Porous nickel‐coated oxygen evolution anodes were impregnated with nickel hydroxide by electrochemical precipitation methods. A one‐step process produced superior normalNifalse(OH)2 deposit morphology and control over the normalNifalse(OH)2 loading. The quantity of normalNifalse(OH)2 deposited was a linear function of the charge passed during electrochemical precipitation. Oxygen evolution overpotentials in 30 weight percent KOH at 80°C were about 45–60 mV lower on normalNifalse(OH)2‐normalcatalyzed anodes than on similar uncatalyzed anodes. The maximum overpotential reduction was obtained at low normalNifalse(OH)2 loadings. An overpotential increase at higher loadings was caused by plugging of the coating surface pores by normalNifalse(OH)2 , leading to a decrease in effective surface area.

In recent years, considerable progress has been made in developing alkaline water electrolysis anodes. Several laboratories have reported oxygen evolution overpotential reductions of 100-150 mV or more, relative to uncatalyzed nickel. Some candidate anode materials have shown stable operation for thousands of hours under typical commercial electrolysis conditions. Preferred e]ectrocatalysts have been the mixed metal oxides, especially the AB204 spinels and ABO:~ perovskites. Other metal oxides, alloys, and high surface-area forms of nickel have also been studied. This review summarizes recent work in developing practical alkaline water electrolysis anodes.

Electrodes for alkaline water electrolysis have been made by applying high specific surface area coatings of nickel or nickel-iron alloy to steel or nickel substrates. The coatings are applied as polysilicate-based paints containing particles of the desired metals. The coating is sintered into a porous structure which is bonded firmly to the substrate. The present electrode preparation method has been used to coat a variety of substrate forms, such as flat plates or wire screens, and is compatible with commercial alkaline electrolysis equipment. The resulting electrodes were found to be particularly effective as anodes for oxygen evolution. The efficiency of the electrodes was greatly influenced by coating microstructure. This microstructure, in turn, could be controlled by adjusting the sintering conditions. Electrochemical operating characteristics of the electrodes in 30 w/o KOH at 80~ were determined. Comparable oxygen evolution efficiencies were obtained with coatings made from nickel powders, nickel flake, and nickel-iron alloy powder. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 155.33.16.124 Downloaded on 2014-11-02 to IP Vol. 128, No. 4 WATER ELECTROLYSIS 741 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 155.33.16.124 Downloaded on 2014-11-02 to IP

Wiesbaden: Harrassowitz 2013. 314 S., geb., € 42,00. ISBN 978‐3‐447‐10006‐9. Daniel Stolzenberg,­ Egyptian Oedipus: Athanasius Kircher and the Secrets of Antiquity, Chicago/London: University of Chicago Press 2013. XI, 307 S., Ill., $ 50,00. ISBN 978‐0‐226‐92414‐4.

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