A5083848806- Electrocatalysts for Energy Conversion
- Fuel Cells and Related Materials
- Electrochemical Analysis and Applications
- Advanced battery technologies research
- GaN-based semiconductor devices and materials
- Machine Learning in Materials Science
- Medical Imaging Techniques and Applications
- Catalytic Processes in Materials Science
- Semiconductor materials and devices
- Electron and X-Ray Spectroscopy Techniques
- ZnO doping and properties
- Advancements in Solid Oxide Fuel Cells
- Semiconductor Quantum Structures and Devices
- Radiomics and Machine Learning in Medical Imaging
- Metal and Thin Film Mechanics
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Catalysis and Oxidation Reactions
- Advanced MRI Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Ga2O3 and related materials
- Lung Cancer Treatments and Mutations
- Cancer, Hypoxia, and Metabolism
- Metal-Organic Frameworks: Synthesis and Applications
- Atomic and Subatomic Physics Research
Japan Synchrotron Radiation Research Institute
2021-2025
University of Electro-Communications
2014-2024
SPring-8
2021-2024
Innovation Research Center
2024
The University of Tokyo
2006-2023
JEOL (Japan)
2023
Osaka University
2008-2018
Osaka Research Institute of Industrial Science and Technology
2012
Toyohashi University of Technology
2008
Kanazawa Medical University
1992-2007
Hexavalent iridium (Ir
To prospectively evaluate diffusion-weighted (DW) magnetic resonance (MR) imaging with a split acquisition of fast spin-echo signals for diffusion (SPLICE) sequence tissue characterization lung carcinomas by using apparent coefficients (ADCs).An institutional review board approved this study; informed consent was obtained from patients. Thirty patients (nine women, 21 men; mean age, 68.0 years) carcinoma underwent DW MR the SPLICE sequence. ADC each calculated images low and high b values....
Magnetic and transport properties are investigated for single crystals of layered perovskite cobalt oxides, ${\mathrm{La}}_{2\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Sr}}_{\mathrm{x}}$${\mathrm{CoO}}_{4}$ (0.4\ensuremath{\leqslant}x\ensuremath{\leqslant}1.0). The effective magnetic moment ${\mathrm{\ensuremath{\mu}}}_{\mathrm{eff}}$ is found to decrease with increasing x (or the number ${\mathrm{Co}}^{3+}$ ions) from \ensuremath{\approx}4.0${\mathrm{\ensuremath{\mu}}}_{\mathrm{B}}$...
Simultaneous improvements in oxygen reduction reaction (ORR) activity and long-term durability of Pt-based cathode catalysts are indispensable for the development next-generation polymer electrolyte fuel cells but still a major dilemma. We present robust octahedral core–shell PtNix/C electrocatalyst with high ORR performance (mass surface specific 6.8–16.9 20.3–24.0 times larger than those Pt/C, respectively) (negligible loss after 10000 accelerated test (ADT) cycles). The key factors...
Abstract The three‐dimensional (3D) distribution and oxidation state of a Pt cathode catalyst in practical membrane electrode assembly (MEA) were visualized polymer electrolyte fuel cell (PEFC) under fuel‐cell operating conditions. Operando 3D computed‐tomography imaging with X‐ray absorption near edge structure (XANES) spectroscopy (CT‐XANES) clearly revealed the heterogeneous migration degradation an MEA during accelerated test (ADT) PEFC. degradative proceeded over entire layer spread to...
Single-atom catalysts are a relatively new type of catalyst active for numerous reactions but mainly chemical transformations performed at low or intermediate temperatures. Here we report that singly dispersed Rh1O5 clusters on TiO2 can catalyze the partial oxidation methane (POM) high temperatures with selectivity 97% producing syngas (CO + H2) and activity long catalytic durability 650 °C. The results from substitution Ti atom surface lattice by Rh1, which forms Rh1 coordinating five...
We have achieved significant improvements for the oxygen reduction reaction activity and durability with new SnO2-nanoislands/Pt3Co/C catalysts in 0.1 M HClO4, which were regulated by a strategic fabrication using selective electrochemical Sn deposition method. The nano-SnO2/Pt3Co/C Pt/Sn = 4/1, 9/1, 11/1, 15/1 characterized STEM-EDS, XRD, XRF, XPS, situ XAFS, measurements to Pt3Co core/Pt skeleton-skin structure decorated SnO2 nanoislands at compressive Pt surface defects dislocations. high...
Herein, we demonstrated that carbon-supported platinum (Pt/C) is a low-cost and high-performance electrocatalyst for polymer electrolyte fuel cells (PEFCs). The ethanol reduction method was used to prepare the Pt/C catalyst, which realized by an effective matching of carbon support optimization Pt content preparing membrane electrode assembly (MEA). For this, synthesis catalysts with different loadings performed on two carbons (KB1600 KB800) as new materials. Analysis XRD pattern TEM images...
The dynamics of Pt/CeO 2 during catalysis for CO oxidation were revealed by high-energy resolution fluorescence-detected (HERFD) Pt L 3 -edge X-ray absorption near-edge structure (XANES) spectroscopy with millisecond time resolution.
To determine the biochemical characteristics of lung cancer tissue using in vitro (1)H-MRS, and investigate correlation between survival probabilities lactate (Lac), creatine (Cr), choline (Cho) concentrations measured by (1)H-MRS.A total 21 patients with were included this retrospective study. (1)H-MRS spectra measurements performed at 6.35T a JNM-EX270, high-resolution FT-NMR spectrometer.When normal was compared tissue, significant differences noted most consistently levels Lac Cho,...
The electrochemical activity and durability of Pt nanoparticles on different kinds carbon supports in oxygen reduction reactions (ORR) were investigated using rotating disc electrodes (RDE) the membrane electrode assemblies (MEA) polymer electrolyte fuel cells (PEFC). mass Pt/C catalysts (ORR per 1 mg Pt) at RDE decreased, according to type support, following order; Ketjenblack (KB) > acetylene black (AB) graphene multiwall nanotube (MW-CNT) (CB), whereas average size surface specific area)...
We have succeeded in simultaneous operando time-resolved quick X-ray absorption fine structure (QXAFS)–X-ray diffraction (XRD) measurements at each acquisition time of 20 ms for a Pt/C cathode catalyst polymer electrolyte fuel cell (PEFC), while measuring the current/charge PEFC during transient voltage cyclic processes (0.4 VRHE → 1.4 0.4 VRHE) under H2(anode)–N2(cathode). The rate constants Pt–O bond formation/dissociation, Pt charging/discharging, Pt–Pt dissociation/reformation, and...
Abstract There is limited information on the mechanism for platinum oxidation and dissolution in Pt/C cathode catalyst layers of polymer electrolyte fuel cells (PEFCs) under operating conditions though these issues should be uncovered development next‐generation PEFCs. Pt species are mapped by a XAFS (X‐ray absorption fine structure) method quick‐XAFS(QXAFS) method. Information site‐preferential leaching nanoparticles around boundary micro‐crack degraded PEFCs provided, which relevant to...
Catalyst degradation at the cathode of a membrane electrode assembly (MEA) remains critical issue for practical polymer electrolyte fuel cell (PEFC) operation, but such wet systems impede detailed visualization events in during its operation. In this work, first time, operando spectroimaging (X-ray absorption near-edge structure–computed tomography) was used to produce clear three-dimensional (3D) images morphology, Pt and Co distributions, Co/Pt atomic ratio, valence state Pt–Co/C catalyst...
We have made the first success in same-view imagings of 2D nano-XAFS and TEM/STEM-EDS under a humid N2 atmosphere for Pt/C cathode catalyst layers membrane electrode assemblies (MEAs) polymer electrolyte fuel cells (PEFCs) with Nafion to examine degradation cathodes by anode gas exchange cycles (start-up/shut-down simulations PEFC vehicles). The imaging provided unprecedented spatial information on distribution Pt nanoparticles oxidation states layer as well ionomer-filled nanoholes carbon...
It is hard to directly visualize spectroscopic and atomic-nanoscopic information on the degraded Pt/C cathode layer inside polymer electrolyte fuel cell (PEFC). However, it mandatory understand preferential area, sequence, relationship of degradations Pt nanoparticles carbon support in by observing catalyst for development next-generation PEFC catalysts. Here, spectroscopic, chemical, morphological visualization degradation electrocatalysts was performed successfully a same-view combination...
Transient-response kinetics of the transformations (six elementary steps) Pt valence, coordination number Pt–Pt bonds, and Pt–O bonds a Pt/C cathode catalyst in polymer electrolyte fuel cell (PEFC) under cyclic voltage operations (0.4 → 1.4 0.4 VRHE) during anode–gas exchange (AGEX) treatments (start-up/shut-down) has been studied by situ time-resolved quick X-ray absorption fine structure (QXAFS, 100 ms/spectrum). The transient-response analysis identified existence fractions three...
There is little information on the spatial distribution, migration, and valence of Ce species doped as an efficient radical scavenger in a practical polymer electrolyte fuel cell (PEFC) for commercial vehicles (FCVs) closely related to severe reliability issue long-term PEFC operation. An situ three-dimensional fluorescence computed tomography-X-ray absorption fine structure (CT-XAFS) imaging technique same-view nano-XAFS-scanning electron microscopy (SEM)/energy-dispersive spectrometry...
We present evidence for long-range interfacial geometric interactions at metal–support interfaces by a combination of atomic scale and <italic>in situ</italic> characterizations.