TY - JOUR
T1 - Oxidation of ammonia in dilute aqueous solutions over graphite-supported α- and β-lead dioxide electrodes (PbO2@G)
AU - Shih, Yu Jen
AU - Huang, Yao Hui
AU - Huang, C. P.
N1 - Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2017/12/10
Y1 - 2017/12/10
N2 - Graphite-supported α- and β-PbO2 electrodes (PbO2@G) were prepared by electrochemical deposition at appropriate potentials with regard to Pb(II)/PbO2 redox couple under alkaline and acidic conditions, respectively, for studying the direct electro-oxidation of ammonia in aqueous solutions. Results of surface characterization including scanning electron microscopy (SEM), X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) indicated the presence of polymorphs of PbO2@G. Cyclic voltammetry (CV) of the electrolyte containing NH3 indicated mediation of electron transfer by PbO2. At the onset potential of ca. +1.0 to +1.45 V (vs. Hg/HgO), a pathway of NH3 oxidation to nitrogen byproducts, namely, N2, NO2−, and NO3− was proposed. The removal efficiency and selective conversion of ammonia (0.1 M Na2SO4, pH 11, 25 °C) on PbO2@G was determined based on controlled potential experiments.
AB - Graphite-supported α- and β-PbO2 electrodes (PbO2@G) were prepared by electrochemical deposition at appropriate potentials with regard to Pb(II)/PbO2 redox couple under alkaline and acidic conditions, respectively, for studying the direct electro-oxidation of ammonia in aqueous solutions. Results of surface characterization including scanning electron microscopy (SEM), X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) indicated the presence of polymorphs of PbO2@G. Cyclic voltammetry (CV) of the electrolyte containing NH3 indicated mediation of electron transfer by PbO2. At the onset potential of ca. +1.0 to +1.45 V (vs. Hg/HgO), a pathway of NH3 oxidation to nitrogen byproducts, namely, N2, NO2−, and NO3− was proposed. The removal efficiency and selective conversion of ammonia (0.1 M Na2SO4, pH 11, 25 °C) on PbO2@G was determined based on controlled potential experiments.
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U2 - 10.1016/j.electacta.2017.10.060
DO - 10.1016/j.electacta.2017.10.060
M3 - Article
AN - SCOPUS:85032858743
SN - 0013-4686
VL - 257
SP - 444
EP - 454
JO - Electrochimica Acta
JF - Electrochimica Acta
ER -