or strain effects [13]. The negative effect of Cu dealloying under long-term PEM FC operating conditions (e.g., simulated via degradation protocol of 50 000 cycles, 0.4 -1.0 V RHE , 1 V s -1 ) can be visible in the change of the slope of ORR polarization curve (Fig.…”

Section: Figure 1 (A) First Cyclic Voltammogram Of Ea Of (I) As-prepmentioning

confidence: 99%

“…However, their stability is still under debate and is the topic of many current and future studies [13][14][15][16][17][18][19][20]. Three issues are foreseen for Ptalloys: (i) loss of initially superior ORR activity [13], (ii) formation of unstable porous nanoparticles [9,15] and (iii) poisoning of the PEM FC by the leached less noble metal cations [12,[21][22][23]. It is known that leached metals can cause the increase of the resistance of the polymer membrane and the lowering of the performance of the anode electrocatalysts due to the poisoning of the Pt surface [12,23].…”

Section: Introductionmentioning

confidence: 99%

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Insights into electrochemical dealloying of Cu out of Au-doped Pt-alloy nanoparticles at the sub-nano-scale

Gatalo

Jovanovič

Ruiz-Zepeda

et al. 2018

J. Electrochem. Sci. Eng.

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“…8. In the IL-STEM images, the formation of more defined edges and also facets is seen (i.e., faceting) [13,16]. This is in accordance with Fig.…”

Section: Figure 6 Il-stem Edx Line Scan (Top) Haadf Image (Middle) supporting

confidence: 89%

Section: Figure 6 Il-stem Edx Line Scan (Top) Haadf Image (Middle) mentioning

confidence: 95%

Section: Figure 1 (A) First Cyclic Voltammogram Of Ea Of (I) As-prepmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Insights into electrochemical dealloying of Cu out of Au-doped Pt-alloy nanoparticles at the sub-nano-scale

Gatalo

Jovanovič

Ruiz-Zepeda

et al. 2018

J. Electrochem. Sci. Eng.

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“…PtAu shells have also been used to fabricate core-shellstructured electrocatalysts [222,238,558] and the choice of using Au is based on its ability to greatly enhance stabilities through the modification of Pt electronic structures. In addition, there have also been various reports related to the introduction of other precious metals such as Ag into the shells of electrocatalysts for ORRs [107].…”

Section: Core-shell-structured Catalysts With Alloy Shellsmentioning

confidence: 99%

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

Wang

Luo

et al. 2018

Electrochem. Energ. Rev.

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Pt-based catalysts are the most efficient catalysts for low-temperature fuel cells. However, commercialization is impeded by prohibitively high costs and scarcity. One of the most effective strategies to reduce Pt loading is to deposit a monolayer or a few layers of Pt over other metal cores to form core-shell-structured electrocatalysts. In core-shell-structured electrocatalysts, the compositions of the core can be divided into five classes: single-precious metallic cores represented by Pd, Ru, and Au; singlenon-precious metallic cores represented by Cu, Ni, Co, and Fe; alloy cores containing 3d, 4d or 5d metals; and carbide and nitride cores. Of these, researchers have found that carbide and nitride cores can yield tremendous advantages over alloy cores in terms of cost and promotional activities of Pt shells. In addition, desirable shells with reasonable thicknesses and compositions have been recognized to play a dominant role in electrocatalytic performances. And recently, researchers have also found that the catalytic activity of core-shell-structured catalysts is dependent on the binding energy of the adsorbents, which is determined by the d-band center of Pt. The shifting of this d-band center in turn is mainly affected by strain and electronic effects, which can be adjusted by adjusting core compositions and shell thicknesses of catalysts. In the development of these core-shell structures, optimal synthesis methods are of primary concern because they directly determine the practical application potential of the resulting electrocatalysts. And in this article, the principles behind core-shell-structured low-Pt electrocatalysts and the developmental progresses of various synthesis methods along with the traits of each type of core and its effects on Pt shell catalytic activities are discussed. In addition, perspectives on this type of catalyst are discussed and future research directions are proposed.

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The Influence of Gold on Corrosion Resistance of P t C u3/ C Nanoparticles Composite

Ruiz‐Zepeda

Gatalo

Jovanovič

et al. 2016

European Microscopy Congress 2016: Proceedings

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One of the applications of Pt‐based nanoparticles on high surface area carbon (HSAC) support composites is as a catalyst in polymer electrolyte membrane fuel cells (PEMFC) [1]. Yet the full commercial implementation of the technology has been hindered by the composite cathode which exhibits a low catalytic activity for oxygen reduction reaction (ORR), a poor stability in electrochemical environment and is expensive due to use of Pt. One solution to those issues is to alloy Pt with other transitional metals, which will not only reduce the composite costs, but also increase the catalytic activity for ORR [2]. Chemical ordering of the Pt‐M/HSAC (M=Metal) composite has shown to improve the stability of the nanoparticles, as well as to enhance the catalytic activity for ORR. [3]. Recent work has shown that adding a small amount of gold can improve the durability of Pt and Pt‐based nanoparticles [4,5], as well as inhibit the oxidation of HSAC support [5]. We have used Aberration Corrected Scanning Transmission Electron Microscopy (AC‐STEM) to study the effect of gold on the Pt‐skin partially ordered intermetallic PtCu 3 /HSAC composite. Au doped PtCu 3 /C and PtCu 3 /C composites were compared side to side, before and after an electrochemical cycling treatment. Fig. 1 shows scanning transmission electron microscopy annular dark filed images and energy dispersive x‐rays maps of the two composites after 200 cycles of electrochemical activation (EA, 0.05 – 1.35 V RHE , 300 mVs ‐1 ). Less porous nanoparticles and lower Cu dissolution are observed in the Au doped PtCu 3 /C composite. Surface modifications were also observed in non‐porous nanoparticles after performing 10 000 cycles of severe degradation (0.4 – 1.4 V, 1 Vs ‐1 ): (1) thickening of the Pt skin, (2) faceting and (3) surface dislocations (Fig. 2). These surface modifications may have influence on stress and nanoparticle stability. Overall, the Au doped PtCu 3 /C composite exhibited higher Cu retention and better durability compared to its binary analogue.

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Positive Effect of Surface Doping with Au on the Stability of Pt-Based Electrocatalysts

Cited by 95 publications

References 42 publications

Insights into electrochemical dealloying of Cu out of Au-doped Pt-alloy nanoparticles at the sub-nano-scale

Insights into electrochemical dealloying of Cu out of Au-doped Pt-alloy nanoparticles at the sub-nano-scale

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

The Influence of Gold on Corrosion Resistance of P t C u3/ C Nanoparticles Composite

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