Catalysis of hydrogen evolution on different Pd/Au(111) nanostructures in alkaline solution

Smiljanić, Milutin; Srejić, Irina; Grgur, Branimir N.; Rakočević, Zlatko Lj.; Štrbac, Svetlana

doi:10.1016/j.electacta.2012.10.128

Cited by 37 publications

(23 citation statements)

References 30 publications

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“…One well defined Tafel slope of −170 mV/dec is obtained for HER on Au(111), suggesting that reaction takes place through parallel Volmer-Tafel mechanism under Temkin conditions. 60 For both Rh(poly) and Pt(poly) electrodes, Tafel slope of −60 mV/dec can be assigned to Volmer-Tafel pathway with the Tafel step as the rate determining. 61,62 For HER on Rh/Au(111) electrode, Tafel slope of −120 mV/dec can be assigned to the Volmer-Tafel mechanism with the Volmer step as the rate determining, or to the Volmer-Heyrovsky pathway, which can be operative on Rh electrodes.…”

Section: Resultsmentioning

confidence: 99%

Spontaneously Deposited Rh on Au(111) Observed by AFM and XPS: Electrocatalysis of Hydrogen Evolution

Štrbac

Smiljanić

Rakočević

2016

J. Electrochem. Soc.

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Rhodium nanoislands were spontaneously deposited on Au(111) up to a full coverage. Obtained Rh/Au(111) bimetallic surface was characterized ex situ by Atomic Force Microscopy imaging and by X-Ray Photoelectron Microscopy, while in situ characterization was performed by Cyclic Voltammetry in 0.1 M NaOH solution. Pronounced catalysis of hydrogen evolution reaction has been observed on Rh modified Au(111) surface compared to bare Au(111). This is ascribed to the suitable geometry of obtained Rh/Au(111) nanostructured electrode surface providing large number of active sites and to the electronic interaction between Au(111) substrate and Rh deposit.Bimetallic electrodes consisting of noble metal substrate modified by a foreign metal deposit are still in the focus of interest in electrocatalysis starting from early publications. 1-4 Tailoring bimetallic electrodes with pronounced electrocatalytic activity compared to the activity of the substrate alone or to the both constituting metals is a demanding task regarding the chemical nature and the structure of the substrate and deposit, which should result in improved surface chemistry and geometry with respect to the active surface sites and/or to the electronic effect. Well-ordered noble metal electrodes modified by submonolayer to a few layers thick deposit of highly active metals from platinum group are the most convenient bimetallic model systems for fundamental studies of the electrocatalytic activity of such various nanostructures for fuel cell reactions. [5][6][7] Structural, electronic and chemical properties of well-defined bimetallic surfaces are examined ex situ by common techniques including Scanning Probe Microscopy (SPM), and X-ray Photoelectron Spectroscopy (XPS). 8,9 With the advent of in situ microscopic and spectroscopic techniques, such as Scanning Tunneling Microscopy (STM), 10 XPS, 11 Surface X-ray Scattering (SXS) and X-ray Absorption Spectroscopy (XAS), 12 it became possible to observe the structure of bimetallic surface and to determine its chemical composition and oxidation state of constituting metals under defined electrochemical conditions or during electrocatalytic reactions.For the preparation of bimetallic electrodes with well-defined structure, various deposition methods were employed including electrochemical deposition on nonreconstructed 13 or reconstructed single crystal surfaces, 14 surface limited redox replacement, 15-18 defectmediated growth, 19 and spontaneous deposition. 20,21 The spontaneous deposition method, which is explored in this work, assumes several processes that occur on the electrode surface during its immersion into the depositing metal ions solution at open circuit potential. These involve either irreversible adsorption of metal ion complexes or electroless deposition in which depositing metal ions are reduced by substrate atoms which are oxidized, or a combination of both. Finally obtained bimetallic surface consists of three-dimensional foreign metal nanoislands with the coverage up to a monolayer. In some cases, w...

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Section: Resultsmentioning

confidence: 99%

Spontaneously Deposited Rh on Au(111) Observed by AFM and XPS: Electrocatalysis of Hydrogen Evolution

Štrbac

Smiljanić

Rakočević

2016

J. Electrochem. Soc.

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“…38,[201][202][203][204][205][206] Nørskov's group reported the HER activity for metals and over 700 binary alloys, and presented a volcano plot using experimentally measured logj 0 against the DFT calculated Gibbs energy of hydrogen adsorption (∆G H* , Figure 11a). 38,207 In particular, the optimum value should be around ∆G H* = 0, and BiPt was found to have an activity comparable to, or even better than pure Pt (Figure 11b).…”

Section: Traditional Her Catalystsmentioning

confidence: 99%

Heteroatom-Doped Graphene-Based Materials for Energy-Relevant Electrocatalytic Processes

et al. 2015

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To address the aggravating energy and environment issues, the cheap, highly active, and durable electrocatalysts as noble metal substitutes both at the anode and cathode are actively pursued. Among them, heteroatom-doped graphene-based materials show extraordinary electrocatalytic performance, some even close to or outperforming the state-of-the-art noble metals such as Pt and IrO 2 -based materials. This review provides a concise appraisal on graphene doping methods, the possible doping configurations and their unique electrochemical properties, including single-and double-doping with N, B, S, and P. In addition, heteroatom-doped graphene-based materials are reviewed as electrocatalysts for oxygen reduction (ORR), hydrogen evolution (HER), and oxygen evolution reactions (OER) in terms of their electrocatalytic mechanisms and performance. Significantly, three-dimensional (3D) heteroatom-doped graphene structures have been discussed, especially those that can be directly utilized as catalyst electrodes without extra binders and supports.

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“…1,31,[33][34][35][36][37][38][39][40] Several series of bimetallic surfaces in two typical configurations, as illustrated in Figure 1, are considered, including, in particular, All systems are calculated using density-functional theory (DFT) with the Perdew-Burke-Ernzerhof 41 (PBE) generalized gradient approximation (GGA) as implemented in the Quantum ESPRESSO (QE) package. 42 We use an energy cutoff of 60 Ry for the plane-wave basis and a 14 × 14 × 1 Monkhorst-Pack 43 k-mesh for the Brillouin zone integration.…”

Section: Model Systems and Computational Detailsmentioning

confidence: 99%

Theoretical studies of the work functions of Pd-based bimetallic surfaces

Ding

Wang

et al. 2015

The Journal of Chemical Physics

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Work functions of Pd-based bimetallic surfaces, including mainly M/Pd(111), Pd/M, and Pd/M/Pd(111) (M = 4d transition metals, Cu, Au, and Pt), are studied using density functional theory. We find that the work function of these bimetallic surfaces is significantly different from that of parent metals. Careful analysis based on Bader charges and electron density difference indicates that the variation of the work function in bimetallic surfaces can be mainly attributed to two factors: (1) charge transfer between the two different metals as a result of their different intrinsic electronegativity, and (2) the charge redistribution induced by chemical bonding between the top two layers. The first factor can be related to the contact potential, i.e., the work function difference between two metals in direct contact, and the second factor can be well characterized by the change in the charge spilling out into vacuum. We also find that the variation in the work functions of Pd/M/Pd(111) surfaces correlates very well with the variation of the d-band center of the surface Pd atom. The findings in this work can be used to provide general guidelines to design new bimetallic surfaces with desired electronic properties.

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Catalysis of hydrogen evolution on different Pd/Au(111) nanostructures in alkaline solution

Cited by 37 publications

References 30 publications

Spontaneously Deposited Rh on Au(111) Observed by AFM and XPS: Electrocatalysis of Hydrogen Evolution

Spontaneously Deposited Rh on Au(111) Observed by AFM and XPS: Electrocatalysis of Hydrogen Evolution

Heteroatom-Doped Graphene-Based Materials for Energy-Relevant Electrocatalytic Processes

Theoretical studies of the work functions of Pd-based bimetallic surfaces

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