Electrocatalytic reduction of NO 2− and NO 3− ions at a platinized platinum electrode in alkaline medium

Abstract

The electrocatalytic reduction of NO − 3 and NO − 2 ions was studied at platinized platinum electrodes in the presence of 1 mol dm −3 NaOH supporting electrolyte. Steady state polarization curves were taken by point-by-point potentiostatic measurements at different concentrations in the potential range 0–400 mV (on RHE scale). In both cases a sharp maximum appears on the polarization curves at low potentials (100–250 mV). In the case of NO 2 − ions a less pronounced second maximum may be observed at more positive potentials. The position of the maxima depends on the concentration of the reacting species. It is assumed that the polarization behaviour observed is connected with competitive adsorption phenomena.