Kinetic Study of Oxygen Reduction Reaction in Acid Solution Using Titanium Oxide-based Catalysts Prepared from Oxy-titanium Tetra-pyrazino-porphyrazine

Hayashi, Tomoaki; Ishihara, Akimitsu; Uehara, Naoki; Kohno, Yuji; Matsuzawa, Koichi; Mitsushima, Shigenori; Ota, Ken Ichiro

doi:10.5796/electrochemistry.83.807

Cited by 6 publications

(2 citation statements)

References 6 publications

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“…The catalysts were synthesized by the thermal decomposition of oxytitanium tetrapyrazinoporphyrazine (TiOTPPz) on multiwalled carbon nanotubes as reported previously. 9,14 In brief, TiOTPPz was mixed with carbon nanotubes, (i) heated up to 900 °C in Ar, (ii) retained at the temperature in Ar containing 2% H 2 and 0.05% O 2 , where equilibrium O 2 partial is 1.3 × 10 −19 atm (retention time = 0, 0.5, 1, 3, 5, and 10 h), and then (iii) cooled down to room temperature. To investigate the contribution of the carbon materials to the catalytic reactions, the samples without oxides were prepared by removing the oxides with hydrofluoric acid.…”

Section: ■ Introductionmentioning

confidence: 99%

Noncrystalline Titanium Oxide Catalysts for Electrochemical Oxygen Reduction Reactions

Tominaka

Ishihara²,

Nagai³

et al. 2017

ACS Omega

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Titanium oxides crystals are widely used in a variety of fields, but little has been reported on the functionalities of noncrystalline intermediates formed in their structural transformation. We measured the oxygen reduction reaction activity of titanium oxide nanoparticles heat-treated for a different time and found that the activity abruptly increased at a certain time of the treatment. We analyzed their structures by using X-ray pair distribution functions with the help of high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy and ascertained that the abrupt increase in the activity corresponded to a structural transformation from a reduced lepidocrocite-type layered titanate to a disordered structure consisting of domains of brookite-like TiO 6 octahedral linkages. The further treatment transformed these brookite-like domains into another phase having more edge-sharing sites like the TiO-type cubic structure. This finding would position noncrystalline, disordered structure as a possible origin of the catalytic activity, though nanocrystalline rutile particles might be also considered as the origin.

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Section: ■ Introductionmentioning

confidence: 99%

Noncrystalline Titanium Oxide Catalysts for Electrochemical Oxygen Reduction Reactions

Tominaka

Ishihara²,

Nagai³

et al. 2017

ACS Omega

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“…Some of the possible alternatives can be catalysts based on transition metal in nitrogen doped graphitic cathodes, [11] oxides and oxynitrides of transition metals e. g. tantalum, [12,13] zirconium oxide based catalysts with multiwalled carbon nanotube (MWCNTs) support [14] and niobium‐titanium complex oxides, [15] among others. Exploring the ORR mechanisms on various catalyst surface, and consequently the active sites, using Density Functional Theory (DFT), helps us gain fundamental understanding regarding the same.…”

Section: Introductionmentioning

confidence: 99%

Bending the ORR Scaling Relations on Zirconium Oxynitride for Enhanced Oxygen Electrocatalysis

2023

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Technologies like polymer electrolyte membrane fuel cells play an important role in environmentally friendly energy conversion. Essential for their commercialization is the development of cheap and efficient electrocatalyst for the oxygen reduction reaction (ORR). Non-platinum group metal (PGM) based catalysts has exhibited favourable activity in acidic electrolytes. In this study, we computationally explore the catalytic sites on the (111) surface of hydrated zirconium oxynitride using periodic DFT calculations. The thermodynamically limiting step is determined to be the O 2 activation step, (O 2 !OOH*) for the majority of the sites, hence strengthening the OOH* intermediate binding will improve ORR activity. The calculations also reveal that the determined scaling relation for G OH -G OOH (DG OOH ¼ 0:78DG OH þ3.52 eV) is comparable to the standard ORR scaling relation (DG OOH ¼ DG OH þ3.2 eV) however G O* -G OH scaling (DG O* ¼ 1:04DG OH þ2.16 eV) deviates dramatically from the typical ORR scaling relation (DG O* ¼ 2DG OH ).

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Tetrapyrazinoporphyrazines and their metal derivatives. Part II: Electronic structure, electrochemical, spectral, photophysical and other application related properties

Novakova

Donzello

Ercolani

et al. 2018

Coordination Chemistry Reviews

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Kinetic Study of Oxygen Reduction Reaction in Acid Solution Using Titanium Oxide-based Catalysts Prepared from Oxy-titanium Tetra-pyrazino-porphyrazine

Cited by 6 publications

References 6 publications

Noncrystalline Titanium Oxide Catalysts for Electrochemical Oxygen Reduction Reactions

Noncrystalline Titanium Oxide Catalysts for Electrochemical Oxygen Reduction Reactions

Bending the ORR Scaling Relations on Zirconium Oxynitride for Enhanced Oxygen Electrocatalysis

Tetrapyrazinoporphyrazines and their metal derivatives. Part II: Electronic structure, electrochemical, spectral, photophysical and other application related properties

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