Oxygen, electrolytic production

Chlorine-oxygen compounds discussed here are hypochlorite CIO-, chlorite CIO/-, chlorate CIO/", perchlorate CIO]/, and chlorine dioxide CIO2. With the exception of chlorite, all chlorine-oxygen compounds mentioned can be obtained as a direct product of electrolysis, but electrolytic production is not dominating in all cases. There are chemical pathways, too, using molecular chlorine and caustic alkali as basic educts - which have been produced electrolytically before. 

In case of electrolytic production of chlorine oxygen compounds, questions like purification of brine and of products arise, too. These questions are solved in analogy to the means described in Sect. 5.23.4 and shall not be repeated here. 

Due to the sequential biodegradation pathway (Fig. 19.1), a sequential electrolytic production of hydrogen and oxygen holds the opportunity to stimulate the reductive dechlorination of the higher chlorinated compounds (PCE, TCE) down-gradient the cathode in the first step and subsequently the oxidative degradation of the lower chlorinated metabolites (cA-DCE, VC) down-gradient the anode. The... 

Losses associated with electrolyte conductivity and oxygen/hydrogen product gas management (related to relative electrode placement, ionic pathways between electrodes, possible membrane separators, and other related design features) need to be minimized. 

Zhang, Z., et al., Increased Stability toward Oxygen Reduction Products for Lithium-Air Batteries with OUgoether-FunctionaUzed Silane Electrolytes. 7. Phys. Chem. C 2011, 775, 25535-25542. 

In the allied technology of electrolytic production of chlorates, cathode current efficiencies are not as good as in chlor-alkali electrolysis. Oxygen contents are higher, and the heat of oxidation is substantial. It may then be necessary to carry out the reaction in two stages with intercooling. 

THE PROBLEM Calculate the open-circuit voltage for the electrolytic production of oxygen and hydrogen from a 6 molal potassium hydroxide electrolyte. The temperature is 378 K and the pressure, 15 atmospheres. 

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