A5024625913- Electrocatalysts for Energy Conversion
- Fuel Cells and Related Materials
- Electrochemical Analysis and Applications
- Advanced battery technologies research
- Conducting polymers and applications
- Catalytic Processes in Materials Science
- Molecular Junctions and Nanostructures
- Machine Learning in Materials Science
- Semiconductor materials and devices
- Spectroscopy and Quantum Chemical Studies
- Catalysis and Hydrodesulfurization Studies
- Advanced Memory and Neural Computing
- Electrostatics and Colloid Interactions
- Advancements in Solid Oxide Fuel Cells
- Supercapacitor Materials and Fabrication
- Atomic and Molecular Physics
- Fault Detection and Control Systems
- Spectroscopy and Laser Applications
- Advanced Battery Materials and Technologies
- Nuclear Materials and Properties
- Advanced Battery Technologies Research
- Transition Metal Oxide Nanomaterials
- nanoparticles nucleation surface interactions
- Analytical Chemistry and Sensors
- Water Quality Monitoring and Analysis
Toyota Central Research and Development Laboratories (Japan)
2016-2025
Toyota Motor Corporation (Switzerland)
2012-2025
Argonne National Laboratory
2009-2015
National Institute of Technology, Toyota College
2009-2010
Tokyo Institute of Technology
2004
The effect of side-chain structures in perfluoro-sulfonic acid ionomers on the adsorption terminal sulfonate moiety surface Pt is investigated with voltammetry and surface-enhanced infrared absorption spectroscopy (SEIRAS). Analyses low-molecular-weight model anions without an ether group perfluoro-alkyl chain indicate that are adsorbed through one or two oxygen atom(s) atom also interacts surface, leading to stronger group. On basis results obtained anions, moieties perfluorinated sulfonic...
In recent years, considerable research and development efforts are devoted to improving the performance of polymer electrolyte fuel cells. However, power density catalytic activities these energy conversion devices still far from being satisfactory for large-scale operation. Here we report enhancement via incorporation, in cathode catalyst layers, a ring-structured backbone matrix into ionomers. Electrochemical characterizations single cells microelectrodes reveal that high is obtained using...
The aim of this study was to clarify the effectiveness and challenges applying mesoporous tin oxide (SnO2)-based supports for Pt catalysts in cathodes polymer electrolyte fuel cells (PEFCs) simultaneously achieve high performance durability. Recently, focus PEFC application automobiles has shifted heavy-duty vehicles (HDVs), which require durability, energy-conversion efficiency, power density. It been reported that employing carbon improves initial by mitigating catalyst poisoning caused...
This Letter reveals new findings on the influence of noncovalent interactions electrochemical interface. Using surface X-ray scattering, we demonstrate that barium cations are located at 3.4 Å away from surface, suggesting they partially hydrated, though not adsorbed surface. The effect cation oxygen reduction reaction (ORR) ranges significant (Pt) to little (Au), depending nature metal and cation. Finally, show these results, as obtained well-defined single-crystal surfaces, correlate well...
The catalyst poisoning property of a novel ionomer, NBC4, which has two sulfonimide acid groups in its side chain ended with perfluorobutane, instead sulfonic as Nafion does, was theoretically and experimentally compared that Nafion. A density functional theory combined continuum electrolyte showed the adsorption is weaker for anion than sulfonate on Pt (111) surface. Electrochemical measurements using surfaced single crystal electrodes covered ionomer films higher ORR activity by ca. 50% at...
A first principles-based mean field model was developed for the oxygen reduction reaction (ORR) taking account of coverage- and material-dependent reversible potentials elementary steps. This applied to simulation single crystal surfaces Pt, Pt alloy core-shell catalysts under Ar O(2) atmospheres. The results are consistent with those shown by past experimental theoretical studies on surface coverages atmosphere, shape current-voltage curve ORR Pt(111) material-dependence activity. suggests...
The purpose of this study is to test the concept protecting vulnerable sites on cathode catalysts in polymer electrolyte fuel cells. Pt single-crystal surfaces were modified by depositing Au atoms selectively (100) step and their electrocatalytic activities for oxygen reduction reaction (ORR) stabilities against potential cycles examined. ORR raised 70% modifications, rise activity was ascribed enhanced local Pt(111) terraces surface atoms. modifications also stabilized low-coordinated from...
Pt nanoparticles supported on carbons (Pt/C) as the cathode catalyst for polymer electrolyte fuel cells (PEFCs) were modified with dopamine (DA) and heat-treated, their performance durability investigated to test concept of forming carbon thin layers surfaces. The coverage adsorbed sulfonates from ionomer surfaces was decreased increasing addition amount DA, a consequence, mass activity improved. In addition, retention electrochemical surface area cell after improved DA amount. in high...
Abstract Ionomers are used in polymer electrolyte fuel cells (PEFCs) catalyst layers to improve proton conduction. Recent analytical studies have clarified that the adsorption of ionomer on surface a Pt deteriorates catalytic activity for oxygen reduction reaction and transport properties near surface. These findings led development new materials, such as mesoporous carbon support highly oxygen-permeable ionomer, which now commercially used. In this review article, we summarize recent...
Abstract The search for more durable supports oxygen reduction reaction (ORR) catalyst is a topic of increasing importance in the development polymer electrolyte fuel cells (PEFCs). Recently, tin oxide (SnO2) have garnered attention because their high oxidative stability. However, improving cell performance, particularly under wet conditions, remains challenge before successful deployment. Herein, we expand on our previous work carbon-free mesoporous SnO2-based and investigate effects...
Density functional theory calculations were applied to OH formations on stepped Pt electrodes of Pt[n(111) × (111)] (n = 3, 4, and 6) for examining solvation effects the adsorbates. Results indicated that adsorbates at terrace sites are slightly destabilized by water molecules adsorbed step forming 1-dimensional chains whereas significantly 2-dimensional honeycomb structures. On surfaces with narrow widths, cannot exist sites, therefore, disappear. Hence, formed a low potential region, ca....
A mean field kinetic model was developed for electrochemical oxidations and reductions of Pt(111) on the basis density functional theory calculations, reaction mechanisms were analyzed. The reasonably describes asymmetric shapes cyclic voltammograms small Tafel slopes relevant redox reactions observed in experiments without assuming any unphysical forms rate equations. Simulations using indicate that oxidation proceeds via an from Pt to PtOH a disproportionation PtO Pt, while its reduction two Pt.
Abstract The adsorption of the perfluoro‐sulfonic acid polymer Nafion and ionic liquid (IL) 1‐butyl‐3‐methylimidazolium bis(trifluoromethanesulfonyl)imide on surface Pt was investigated via voltammetric analyses, using stepped single‐crystal electrodes with (111) terraces (110) steps, surface‐enhanced infrared absorption spectroscopy (SEIRAS) analyses a polycrystalline electrode. Sulfonate anion in adsorbed suppressed oxygen reduction reaction (ORR) activity by more than 50%, regardless...