Ichiro Yamanaka

Avoiding a bang! Electrochemical reduction of O2 in an H2/O2 fuel cell with a three-phase boundary (gaseous O2, aqueous electrolyte, solid cathode) produces concentrated aqueous solutions of H2O2. Even air can serve as the oxygen source.

Direct, safe, and continuous synthesis of neutral H2O2 solutions with concentrations of up to 8 wt % from O2 and water has been accomplished by an improved electrolysis method involving a solid-polymer electrolyte (SPE). The formation and accumulation of neutral H2O2 were strongly enhanced by exposing the cathode to a stream of O2.

An organic hydride system based on hydrogenation/dehydrogenation of toluene (TL)/methylcyclohexane (MCH) has been studied as a hydrogen storage technology. Electrohydrogenation of TL to MCH using a proton exchange membrane (PEM) electrolyzer is proposed as a candidate for the hydrogenation of TL in the organic hydride system. Recently, we reported that a Ketjenblack-supported Ru-Ir alloy (Ru-Ir/KB) cathode was effective for the reaction; however, electrohydrogenation mechanisms and catalyses of

Knallgasfrei und ökonomisch: Die elektrochemische Reduktion von O2 in einer H2/O2-Brennstoffzelle mit Dreiphasen-Grenzfläche (gasförmiges O2, wässrige Elektrolytlösung, feste Kathode) liefert konzentrierte wässrige H2O2-Lösungen. Luft kann bei diesem Verfahren als Sauerstoffquelle dienen.

Die direkte, sichere und kontinuierliche Synthese von neutralen H2O2-Lösungen mit Konzentrationen bis zu 8 Gew.-% aus O2 und Wasser gelingt durch eine verbesserte Elektrolysemethode mit einem festen Polymerelektrolyten (SPE). Die entscheidende Neuerung, die die stark erhöhte Bildung und Anreicherung von H2O2 verursacht, ist ein O2-Strom um die Kathode.

I. Yamanaka, M. Soma and K. Oisuka, J. Chem. Soc., Chem. Commun., 1995, 2235 DOI: 10.1039/C39950002235

Peroxide production: Electrocatalysts of CoCl2(ligand)/XC-72 heat-treated in He at 973 K are examined. N-bidentate ligands of 1,10-phenanthroline and 2,2′-bipyridine are efficient for the formation of neutral H2O2 at 278 K. It is proposed that Co on a bidentate N-coordination site at the carbon surface (CoN2Cx) is the active site for O2 reduction and H2O2 formation.

Peroxide power: Neutral solutions of H2O2 can be produced directly and safely from O2 and H2 by using a fuel cell reaction. The most active and efficient cathode is a vapour-grown carbon fibre (VGCF) electrode coated with Co-tetraphenylporphyrin (0.05 wt %) on VGCF (2 mg cm−2). A maximum concentration of 13.5 wt % (4.0 M) H2O2 is obtained under optimized conditions at 278 K.

The direct dehydrogenative conversion of methane (DCM) to higher hydrocarbons has attracted much attention, because of the efficient utilization of natural gas. Ni catalysis of activation of C–H bonds of methane to H2 and C is well-known. We have tried to control the catalysis of Ni via the addition of second elements and found silica-supported nickel phosphide (Ni–P/SiO2) materials as active catalysts for the DCM reaction at 1173 K. The products included C2H4 (ethylene), C2H6 (ethane), C2H2 (ac

Abstract Catalysts for dehydrogenative conversion of methane (DCM) to higher hydrocarbons are worthy of attention. Indium supported on silica (In/SiO 2 ) was found for effective catalyst for the DCM reaction above 1023 K. Products were ethane, ethylene, acetylene, propylene, benzene, toluene, naphthalene and hydrogen. A highest selectivity of sum of products was 96 % at 1098 K and a steady‐state sum yield was 2.1 % with 63 % selectivity at 1173 K. Characterization studies using temperature‐progr

Direct electro-epoxidation of C 3 H 6 with water was achieved using a solid polymer electrolyte (SPE) electrolysis cell.

The effects of the type of fuel-cell reactors (undivided or divided by cation- and anion-exchange membranes), alkaline electrolytes (LiOH, NaOH, KOH), vapor-grown carbon fiber (VGCF) cathode components (additives: none, activated carbon, Valcan XC72, Black Pearls 2000, Seast-6, and Ketjen Black), and the flow rates of anolyte (0, 1.5, 12 mL h(-1)) and catholyte (0, 12 mL h(-1)) on the formation of hydrogen peroxide were studied. A divided fuel-cell system, O(2) (g)|VGCF-XC72 cathode|2 M NaOH cat

Abstract A higher concentration of H2O2 solution (>1 wt%) was catalytically and directly synthesized from O2 and H2 over a [active carbon+vapor-grown-carbon-fiber] cathode by a new type of fuel cell system at 1 atm.