Mechanistic Studies with Mass Spectroscopic Cyclic Voltammetry: Anodic Oxidation of Hydroxylamine on Pt

Abstract

The anodic oxidation of NHzOH on Pt in neutral and acid solutions was studied using CV, RRDE and Mass Spectroscopic Cyclic Voltammetry. Thus, the i/rfJ-curves obtained could be correlated to the rates of formation of the gaseous products N z, NzO, NO and NO z. Three anodic waves were distinguished, each representing 2e-processes as concluded from the products NOH, NOi and N0 3 -belonging to the respective wave. NO is a side product formed by anodic oxidation of NOH within the raising part of the second wave. A detailed mechanism is proposed on the basis of these findings.

Hydroxylamine electrochemistry at polycrystalline platinum in acidic media: a voltammetric, DEMS and FTIR study

“…For the features E R2 and E R3 the intercepts (extrapolated to zero scan rate) are slightly different from zero in both media, as the NO reductive stripping is paralleled by the H adsorption and slow HAM reduction. Similarly, the small non-zero intercept in case of the oxidation feature E O4 , also observed by Karabinas et al [13] in neutral (buffered) media, may point to the existence of a slow parallel (continuous) oxidation process. Fig.…”

“…It was suggested that nitrate is the main product of HAM oxidation in acidic media and neutral media, while nitrite is perceived as a stable intermediate, particularly in alkaline media. More recently, Karabinas et al [13] presented a detailed study of HAM anodic behavior on polycrystalline Pt in neutral (buffered) and acid solutions by combining voltammetry and on-line differential electrochemical mass spectrometry (DEMS). In their mechanism, the authors accepted the dehydrogenation scenario, resulting in NOH formation.…”

Differential electrochemical mass spectrometry

“…Reaction of nitrogen compounds are therefore well suited for being studied by DEMS. Among these are NO 2 Ϫ [46,47], leading to NO 2 upon oxidation and N 2 O upon reduction, and NH 2 OH [46], leading to a variety of oxidation products. The reduction of NO was also studied on Au simple crystal electrodes [48].…”

Amperometric Sensor for Hydroxylamine Based on Hybrid Nickel‐Cobalt Hexacyanoferrate Modified Electrode

“…According to the previous mechanistic studies about hydroxylamine electrochemistry [38,39], the hydroxylamine oxidation is a multi-electron process in which some intermediates such as HNOH, NOH and HNO 2 are involved. The cyclic voltammograms of 4.0 mmol/L hydroxylamine solution at different scan rates were recorded (not shown).…”