Active surface area determination of Pd-Si alloys by H-adsorption

Correia, Adriana N.; Mascaro, Lúcia H.; Machado, Sérgio Antônio Spínola; Avaca, Luís Alberto

doi:10.1016/s0013-4686(96)00232-0

Cited by 119 publications

(73 citation statements)

References 15 publications

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“…As can be seen in Fig. 4, the anodic sweep presents one peak at approximately 1.0 V, similar on both electrodes, which corresponds to the oxidation of HCHO to CO ads or CHO ads in accordance with reactions (11)(12)(13). After this peak, the next electrochemical process of interest is the generation of CO 2 , indicated by the sharp increase in anodic currents.…”

Section: Formaldehyde Oxidationmentioning

confidence: 65%

“…The method of calculation of electroactive areas and other experimental details are given elsewhere 11 . The electrolytes were prepared with H 2 SO 4 (suprapur Merck, Darmstadt) and Milli-Q water (Millipore, USA) as 0.5 M solutions.…”

Section: Methodsmentioning

confidence: 99%

“…In fact, studies on the oxide formation on amorphous Pd(Si) alloys 11 showed that the first (hydroxide) layer is not well defined on these surfaces while the second (oxide) layer is more easily reduced than on pure polycrystalline Pd. Therefore, this Pd(Si)O could be sufficiently reactive to undergo a chemical reaction with formic acid present in solution, i.e.,…”

Section: Formic Acid Oxidationmentioning

confidence: 99%

“…When the potential reaches ca. 1.0 V, the oxidation of the Pd surface starts (11) and, consequently, the following reactions in the mechanism that are responsible for the peak at this potential. Provided the inversion potential is not sufficiently positive, the surface remains free from poisons and/or (OH) ads and reactions (11-13) slow down.…”

Section: Formaldehyde Oxidationmentioning

confidence: 99%

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Amorphous palladium-silicon alloys for the oxidation of formic acid and formaldehyde. A voltammetric investigation

Correia¹,

Mascaro²,

Machado³

et al. 1999

J. Braz. Chem. Soc.

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A oxidação eletrocatalítica de ácido fórmico e formaldeído foi estudada por voltametria cíclica sobre eletrodos de Pd e da liga amorfa de Pd(Si), com os resultados obtidos sendo comparados com aqueles similares disponíveis na literatura. A oxidação do HCOOH ocorre sobre Pd por meio de desidrogenação catalítica direta via (:C(OH)2)ads, enquanto que sobre Pd(Si) não existem evidências da formação deste intermediário. Este fenômeno é uma conseqüência da presença de sítios inertes de Si na superfície, que diminui a probabilidade da ocorrência de sítios ativos adjacentes disponíveis para esta adsorção. Em altas concentrações de HCOOH, este intermediário sofre desidratação sobre a superfície de Pd e um pico de oxidação associado ao COads pode ser observado. Para o HCHO, o mecanismo de oxidação sobre os dois eletrodos é similar àqueles já discutidos na literatura para a Pt. Entretanto, os óxidos formados sobre a liga amorfa Pd(Si) são mais reativos que aqueles sobre Pd, afetando, assim, a cinética total do processo para ambas as moléculas orgânicas, o que é evidenciado pelo aumento nas correntes anódicas observado nos voltamogramas.The electrocatalytic oxidation of formic acid and formaldehyde on Pd and on amorphous Pd(Si) was studied by cyclic voltammetry and the results compared with the literature for similar systems. The oxidation of HCOOH on Pd occurs through direct catalytic dehydrogenation via (:C(OH)2)ads while on Pd(Si) this intermediate does not appear to be formed. This is a consequence of the presence of inert Si on the surface that diminishes the probability of adjacent free sites. At high HCOOH concentrations, that intermediate undergoes dehydration on the Pd surface and COads oxidation peak is observed. For HCHO, the oxidation mechanism on both electrode materials appears similar to that previously proposed for Pt. However, the oxides formed on the amorphous Pd(Si) alloy are more reactive than those on Pd thus affecting the overall kinetics of the process for both organic molecules, a fact revealed by the increase in anodic currents observed in the voltammograms.

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Section: Formaldehyde Oxidationmentioning

confidence: 65%

Section: Methodsmentioning

confidence: 99%

Section: Formic Acid Oxidationmentioning

confidence: 99%

Section: Formaldehyde Oxidationmentioning

confidence: 99%

See 2 more Smart Citations

Amorphous palladium-silicon alloys for the oxidation of formic acid and formaldehyde. A voltammetric investigation

Correia¹,

Mascaro²,

Machado³

et al. 1999

J. Braz. Chem. Soc.

Self Cite

View full text Add to dashboard Cite

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“…, which is calculated from the area under the reduction peak of the palladium oxide at À0.27 V vs. Hg/HgO (Fig. 3) [33,34]. In the literature, BET surface areas are more commonly presented than electrochemically-determined surface areas, so it is difficult to compare with other bifunctional oxygen catalysts; BET surface areas of 11 m 2 g À1 for LaNiO 3 The physical properties of the carbon support material, C, as well as the gas-diffusion layer carbon C1, are shown in Table 1.…”

Section: Characteristics Of the Pd/c Catalystmentioning

confidence: 99%

A nanostructured bifunctional Pd/C gas-diffusion electrode for metal-air batteries

McKerracher

Alegre

Baglio

et al. 2015

Electrochimica Acta

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Keywords:bifunctional air electrode palladium catalyst metal-air battery A B S T R A C T Designing a bifunctional air electrode which catalyses both the oxygen reduction and oxygen evolution reactions is an essential part of progress towards fully rechargeable metal-air batteries, such as the ironair battery which is environmentally friendly, low cost, and does not suffer risk of thermal runaway like lithium-ion batteries. This paper reports the development of a lightweight carbon-based bifunctional air electrode, catalysed by a small (0.5 mg cm À2 ) loading of 30 wt.% palladium on carbon. The Pd-catalysed air electrode showed good bifunctional activity, with 0.53 V potential difference between oxygen reduction and evolution. The Pd/C air electrode showed improved catalytic activity at high current densities (! 50 mA cm À2) and enhanced durability compared with two commercial Pt/C air electrodes produced by Gaskatel GmbH and Johnson Matthey. A stable oxygen evolution potential was maintained over 1,000 charge-discharge cycles.Crown

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Synthesis of CeO_x‐Decorated Pd/C Catalysts by Controlled Surface Reactions for Hydrogen Oxidation in Anion Exchange Membrane Fuel Cells

Singh

Davydova

Douglin

et al. 2020

Adv Funct Materials

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Due to the sluggish kinetics of the hydrogen oxidation reaction (HOR) in alkaline electrolytes, the development of more efficient HOR catalysts is essential for the next generation of anion‐exchange membrane fuel cells (AEMFCs). In this work, CeOx is selectively deposited onto carbon‐supported Pd nanoparticles by controlled surface reactions, aiming to enhance the homogenous distribution of CeOx and its preferential attachment to Pd nanoparticles, to achieve highly active CeOx‐Pd/C catalysts. The catalysts are characterized by inductively coupled plasma–atomic emission spectroscopy, X‐ray diffraction, high‐resolution transmission electron microscopy, scanning transmission electron microscopy (STEM), electron energy loss spectroscopy, and X‐ray photoelectron spectroscopy to confirm the bulk composition, phases present, morphology, elemental mapping, local oxidation, and surface chemical states, respectively. The intimate contact between Pd and CeOx is shown through high‐resolution STEM maps. The oxophilic nature of CeOx and its effect on Pd are probed by CO stripping. The interfacial contact area between CeOx and Pd nanoparticles is calculated for the first time and correlated to the electrochemical performance of the CeOx‐Pd/C catalysts. Highest recorded HOR specific exchange current (51.5 mA mg−1Pd) and H2–O2 AEMFC performance (peak power density of 1,169 mW cm−2 mgPd−1) are obtained with a CeOx‐Pd/C catalyst with Ce0.38/Pd bulk atomic ratio.

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Active surface area determination of Pd-Si alloys by H-adsorption

Cited by 119 publications

References 15 publications

Amorphous palladium-silicon alloys for the oxidation of formic acid and formaldehyde. A voltammetric investigation

Amorphous palladium-silicon alloys for the oxidation of formic acid and formaldehyde. A voltammetric investigation

A nanostructured bifunctional Pd/C gas-diffusion electrode for metal-air batteries

Synthesis of CeO_x‐Decorated Pd/C Catalysts by Controlled Surface Reactions for Hydrogen Oxidation in Anion Exchange Membrane Fuel Cells

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Active surface area determination of Pd-Si alloys by H-adsorption

Cited by 119 publications

References 15 publications

Amorphous palladium-silicon alloys for the oxidation of formic acid and formaldehyde. A voltammetric investigation

Amorphous palladium-silicon alloys for the oxidation of formic acid and formaldehyde. A voltammetric investigation

A nanostructured bifunctional Pd/C gas-diffusion electrode for metal-air batteries

Synthesis of CeOx‐Decorated Pd/C Catalysts by Controlled Surface Reactions for Hydrogen Oxidation in Anion Exchange Membrane Fuel Cells

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Product

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About

Synthesis of CeO_x‐Decorated Pd/C Catalysts by Controlled Surface Reactions for Hydrogen Oxidation in Anion Exchange Membrane Fuel Cells