A5022281104- Electrochemical Analysis and Applications
- Electrocatalysts for Energy Conversion
- Molecular Junctions and Nanostructures
- Fuel Cells and Related Materials
- Advanced Chemical Physics Studies
- Surface and Thin Film Phenomena
- Surface Chemistry and Catalysis
- X-ray Diffraction in Crystallography
- Analytical Chemistry and Sensors
- Catalytic Processes in Materials Science
- Crystallization and Solubility Studies
- Electron and X-Ray Spectroscopy Techniques
- Crystallography and molecular interactions
- Gas Sensing Nanomaterials and Sensors
- Graphene research and applications
- Spectroscopy and Quantum Chemical Studies
- Advanced Materials Characterization Techniques
- Magnetic and transport properties of perovskites and related materials
- Force Microscopy Techniques and Applications
- nanoparticles nucleation surface interactions
- Semiconductor materials and devices
- Conducting polymers and applications
- Advanced battery technologies research
- Electronic and Structural Properties of Oxides
- Electrochemical sensors and biosensors
Chiba University
2015-2024
Sekisui Chemical (Japan)
2023
Tokyo Institute of Technology
2020-2023
Kyoto University
2000-2023
Tokushima University
2017-2018
Tohoku University
1995-2018
Hitachi (Japan)
1991-2018
Ibaraki National College of Technology
2018
Hoshi University
2018
Ebara (Japan)
2018
Structural effects on the rates of formic acid oxidation have been studied Pd(111), Pd(100), Pd(110), and Pd(S)-[n(100)×(111)] (n = 2−9) electrodes in 0.1 M HClO4 containing with use voltammetry. On low index planes Pd, maximum current density (jP) increases positive scan as follows: Pd(110) < Pd(111) Pd(100). This order differs from that Pt: Pt(111) Pt(100) Pt(110). terrace atomic rows n ≥ 3 almost same jP except Pd(911) 5. The value 5 is 20% higher than those other surfaces. Pd(311) 2,...
Active sites for the oxygen reduction reaction (ORR) have been studied on low index planes, n(100)-(111) and n(100)-(110) series of Pd with use hanging meniscus rotating disk electrode (RDE) in 0.1 M HClO4 saturated O2. The Kotekey−Levich plots give a linear line slope about 4, showing four electron ORR electrodes, as is case Pt. Activity ORR, which estimated by current density at 0.90 V (RHE) jORR,0.90V, gives following order planes: Pd(110) < Pd(111) Pd(100). This completely opposite to...
The basal plane of graphene has been known to be less reactive than the edges, but some studies observed vacancies in after reaction with oxygen gas. Observation these typically limited nanometer-scale resolution using microscopic techniques. This work demonstrates introduction and observation subnanometer by heat treatment a flow gas at low temperature such as 533 K or lower. High-resolution transmission electron microscopy was used directly observe vacancy structures, which were compared...
Highly active catalysts for the oxygen reduction reaction are essential widespread and economically viable use of polymer electrolyte fuel cells. Here we report activities single‒crystal platinum electrodes in acidic solutions containing tetraalkylammonium cations with different alkyl chain lengths. The high hydrophobicity a cation longer enhances activity. activity on Pt(111) presence tetra‒n‒hexylammonium is eight times as that without this cation, which comparable to Pt3Co(111) Pt3Ni(111)...
Lattice strain of Pt-based catalysts reflecting d-band status is the decisive factor their catalytic activity toward oxygen reduction reaction (ORR). For newly arisen monolayer Pt system, however, no general strategy to isolate lattice has been achieved due short-range ordering structure shells on different facets core nanoparticles. Herein, based extended X-ray absorption fine atoms various single crystal facets, we propose an effective methodology for evaluating The quantitative...
Abstract Enhancing the activity of oxygen reduction reaction (ORR) is crucial for fuel cell development, and hydrophobic species are known to increase ORR activity. This paper reports that caffeine enhanced specific Pt(111) 11-fold compared without in a 0.1 M HClO 4 aqueous solution. Moreover, increased Pt(110) 2.5-fold; however, Pt(100) was unaffected. The infrared (IR) band PtOH (blocking ORR) decreased all surfaces. Caffeine adsorbed with its molecular plane perpendicular surfaces tilted...
The surface oxidation states of the metal electrodes affect activity, selectivity, and stability electrocatalysts. Oxide formation reduction on such must be comprehensively understood to achieve next-generation electrocatalysts with outstanding performance stability. Herein, initial electrochemical Pt(111) in alkaline media containing hydrophilic hydrophobic cations is investigated by X-ray crystal truncation rod (CTR) scattering, infrared (IR) spectroscopy, nanoparticle-based...
The main components of a new beamline for surface and interface crystal structure determination at SPring-8 are briefly described. Stages the monochromator modified making an incident X-ray intensity more stable experiments. Absolute photon flux densities were measured with energy. A ultrahigh vacuum system is introduced preliminary measurements from ordered oxygen on Pt (111) surface.
Electrical double layer: The detailed outer Helmholtz plane (HP) structure composed of Cs+ above c(2×2)-Br on Ag(100) electrode using in situ surface X-ray diffraction electrochemical environments is described. Hydrated cations are accommodated the hollow sites layer. coverage and distance layer from depend potential. A single water intercalated between inner HP ions (see picture).
A perovskite single-crystal substrate, NdGaO3 (001), was thermally annealed in air to give an atomically defined surface structure. From analysis with coaxial impact-collision ion scattering spectroscopy, the terminating atomic layer identified be NdO1+δ , i.e., A-site oxide monolayer ABO3. This result is contrary B-site (BO2−δ) termination observed other surfaces, such as wet etched SrTiO3 and LaAlO3 or (LaAlO3)0.3–(Sr2AlTaO6)0.7 (LSAT).
Abstract The oxidation processes of a Pt(111) electrode in alkaline electrolytes depend on non‐specifically adsorbed ions according to situ X‐ray diffraction and infrared spectroscopic measurements. In an aqueous solution LiOH, OH ad adlayer is formed the first step as result strong interaction between Li + , whereas Pt proceeds without formation CsOH solution. Structural analysis by indicates that strongly protective against surface roughening caused subsurface oxidation. Although Cs...
In situ vibrational spectra of Pt oxides that cannot be measured with IR spectroscopy have been studied on the low index planes using surface enhanced Raman bare Au nanoparticles (NPSERS). Two bands appear around 570 and 340 cm-1 at higher potentials in 0.1 M HClO4 saturated Ar, which are assigned to stretching vibration Pt-O(H) libration Pt-O, respectively. NPSERS O2 solution for first time. The band intensities Pt-O significantly compared those Ar solution. onset formation 1.15 V(RHE)...
Weakening of the poisoning by specifically adsorbed anions assists in developing next-generation electrocatalysts for use low-temperature fuel cells. In this study, we evaluated how hydrophobic cations with different alkyl chain lengths affect oxygen reduction reaction (ORR) activities on single-crystal Pt surfaces contact sulfuric acid solution and Nafion ionomers. Interfacial tetraalkylammonium longer chains activated ORR Pt(111) surface. a containing tetrahexylammonium (THA+),...
Defect structures in carbon materials have attracted much attention recent years since the introduction of defects such as 5- and 7-membered rings, edges, functional groups improves performance various applications. In particular, rings are one most stable because exist basal plane materials. However, there been no reports catalyst-free synthesis with high percentages rings. this study, a percentage was conducted by simple bromination heat treatment azulene (Azu) composed only Compared to...
Carbon-based materials are regarded as an environmentally benign alternative to the conventional metal electrode used in electrochemistry from viewpoint of sustainable chemistry. Among various carbon materials, boron-doped diamond (BDD) exhibits superior electrochemical properties. However, it is still uncertain how surface chemical species BDD influence performance, because difficulty characterizing species. Here, we have developed situ spectroscopic measurement systems on electrodes, i.e.,...