Electrocatalytic formation of NO2- at a poly crystalline Ag surface in neutral medium

Electrocatalytic reduction of NO3- at a polycrystalline Ag electrode in the presence of KCl has been investigated. The measurements made by the stationary and hydrodynamic electrodes revealed that the Ag electrode substantially promoted the activity of the NO3- reduction through a two-electron transfer process. The electrochemical investigations suggested that the reduction process follows first order kinetics. In the bulk electrolysis experiments, the rate constants (k(1); 35.1 x 10(-3) min(-1) and k(2): 6.5 x 10(-3) min(-1)) were estimated with respect to NO3- and NO2- reduction, respectively. The voltammetric investigations and the evaluation of rate constants (k(1) > k(2)) established that Ag electrode is efficient in the formation of NO2- from the reduction of NO3-. (C) 2012 Elsevier Ltd. All rights reserved.