Tetsuya Uda

Solid-acid fuel cells (SCFCs) utilize an anhydrous, nonpolymeric proton conducting electrolyte that can operate at slightly elevated temperatures. By supporting thin CsH2PO4 electrolyte membranes (25-36 µm), on porous stainless steel gas-diffusion electrodes, SAFCs with peak power densities as high as 415 mW/cm^2 were obtained. Cells were operated at ~240°C with humidified H2 supplied to the anode and humidified O2 supplied to the cathode. Despite the thinness of the membranes, the open-circuit

A process is demonstrated for the efficient separation of rare earth elements, using a combination of selective reduction and vacuum distillation of halides. The large differences in the redox chemistry of the rare earth elements and in the vapor pressures of rare earth di- and trihalides are exploited for separation. Experimental proof of concept is provided for the binary systems praseodymium-neodymium and neodymium-samarium. This process enhances the separation factor for the isolation of sam

A large amount of neodymium magnet sludge is generated during the manufacture process. Because the sludge is considerably contaminated by oxygen, it is difficult to reuse it as it is. The present basic study has been carried out to establish efficient recycling process of the sludge. The rare earths in the neodymium magnet sludge were extracted by chlorination with FeCl2. An activated carbon was used as a de-oxidation reagent. Metallic iron in the sludge was not chlorinated because the iron mono

The dehydration behavior of caesium dihydrogen phosphate CsH2PO4 was investigated in the temperature range of 230 °C to 260 °C under high humidity, conditions of particular relevance to the operation of fuel cells based on this electrolyte. The onset temperature of dehydration was determined from changes in ionic conductivity on heating and confirmed by weight change measurements under isothermal conditions. The relationship between the onset temperature of dehydration (Tdehy) and water partial

Knowledge of thermal behavior of electrolyte is important for fuel cell fabrication. In this study, using high‐temperature X ‐ray diffraction analysis ( HT ‐ XRD ) and thermo‐mechanical analysis ( TMA ), a systematic investigation of lattice constants was performed on Y‐doped BaZrO 3 , which is a promising candidate for electrolyte in protonic ceramic fuel cells. The results revealed that a chemical expansion was observed between 300°C and 450°C during the heating process in HT ‐ XRD , and was a

High-power-density alcohol fuel cells can relieve many of the daunting challenges facing a hydrogen energy economy. Here, such fuel cells are achieved using CsH 2 PO 4 as the electrolyte and integrating into the anode chamber a Cu-ZnO/Al 2 O 3 methanol steam-reforming catalyst. The temperature of operation, 250C, is matched both to the optimal value for fuel cell power output and for reforming. Peak power densities using methanol and ethanol were 226 and 100 mW/cm 2 , respectively. The high powe