DFT study of adsorption of hydrogen and carbon monoxide on PtxBi1−x/Pt(111) bimetallic overlayers: correlation to surface electronic properties

Pašti, Igor A.; Mentus, Slavko

doi:10.1039/b823385c

Cited by 21 publications

(21 citation statements)

References 34 publications

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“…However, the depletion of states within the interval between E F and approximately −1.25 eV is much more pronounced for p-metals than for d-metals. As the same region of d-PDOS is involved in the bonding of many simple adsorbates [9,53], the depletion of states below E F is expected to have the striking effect on the adsorption and, consequently, on the catalytic activity of Pt(1 1 1) surface. Fig.…”

Section: Modification Of Electronic Structure Of Substrate By Adsorbementioning

confidence: 99%

“…For example, Pt-Bi surface alloys over Pt(1 1 1) surface were suggested as possible electrocatalysts for HER [7]. Studies regarding modification of electronic properties of Pt(1 1 1) surface with introduction of different metals in the surface layer could be found in the literature [8] and it is also documented how this modification of electronic structure alters chemical properties of a surface [7,9].…”

Section: Introductionmentioning

confidence: 98%

“…In particular, Kokalj et al [28] demonstrated that Pt(1 1 1) surface can be successfully modeled using bulk truncated static Pt slab. The applicability of described surface slab model has been proven in the previous reports by us [8,9]. Work functions were calculated using following equation:…”

Section: Introductionmentioning

confidence: 99%

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First principles study of adsorption of metals on Pt(111) surface

Pašti

Mentus

2010

Journal of Alloys and Compounds

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Section: Modification Of Electronic Structure Of Substrate By Adsorbementioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

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First principles study of adsorption of metals on Pt(111) surface

Pašti

Mentus

2010

Journal of Alloys and Compounds

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“…24 For the intermetallic structures, Oana et al 21 found that the propensity for CO adsorption on Pt is drastically reduced of PtBi 2 and PtBi surfaces (with respect to Pt) due to an increase of the Fermi level of the system (that determines the occupation of higherlying antibonding orbitals) induced by Bi. The results from Lin et al 23 for the surface coadsorption of CO at Pt surfaces single crystals modified with Bi adatoms suggest that Bi adatom increases the extent of the dπ → 2π* back bonding between Pt and the adsorbed CO stabilizing the CO molecule at the surface.…”

Section: Introductionmentioning

confidence: 98%

Bismuth and CO Coadsorption on Platinum Nanoparticles

et al. 2014

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CO adsorption onto Pt-and Pt-based catalysts is a very relevant topic in electrocatalysis, and in particular, in fuel cells research. CO is known to be the main responsible of the poisoning of the catalysts and consequent decrease on performance of the fuel cells devices. In this paper, density functional theory (DFT) calculations and experiments were combined to access the effect of modifying Pt nanoparticles with Bi on CO adsorption. CO adsorption energies were calculated for Pt sites nearby Bi atoms in different type of structures: Pt clusters with Bi as surface adatom and Pt clusters with Bi as surface and subsurface dopant (alloys). The results show that, when compared with pure Pt, the adsorption energies for CO are lower on PtBi clusters in both adatom and surface alloy configurations. Subsurface PtBi alloys reveal higher adsorption energies for CO but these structures are energetically very unfavorable. On the basis of the calculations, a high degree of mobility of Bi on the surface was found in the presence of CO. These results suggest that the experimental differences between cyclic voltammogram before and after CO stripping can be due to a reorganization of the Bi layer on the catalyst when CO is coadsorbed. It was also experimentally observed, that CO oxidation peaks on the modified electrodes shift to higher potentials with increasing Bi coverage. These results suggest a higher effect of the decrease of CO coverages on the oxidation process than the decrease of the biding energies for Pt−CO in the presence of Bi.

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“…[10][11][12][13] inhibits poison formation and simultaneously enhances dehydrogenation, 13 i.e., this modification is an efficient way to hinder the dehydration path (CO-intermediate pathway) in favor of the direct path. 22,23,32 The origin of its catalytic activity was related to electronic effects. A correlation between ensemble size and formic acid oxidation activity was also established.…”

Section: Introductionmentioning

confidence: 99%

Electrocatalytic properties of Pt-Bi electrodes towards the electrooxidation of formic acid

Lović¹,

Tripković²,

Popović³

et al. 2013

JSCS

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Formic acid oxidation was studied on two Pt-Bi catalysts, Pt2Bi and polycrystalline Pt modified by irreversible adsorbed Bi (Pt/Biirr) in order to establish the difference between the effects of Biirr and Bi in alloyed state. The results were compared to pure Pt. It was found that both bimetallic catalysts were more active than Pt with the onset potentials shifted to more negative values and the currents at 0.0 V vs. SCE (under steady state conditions) improved up to two order of magnitude. The origin of Pt2Bi high activity and stability is increased selectivity toward formic acid dehydrogenation caused by the ensemble and electronic effect and suppression of Bi leaching from the surface during formic acid oxidation. However, although Pt/Biirr also shows remarkable initial activity compared to pure Pt, dissolution of Bi is not suppressed and the poisoning of the electrode surface induced by dehydration path is observed. Comparison of the initial quasi-steady state and potentiodynamic results obtained for these two Pt-Bi catalysts revealed that the electronic effect, existing only in the alloy, contributes earlier start of the reaction, while the maximum current density is determined by the ensemble effect. [Projekat Ministarstva nauke Republike Srbije, br. H-172060

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DFT study of adsorption of hydrogen and carbon monoxide on PtxBi1−x/Pt(111) bimetallic overlayers: correlation to surface electronic properties

Cited by 21 publications

References 34 publications

First principles study of adsorption of metals on Pt(111) surface

First principles study of adsorption of metals on Pt(111) surface

Bismuth and CO Coadsorption on Platinum Nanoparticles

Electrocatalytic properties of Pt-Bi electrodes towards the electrooxidation of formic acid

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