Shougo Higashi

• Toyota Central R & D Labs., Inc.

Large-scale deployment of polymer electrolyte membrane water electrolysis, which is a promising technology for green hydrogen production, requires significant reduction of Ir in catalyst layer due to its high material cost. However, as the Ir amount in the catalyst layer decreases, number of electrically-isolated-inactive catalysts increases, resul...

Solar steam generation is an attractive method to produce clean water, and high steam generation rates have been achieved using nanostructured light absorbers. However, since it usually takes minutes to reach the temperature for steady-state steam generation under solar illumination, a material that responds quickly to intermittent sunlight is stro...

Hydrous ruthenium oxide (RuO2) nanoparticles are hybridized inside the pores of activated carbon (AC) for preparing electrochemical capacitor electrodes. The hybridization consists of the adsorption of an organoruthenium complex and subsequent heat treatment to reduce the complex into Ru nanoparticles within the AC pores, followed by the electroche...

Nanocatalysts have high surface area-to-volume ratios, which are beneficial for minimizing material usage and achieving high catalytic activity. However, preparing a catalyst layer that consists of nanoparticles, involves several costly steps and requires a well-controlled and safe production line. Herein, we report the fabrication of a free-standi...

Electrospinning is a widely used production method for nanoscale fine polymer fiber fabrics. An ultrafine fiber made of polymers such as polyvinylpyrrolidone (PVP) polyacrylic acid (PAA) has immense potential for applications in air filters, batteries, and biosensors. However, producing fabrics with long uniformly distributed ultrafine fibers of a...

IrO2 is a state-of-the-art catalyst that can be used in acidic conditions and has potential for application as an oxygen evolution reaction (OER) catalyst in proton exchange membrane electrolyzers. IrO2 is subjected to heat treatment at the synthesis and at the preparation of the catalyst layer, and fundamental studies regarding the synthesis condi...

Platinum nanocatalysts play critical roles in CO oxidation, an important catalytic conversion process. As the catalyst size decreases, the influence of the support material on catalysis increases which can alter the chemical states of Pt atoms in contact with the support. Herein, we demonstrate that under-coordinated Pt atoms at the edges of the fi...

Ir nanoparticles are finely dispersed over whole particles of activated carbon (AC) via the gas phase adsorption of an organoiridium complex in the AC and subsequent heat treatment. Structural analysis...

CO oxidation is an important primary reaction in automotive catalysis, and has been studied extensively since the 1970s because of its fundamental nature and technological relevance to emission control regulations. In this Review, we investigate the development of state-of-the-art catalysts for CO oxidation and consider the important achievements i...

In article number 1601052, Yi Cui, Jaephil Cho, and co-workers report a facile and scalable strategy for synthesizing electrocatalysts for metal-air batteries. The obtained catalysts exhibit better performances in a Zn-air single cell at high current densities than a Pt/C electrode. The cover image shows the composites of the N-doped carbon sheets...

To date, most studies have focused only on the interaction between oxygen and the catalyst, with the intention of minimizing the mass-transfer resistance by using the rotating disk electrode (RDE) method, which is based on the forced-convection theory. To begin with, in order to increase the reaction rate, the oxygen should be able to reach the act...

Portable power sources and grid-scale storage both require batteries combining high energy density and low cost. Zinc metal battery systems are attractive due to the low cost of zinc and its high charge-storage capacity. However, under repeated plating and stripping, zinc metal anodes undergo a well-known problem, zinc dendrite formation, causing i...

Supplementary Figures 1 - 7

A magnesium battery 10 according to the present invention includes a positive electrode 12, a negative electrode 14 having a magnesium-containing negative electrode active material, and an inorganic magnesium solid electrolyte 16 that is interposed between the positive electrode 12 and the negative electrode 14, has a complex ion structure that con...

The conduction of the bivalent magnesium cation, Mg(2+), in an inorganic solid state material, Mg(BH4)(NH2), has been demonstrated. This material exhibited a high ionic conductivity of 10(-6) S cm(-1) at 150 °C, and its electrochemical window was estimated to be approximately 3 V using cyclic voltammetry.

Ionic liquids composed of N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium (DEME), N-methyl-N-methoxyethylpiperidinium (PP1.1o2) cations functionalized with ethers, N-methyl-N-propylpiperidinium (PP13), and N-butyl-N-methylpyrrolidinium (P14) cations and the bis(trifluoromethanesulfonyl) amide (TFSA) anion are investigated for application as electro...

Li-air battery using ionic liquids, N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis (trifluoromethylsulfonyl) amide (DEME-TFSA) and N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)amide (PP13-TFSA), as the solvents for electrolyte have been studied. A significant improvement of discharge capacity has been observed for DEME-TFSA (431...

High oxygen radical stability of electrolyte solvent is a key parameter necessary to overcome a large voltage gap in discharge–charge profiles of the non-aqueous Li–air battery. We have proposed N-methyl-N-propylpiperidinium bis(trifluoromethansulfonyl)amide (PP13TFSA) as an appropriate candidate of the electrolyte solvent. PP13TFSA based Li–O2 cel...

The addition of potassium superoxide (KO2) into the electrolyte for Li-air battery was proved to be an effective screening method to examine the stability of the solvents against superoxide anion radicals (O2•−). It was also confirmed that the coupled compound between Li+ and O2•−, namely LiO2•, was highly reactive for many solvents to decompose th...

Manganese (Mn) adsorption on the Si(111)-(7×7) surface followed by annealing at a relatively low temperature of 250 °C has been studied by using scanning tunneling microscopy as well as low-energy electron diffraction and Auger-electron spectroscopy. The B20-type structure of a Mn monosilicide (MnSi) of epitaxial ultrathin films is formed with a (√...

The adsorption of calcium (Ca) atoms on a Cu(001) surface has been studied by low-energy electron diffraction (LEED) at 130, 300 and 400K. It is found that a (4×4) was the only LEED pattern appeared at 400K while a quasi-hexagonal structure was formed in a wide range of submonolayer coverage at 130K. At 300K, the (4×4) LEED spots were broad and wea...

Thin MnSi films growing by units of a quadruple layer of a B20-type structure are observed on the Si(111) surface by scanning tunneling microscopy. Based on the observation, a model of growth controlled by an interplay between MnSi crystal growth and supply of Si atoms from substrate is proposed. A simple Monte Carlo model efficiently simulating si...

Flat MnSi ultrathin films are epitaxially grown on the Si(111)-(7×7) surface by Mn deposition and subsequent annealing. Low-energy electron diffraction exhbits the brightest (×)R30° patterns when Mn atoms are deposited at ∼ 3 ML with subsequent annealing at 250 °C. Scanning tunneling microscopy shows that atomically flat MnSi(111) surfaces with the...

We report on the re-determination of the structure of p(2×2)Sb/Cu(001) from measured LEED I/V data. The structure solution is performed in two steps. First an approximate “image” of the surface structure model is found by an application to the measured data of the recently-proposed Phase and Amplitude Recovery and Diffraction Image Generation Metho...

We have studied the individual adsorption of Mn and Bi, and their coadsorption on Cu(001) by low-energy electron diffraction (LEED). For Mn, we have determined the c(2×2) structure formed at 300K, whose structure had been determined by several methods. We reconfirmed by a tensor LEED analysis that it is a substitutional structure and that a previou...

Two coadsorption systems of Bi + Mg and Sb + Mg on Cu(0 0 1) have been studied by means of low-energy electron diffraction (LEED). A (4 × 4) LEED pattern with glide planes was observed in either case at ˜400 K. The two (4 × 4) structures were determined by a tensor LEED analysis. Both (4 × 4) structures are equivalent, and consist of a grid network...