CO and methanol electrooxidation on Pt/Ir/Pt multilayers electrodes

Freitas, Renato G.; Antunes, E.P.; Pereira, Ernesto C.

doi:10.1016/j.electacta.2008.07.073

Cited by 50 publications

(20 citation statements)

References 46 publications

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“…Binary or ternary Pt alloy NPs with Ir showed excellent catalytic activities for electro-oxidation of ammonia [34][35][36][37][38], methanol [39][40][41], formic acid [33,42] and ORR [43]. Vidal-Iglesias et al [38] found that Pt 75 Ir 25 NPs showed, in the low potential range, an enhancement of the ammonia oxidation current compared with the pure Pt NPs prepared by the same method.…”

Section: Introductionmentioning

confidence: 99%

Shape-controlled synthesis of Pt-Ir nanocubes with preferential (100) orientation and their unusual enhanced electrocatalytic activities

Zhong

Liu

et al. 2014

Sci. China Mater.

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Pt-Ir nanocubes with (100)-terminated facets were synthesized for the first time and their unusual high electrocatalytic activity for a model reaction (i.e., ammonia oxidation) was reported. The key parameters in controlling the shape of the PtIr nanocubes were systematically investigated by transmission electron microscopy (TEM). The electrocatalytic activities of the prepared Pt-Ir and pure Pt nanoparticles (NPs) were characterized by cyclic voltammetry (CV). The results showed that the amount of W(CO) 6 and the volume ratio of oleylamine and oleic acid play a significant role in the development of well-defined Pt-Ir nanocubes. The resultant Pt-Ir nanocubes exhibit (100) orientation, which has been confirmed by not only the structural characterization results from high-resolution TEM (HRTEM) and X-ray diffraction (XRD) but also hydrogen desorption profiles obtained from the CV measurements in H 2 SO 4 solution. Lattice contraction of the Pt-Ir nanocubes were suggested by HRTEM and XRD measurements, and the electronic interactions between Pt and Ir in the Pt-Ir nanocubes were demonstrated by X-ray photoelectron spectroscopy. The Pt-Ir nanocubes show higher specific activity than pure Pt nanocubes and much higher specific activity than the polycrystalline Pt-Ir NPs. The much improved specific activity of the Pt-Ir nanocubes could be attributed to the reason that the introduction of Ir in the Pt-Ir nanocubes largely maintains the highly active Pt (100) sites and thus a positive synergistic effect through the addition of Ir to Pt could be achieved due to the possible bifunctional mechanism and the electronic effect.

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Section: Introductionmentioning

confidence: 99%

Shape-controlled synthesis of Pt-Ir nanocubes with preferential (100) orientation and their unusual enhanced electrocatalytic activities

Zhong

Liu

et al. 2014

Sci. China Mater.

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“…Analyzing the charge transfer resistance, it is possible to note that the diameters of the impedance arcs are higher for Pt pc (22,432 Ωcm 2 ) than for Pt pc /Bi 0.58ML (12,235 Ωcm 2 ) and Pt pc /Bi 0.34ML (8,383 Ωcm 2 ) electrodes, suggesting higher electron transfer kinetics on prepared electrodes than Pt pc [58]. The Pt pc /Bi 0.92 ML (108,740 Ωcm 2 ) sample presents the highest charge transfer resistance, even compared with Pt pc , most of the surface of which is expected to be covered with Bi.…”

Section: Methodsmentioning

confidence: 99%

“…Electrochemical impedance spectroscopy is a powerful, rapid, and accurate non-destructive method for the evaluation of a wide range of materials that has been applied to electrocatalysis studies in a number of recent papers [12,24,49,50]. One of the purposes of employing EIS is to obtain the electrocatalytic activity in terms of charge transfer resistance (R ct ).…”

Section: Methodsmentioning

confidence: 99%

“…Hence, much fundamental work has been developed to explore the role of defects, adatoms, and also different materials for the oxidation of ethanol molecules [7,8]. In this sense, low dimensional systems, such as monolayers [9] and metallic multilayers [10][11][12][13], have been proposed as a new kind of material, in which both electronic and structural properties are different from the metallic (or alloy) form. Furthermore, in recent years, the submonolayer catalyst concept has received much attention regarding its use for achieving ultimate reduction of catalyst loading without a sacrifice in activity.…”

Section: Introductionmentioning

confidence: 99%

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Ethanol Electrooxidation on Bi Submonolayers Deposited on a Pt Electrode

et al. 2011

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Bismuth submonolayers covering polycrystalline platinum-surface electrodes have been prepared with several degrees of Bi covering 0.34, 0.58, and 0.92 monolayers, respectively. These samples were used to investigate ethanol electrooxidation using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Suppression of hydrogen adsorption was observed as the degree of Bi covering on the Pt surface increased. Ethanol electrooxidation increased 5.5-fold for Pt/Bi 0.34ML compared with Pt using constant potential polarization at 0.5 V. Electrochemical impedance experiments showed that Pt/Bi 0.34ML electrodes exhibited the lowest charge transfer resistance, which is in agreement with voltammetric and chronoamperometric measurements.

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“…It may be show that the activity of PtRu/C for intermediate of oxidation ethylene glycol is lower than that of ordered intermetallic compound PtPb/C-b catalyst. In many reports [45,46], the capacitive character of absorbed intermediate is also expressed in terms of a CPE. The impedance can be expressed in terms of a CPE as Z Q = (1/Y 0 ) (jω) −n .…”

Section: Electrochemical Behaviormentioning

confidence: 99%