SULFUR ELECTRODES FOR Na-S CELLS 709 zation rates which these cells have operated at for more than a year now is a significant advance on the sulfur electrode position of 12 months ago, and gives tremendous encouragement for the further development of the sodium-sulfur battery to a commercially viable product. AcknowledgmentI am indebted to my colleague Graham Robinson who initiated most of the early work leading up to this study and who contributed by helpful discussions throughout.

DICYANOAURATE 723 3. The proposed mechanism explains readily the features of the anodic dissolution of gold in alkaline cyanide electrolyte.

We observed CO2 reduction to CH3OH at various oxidized copper electrodes at 22~ The electrode types included anodized Cu foil, Cu foil thermally oxidized in air, and air-oxidized Cu electrodeposited on anodized or air-oxidized Ti foil. The highest rates to date, 1 • 10 4 mol cm -2 h -1 (geometrical area), were found using anodized Cu in 0.5M KHCO3, pH = 7.6, and -1.9 V (SCE). Faradaic yields for CH3OH depended on the current and reached about 240%. The onset potential for CH3OH formation was near -0.4 V (SCE). Hydrogen gas and small amounts of CO were also formed. A mechanism is proposed involving chemical reduction steps up to HCOad, followed by three hydiogenation steps to CH3OH. Absorption of oxygen by Cure is implied. The stability of p-Cu20 semiconductor films is discussed in terms of breakdown currents d/le to band-to-band tunneling. The major impurities deposited on the Cu electrode during electrolysis are Zn and Fe at several atom percent each. An 8% level of C1 was found, originating from the HC1 etch used to remove the native oxide before thermal oxidation.

No abstract