Electrocatalytic activity of copper alloys for NO3- reduction in a weakly alkaline solution. Part 2: Copper-tin

A comparative study has been made of the influence of an addition of Sn to Cu as the basic cathode material on the electrocatalytic activity of the resulting material for nitrate (NO3-) reduction in a weakly alkaline medium. Potentiodynamic and chronoamperometric experiments were carried out in an electrolyte simulating the solution from regeneration of an ion-exchange column for NO3 removal in drinking water treatment. A rotating ring-disk electrode was used for these experiments. An enhancement of the electrocatalytic activity of Cu by alloying with Sn was observed only in the composition region up to 10 wt.% Sn. A further increase in Sn content results in a rapid decline of the electrocatalytic activity caused by changes in the phase structure of the alloy material. For the most active material potentiostatic batch electrolysis was carried out in a divided and an undivided cell. The reduction products were determined.