Electrolytic Ozone

Abstract

Recent investigation has shown that ozone can be efficiently prepared by electrolysis of perchloric acid at low temperatures. Free of nitric oxide and other acid impurities, electrolytic ozone was directly obtained at concentrations above 20 weight‐per cent. Depending on cell design, the diluent gases are either oxygen or a mixture of hydrogen and oxygen. We have also found that a variable heretofore generally overlooked in current efficiency studies—the effect of reducing the absolute pressure over the electrolyte—can have a marked effect on current efficiency. Improved ozone yields are obtained at absolute pressures of 0.1 atmosphere. With cells of the type reported herein, eutectic mixtures of perchloric acid and water give excellent results at temperatures below −50°C. Sodium and magnesium perchlorates may be added to perchloric acid solution to give slightly lower melting points, with indication of some increase in current efficiency. Provided a partially frozen electrolyte is used, current efficiency does not vary appreciably over a wide current density range. Smooth platinum is a satisfactory anode material and silver‐free lead is suitable for the cathode. The consumption of platinum is known to be less—probably much less—than 10 milligrams per kilogram of ozone. The combined mechanical and chemical losses of perchloric acid are less than 1.7 grams per kilogram of ozone. For the direct preparation of relatively pure Ozone at high concentrations, the process described is more efficient than the silent electric discharge method.

Oxygen Overvoltage in Concentrated Acid Solutions

“…The ozone current efficiency goes through a minimum as the current density is further increased. A still further increase in current density will raise the current efficiency to better than 30% as has been reported previously (1).…”

The Reactions Of Ozone With Organic Compounds

“…Ozone can be made by the electrolysis of sulfuric acid or perchloric acid solutions (85,86,100,128,155,361,459,497) in concentrations as high as 58 per cent (361). A practical laboratory ozonator of this type has been described (85,86).…”

Anion Exchange and Non-aqueous Studies of the Anionic Chloro Complexes of the Hexavalent Actinides

“…This was then oxidized to Pu(VI) by treatment with electrolytically produced ozone. 17 In one case the plutonium solution was heated with a heat lamp during the oxidation. This appeared to increase the rate of plutonium oxidation considerably, but the oxidation of HC1 by ozone'was increased to such an extent that periodic addition of concentrated hydrochloric acid was necessary to prevent hydrolysis of the remaining Pu(IV).…”