Chapter 3
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Electrochemical Ferrate(VI) Synthesis: A Molten Salt Approach 1
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M. Benová J. Híveš ,K. Bouzek , and V. K. Sharma 1
Department of Inorganic Technology, Slovak University of Technology in Bratislava, 812 37 Bratislava, Slovakia department of Inorganic Technology, Institute of Chemical Technology Prague, 166 28 Prague, Czech Republic Florida Institute of Technology, Melbourne, FL 32901 3
The electrochemical synthesis of ferrate(VI) was studied for the first time in a molten salt environment. An eutectic NaOH-KOH melt at the temperature of 200 °C was selected as a most appropriate system for the synthesis. Cyclic voltammetry was used to characterize the processes taking place on the stationary platinum (gold) or iron electrodes. The identified anodic current peak corresponding to the ferrate(VI) production was close to the potential region at which oxygen evolution begins. During the reverse potential scan, well defined cathodic current peak corresponding to the ferrate(VI) reduction appears. However, the peak was shifted to less cathodic potential than that of potential corresponding to the electrolysis in aqueous solutions. This indicates less progressive anode inactivation in a molten salts environment.
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© 2008 American Chemical Society
In Ferrates; Sharma, V.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.
69 The interest in ferrate(VI) has increased substantially for the last decade because of the development of a high capacity battery (so called super iron battery) and its potential as a multipurpose chemical for water and wastewater treatment (7-9). Ferrate(VI) is able to decompose rapidly many toxic pollutants, including chemical weapons. It is also known to be an efficient disinfecting agent (70,77). Potassium salt of Fe(VI) (K Fe0 ) can be produced by thermal, chemical, and electrochemical techniques {4-16). All of these synthetic techniques have disadvantages in producing ferrate(VI) for its intended uses. The thermal technique uses high temperature (>800 °C) and also gives lower yields (^
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