In order to improve the catalytic activity of an oxygen evolution electrode, the platinum group metal oxides coated electrodes have been investigated by the chronopotentiometric measurements and the real surf ace area of an electrode has been estimated by the cyclic voltammetry.
Generally, the overpotential characteristics of the electrodes are improved by mixing of platinum group metal oxides. In 1M H2SO4, it was found that the Ti/IrO2-RuO2 complex electrode had a better catalytic activity for the oxygen evolution reaction than of the Ti/IrO2 or Ti/RuO2. The complex electrode was most active among the tested electrodes for oxygen evolution. On the other hand in 5M NaOH the Ti/ RuO2-Rh2O3 complex electrode was found to be most active for the oxygen evolution reaction. The properties of these complex electrodes might be caused fundamentally by the low overpotential characteristics of RuO2 both in acid and in alkaline. The activity of RuO2 was improved by the addition of Rh2O3 or IrO2.
This paper describes process schema, design concept and material component of biggest hydrogen liquefier capable producing 850 L/H constructed by TEISAN Co., Ltd. in 1987. This liquefier will supply big amount of liquid hydrogen applied for development of areaspace and other utilization in Japan.
The Alkali Metal Thermoelectric Converter (AMTEC) or Sodium Heat Engine(SHE) is a thermally regenerative electrochemical system operating between a high temperature source at 900-1300K and a low temperature condenser at 400-SOOK. The AMTEC operation is based on extracting electrical energy from the electrochemical expansion of sodium across an ionic conducting β"-alumina solid electrolyte. Its thermal to electric conversion efficiencies have been predicted to be 20-40% for practical systems and the other AMTEC characteristics are compactness, light weight, no moving mechanical parts, and low maintenance requirements.
This paper reviews the operating principles and the status of AMTEC device experiments.