Catalytic Effect of Copper Ions on Nitrate Reduction

Conjugate reduction of copper and nitrate from diluted solutions against the background of 3 M phosphoric acid is studied. It is found that copper ions catalyze nitrate reduction. The activation effect is attributed to cuprous ions that form as an intermediate product in the course of electrochemical reduction of cupric cations. The Cu+ ions chemically interact with nitrate yielding active components, which, in contrast to nitrates, can readily discharge at the cathode enhancing the efficiency of total cathodic process and promoting the electrode passivation.