Effect of Multivalent Cations upon Reduction of Nitrate Ions at the Ag Electrode

Abstract

Cathodic reduction of nitrate ions at a polycrystalline silver electrode was reexamined, particularly, in the presence of La 3ϩ and Al 3ϩ cations in the solution. Although the onset potential for this reaction is located above the zero charge potential of Ag, a marked catalytic effect of La 3ϩ ions, was observed, resulting in a large positive shift of the voltammetric peak associated with nitrate reduction. Electrochemical quartz crystal microbalance measurements demonstrated formation at the electrode surface, close to the onset potential for NO 3 Ϫ reduction, of films assigned to La(OH) 3 and/or Al(OH) 3 in the solutions containing La 3ϩ and Al 3+ ions, respectively. The observed effect of La 3ϩ ions upon nitrate reduction is explained in terms of acid-base catalysis, involving species diffusing as La(III)-nitrate complexes (ion pairs) close to the silver electrode.

A Sensitive Nitrate Ion-Selective Electrode from a Pencil Lead. An Analytical Laboratory Experiment

“…There are many methods for measuring aqueous nitrate concentrations, including spectroscopic (4)(5)(6), chromatographic (7), and electrochemical (8,9) techniques. Such methods often need expensive equipment or require extensive pretreatment procedures that may involve the use of other toxic chemicals.…”

Electrocatalysis of Nitrate Reduction at Copper‐Nickel Alloy Electrodes in Acidic Media

“…The transition metal cathodes exhibited volcano-shaped plots with respect to activity for NO À 3 reduction as a function of M-H and M-O bond energies with optimal activity corresponding to intermediate bond energies [2]. Studies of NO À 3 reduction also have been performed at Cu [3 ± 12], Cd [7,13,14], Pb [15,16] and Ag [4,17] electrodes, and at B-doped diamond electrodes [18 ± 20].…”

Nickel hydroxide electrodeposition from nickel nitrate solutions: mechanistic studies

“…By using linear sweep voltammetry, Fedurco and co-workers [12] have identi®ed the features due to (i) nitrate reduction to nitrite and (ii) nitrite reduction to ammonia. The experiments were carried out on NaNO 3 dissolved in NaClO 4 as a supporting electrolyte using a silver working electrode.…”