Structure evolution of Pt–3d transition metal alloys under reductive and oxidizing conditions and effect on the CO oxidation: a first-principles study

Su, Hai‐Yan; Gu, Xiang-Kui; Ma, Xingxiao; Zhao, Yue; Bao, Xinhe; Li, Wei‐Xue

doi:10.1016/j.cattod.2010.10.069

Cited by 35 publications

(31 citation statements)

References 51 publications

(68 reference statements)

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“…This implies that in the absence of oxygen adsorption, Pt atoms tend to segregate to the surface. This is understandable because the surface energy of Pt(111) is lower than that of Ni(111) [32]. As seen in Fig.…”

Section: Segregation Energy and Oxygen-metal Bindingmentioning

confidence: 67%

An atomistic thermodynamics study of the structural evolution of the Pt3Ni(111) surface in an oxygen environment

Sun

Zhao

et al. 2013

Chinese Journal of Catalysis

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The structural evolution of the Pt3Ni(111) surface under oxidizing conditions was studied by ab initio atomistic thermodynamics. The thermodynamic phase diagram from Ni-rich to Pt-rich conditions with oxygen coverages up to one monolayer was constructed from their 560 possible surface structures. With an increase in the oxygen chemical potential, there were only two types of thermodynamically stable structures, which were a clean Pt-skin surface and a Ni-skin surface with chemisorbed oxygen, regardless of the underlying Pt-rich or Ni-rich conditions. Bimetallic surfaces with chemisorbed oxygen were only metastable. The detail analysis revealed that the structural evolution is determined by the factors of segregation cost, difference between oxygen-metal (Pt and Ni) bonding strength, and oxygen chemical potential.

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Section: Segregation Energy and Oxygen-metal Bindingmentioning

confidence: 67%

An atomistic thermodynamics study of the structural evolution of the Pt3Ni(111) surface in an oxygen environment

Sun

Zhao

et al. 2013

Chinese Journal of Catalysis

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“…12 We also studied O 2 dissociation on Pt(111) and a Pt-skin layer on Pt 3 Ni, and a similar trend (0.71 eV on Pt(111) vs 0.97 eV on the Pt-skin) was found. 51,74 On the other hand, adsorption of CO, H, O, and O 2 on Pt-skin surfaces is weakened by the subsurface TMs, 9,10,32,[51][52][53]60 but the destabilization occurs with a similar magnitude. 44,51 For example, binding energies of CO and O 2 on a Pt-skin with subsurface Ru are -1.25 and -0.26 eV, respectively, compared to -1.82 eV/CO and -0.65 eV/O 2 on Pt(111).…”

Section: ' Introductionmentioning

confidence: 99%

Synergetic Effect of Surface and Subsurface Ni Species at Pt−Ni Bimetallic Catalysts for CO Oxidation

et al. 2011

J. Am. Chem. Soc.

269

193

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Various well-defined Ni-Pt(111) model catalysts are constructed at atomiclevel precision under ultra-high-vacuum conditions and characterized by X-ray photoelectron spectroscopy and scanning tunneling microscopy. Subsequent studies of CO oxidation over the surfaces show that a sandwich surface (NiO 1-x /Pt/Ni/Pt(111)) consisting of both surface Ni oxide nanoislands and subsurface Ni atoms at a Pt(111) surface presents the highest reactivity. A similar sandwich structure has been obtained in supported Pt-Ni nanoparticles via activation in H 2 at an intermediate temperature and established by techniques including acid leaching, inductively coupled plasma, and X-ray adsorption nearedge structure. Among the supported Pt-Ni catalysts studied, the sandwich bimetallic catalysts demonstrate the highest activity to CO oxidation, where 100% CO conversion occurs near room temperature. Both surface science studies of model catalysts and catalytic reaction experiments on supported catalysts illustrate the synergetic effect of the surface and subsurface Ni species on the CO oxidation, in which the surface Ni oxide nanoislands activate O 2 , producing atomic O species, while the subsurface Ni atoms further enhance the elementary reaction of CO oxidation with O.

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“…As well known, the stability in electrochemistry is one of the critical factors to consider for its successful application to fuel cell. Consequently, the issues of surface segregation of TM in Pt 3 TM system and its loss of reactivity have become the most important problems to resolve [7,8]. Previously, the stability of Pt-3d TM system was investigated with DFT calculation, showing the structural evolution under various reaction conditions [7].…”

mentioning

confidence: 99%

Surface segregation and oxidation of Pt3Ni(1 1 1) alloys under oxygen environment

et al. 2016

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a b s t r a c tUtilizing ambient pressure X-ray photoelectron spectroscopy (AP-XPS), the surface segregation and oxidation of Pt 3 Ni(1 1 1) alloys are investigated as a function of temperature and oxygen pressure. The in situ AP-XPS measurements of oxygen oxidation process show that the Pt "skin" surface is not stable under the exposure of oxygen pressure of 100 mTorr at room temperature. As the temperature and pressure are elevated, the formations of Ni 2 O 3 , NiO x , and NiO are observed on surface while Pt atom starts to reduce its adsorbed oxygen, which is a clear sign of surface segregation of Ni to surface. Upon the evacuation of oxygen gas, i.e. ultrahigh vacuum condition, both of NiO x and NiO oxide get reduced and Ni 2 O 3 remains on the surface. The DFT calculation is employed to explain the formation of surface oxides under oxidation condition.

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Structure evolution of Pt–3d transition metal alloys under reductive and oxidizing conditions and effect on the CO oxidation: a first-principles study

Cited by 35 publications

References 51 publications

An atomistic thermodynamics study of the structural evolution of the Pt3Ni(111) surface in an oxygen environment

An atomistic thermodynamics study of the structural evolution of the Pt3Ni(111) surface in an oxygen environment

Synergetic Effect of Surface and Subsurface Ni Species at Pt−Ni Bimetallic Catalysts for CO Oxidation

Surface segregation and oxidation of Pt3Ni(1 1 1) alloys under oxygen environment

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