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Smith, J. R.; Walsh, Frank C.; Clarke, Robert L.

doi:10.1023/a:1003469427858

Cited by 305 publications

(165 citation statements)

References 25 publications

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“…It is known that rutile (TiO 2 ) can be doped with other cations to prepare Ti 1−x M x O 2 , where M = Zr, Hf, V, Nb, Ta, Cr, Mo, W, Ru, Os, Ir and Sn, and some of these oxides have been evaluated in electrochemical environments (Chang 1968;Sakata et al 1969;Horkans & Shafer 1977;Pejryd 1986;Smith et al 1998;Murata et al 2000;Roy et al 2000;Chen et al 2003;Colomer & Velasco 2007;Garcia et al 2007;Sasaki et al 2008). In this paper, we discuss the preparation and properties of W-doped TiO 2 (rutile phase: Ti 1−x W x O 2 ) and explore the preparation and use of 50 nm nanoparticles suitable for catalyst supports.…”

confidence: 99%

Catalyst supports for polymer electrolyte fuel cells

Subban

Zhou

Leonard

et al. 2010

Phil. Trans. R. Soc. A.

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A major challenge in obtaining long-term durability in fuel cells is to discover catalyst supports that do not corrode, or corrode much more slowly than the current carbon blacks used in today's polymer electrolyte membrane fuel cells. Such materials must be sufficiently stable at low pH (acidic conditions) and high potential, in contact with the polymer membrane and under exposure to hydrogen gas and oxygen at temperatures up to perhaps 120• C. Here, we report the initial discovery of a promising class of doped oxide materials for this purpose: Ti 1−x M x O 2 , where M = a variety of transition metals. Specifically, we show that Ti 0.7 W 0.3 O 2 is electrochemically inert over the appropriate potential range. Although the process is not yet optimized, when Pt nanoparticles are deposited on this oxide, electrochemical experiments show that hydrogen is oxidized and oxygen reduced at rates comparable to those seen using a commercial Pt on carbon black support.

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confidence: 99%

Catalyst supports for polymer electrolyte fuel cells

Subban

Zhou

Leonard

et al. 2010

Phil. Trans. R. Soc. A.

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“…These substoichiometric phases have been widely observed in TiO 2 thin films [11], nanoparticles [21] and nanowires [22]. Due to the metallic conductivity, they have been widely considered as possible electrode materials in batteries and fuel cells [23][24][25]. The desirable chemical stability and abundant low-temperature behaviors of Magnéli phases also generated substantial research interests lately [26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Polaronic interactions between oxygen vacancies in rutile TiO2

2017

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Oxygen vacancy-vacancy interactions in rutile TiO 2 are studied in conjunction with polaron formation trends using density functional theory calculations. It is found that polarons strongly enhance the formation of oxygen vacancies in this material, and also mediate the interactions between existing vacancies. At distances below one nanometer, two isolated and charge-neutral vacancies exhibit attractive interactions with an equilibrium distance of about 4 Ångstroms. The attractive forces between vacancies partly arise from the polaronic transfer of excess electrons to reduce the potential energy. These discoveries provide microscopic explanations to the vacancy clustering phenomena, as well as a practical approach to stabilize the polarons at arbitrary Ti atoms in TiO 2 .

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“…In many cases the effects are poorly understood. There are also particular technological applications that exploit the substoichiometry such as electrochemistry 20 and tribology. 21 The defective nature of the oxide has profound consequences for the structure and electronic structure that are revealed, in part, by electronic measurements.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamics of oxygen defective Magnéli phases in rutile: A first-principles study

2008

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Ab initio thermodynamics has been used to calculate the formation energies, in different environmental conditions, for a number of oxygen-defective structures in rutile. In addition to the Ti n O 2n−1 ͑3 ഛ n ഛ 5͒ Magnéli phases, the two fundamental points defects, Ti interstitials and neutral oxygen vacancies, were also considered. The predicted phase stability is compared to available experimental data and there is reasonable agreement between the calculated phase boundaries and those observed. These results are used to discuss a mechanism that has been proposed as an explanation for the formation of the crystallographic shear planes in rutile.

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Untitled

Cited by 305 publications

References 25 publications

Catalyst supports for polymer electrolyte fuel cells

Catalyst supports for polymer electrolyte fuel cells

Polaronic interactions between oxygen vacancies in rutile TiO2

Thermodynamics of oxygen defective Magnéli phases in rutile: A first-principles study

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