Electrochemical determination of ammonia at low concentrations: detection of N2-electroreduction product in alkaline medium

The dataset concerns a catalytic system based on iron phosphide (Fe3P), and it demonstrates the effectiveness of a simple voltammetric approach determination of ammonia at submillimolar concentration in alkaline medium (0.5 mol dm-3 NaOH). The dataset in its collection induces systems’ characterization using electrochemical measurements (files. xlsx)  (cyclic voltammetry and chronocoulometry), SEM (files. tif.), TEM (files. tif.), XRD (file. xlsx) and spectrophotometric methods (files. xlsx). As a rule, nomenclature and scientific terms are consistent with those existing in publication. Electroanalytical approach was based on the voltammetric oxidation of ammonia at the additional platinized working electrode (introduced to electrolytic cell during N2-reduction), and it permitted quantification of ammonia at low concentrations both in blank (argon-saturated) and real (following fixation of nitrogen-saturated) samples without opening the sealed electrochemical cell. Technical details were provided. It should be emphasized that the analyzed sample was not in contact with external environment to avoid uncontrolled contamination. The dataset covers results of diagnostic experiments with different modified (catalytic) electrodes (with Pt and Rh nanoparticles) to address possibility of the formation of hydrazine or hydroxylamine as side NH3-electroreduction products. The reference approach was also included to identify NH3 as a product of N2-reduction at the electrode modified with Fe3P. It was based on the spectrophotometric (VIS) indophenol-blue-method. Monitoring of absorbance at 650 nm had analytical (diagnostic) meaning.