Electroreduction of nitrate ions in concentrated sodium hydroxide solutions at lead, zinc, nickel, and phthalocyanine-modified electrodes.

摘要

The electrochemical reduction of nitrate in strongly alkaline solution has been studied using nickel, lead, zinc, and iron cathodes. Intermediate formation of nitrate ion and ammonia product was observed for all electrode materials. Coating a nickel sponge electrode with phthalocyanine renders it less active toward nitrate reduction, while iron electrodes appear to be activated. Electrolysis between a lead cathode and a nickel anode is an efficient means of removing nitrate from strongly alkaline solutions. Electrode pretreatment and solution conditions were chosen to correspond to those that might be encountered in practical applications, for example, the cleanup of radioactive waste solutions.