Redox transformations of adsorbed NO molecules on a Pt(100) electrode

Abstract

Electrochemical behaviour of adsorbed NO molecules on Pt(100) electrode has been studied in perchloric acid solutions by means of cyclic voltammetry. According to literature data, saturated NO adlayer with coverage of ca. 0.5 ML is formed at open circuit conditions in nitrite solution as a result of disproportion reaction. The adlayer is stable in the range of 0.4-0.9 V, NO molecules are oxidized at 0.9-1.1 V and can be reduced to ammonia at potentials less than 0.4 V. Stability of the adlayer depends on surface coverage and extent of the ordering. Unsaturated NO adlayer demonstrates redox transformations NO↔NH 3 at 0.5-0.8 V.

Atomistic Insights into Nitrogen-Cycle Electrochemistry: A Combined DFT and Kinetic Monte Carlo Analysis of NO Electrochemical Reduction on Pt(100)

“…[3][4] Electrochemical denitrification is a promising technology for the removal of NO x species from groundwater and constitutes a plausible alternative to traditional denitrification methods, such as biological and physical separations processes, due to its environmental compatibility, energy efficiency, safety, product selectivity, and potential for use in smaller scale devices. [3][4][5][6][7][8][9][10][11][12][13][14][15] Nitrate and nitrite electroreduction can produce a variety of products, such as NO, N 2 O, N 2 , NH 3 OH + and NH 4 + . [15][16][17] However, NO is proposed to be a key intermediate species that…”

Regularities of nitrate electroreduction on Pt(S)[n(100)x(110)] stepped platinum single crystals modified by copper adatoms

“…2a). As already mentioned above, the processes related to electroreduction of nitrate and its products and electrooxidation of these products on the Pt(100) terraces have already been studied in a series of prior works [20,[28][29][30][31]. Further, we assume that the characteristic peaks observed at similar potentials correspond to essentially the same species and the same products, as those determined in these works.…”

“…The products obtained in the course of nitrate electroreduction on various faces of unmodified and modified platinum have already been determined in a number of works [20,[28][29][30][31]. The attribution of the corresponding peaks in this paper is performed on the basis of the data obtained in these works.…”

“…At higher potentials (0.70-0.85 V), adsorbed hydroxylamine, or even ammonia, is oxidized to NO. The nature of the peak at 780 mV on Pt(100) is described in detail in [30]. One must point out that nitrate reduction currents on the narrow terraces of Pt(210), in the range of 300-500 mV of the negative-going scan, are the lowest, while the nitrate reduction peak at 200 mV is the highest in the studied electrode series: NO is slowly adsorbed on this surface and its intensive reduction starts only in the most negative potential region.…”

“…There is a slight positive shift in the copper dissolution potential. To estimate the amount of copper on the surface, the peak of copper dissolution was integrated from the potential at which the current in the CV passed through zero, to the beginning of the oxygen region for Pt(210) and to the beginning of the NO-nitrite transition for Pt(410) and Pt(610) [30,31], with correction for the background curve.…”