Evidence by SERS of azide anion participation in ammonia electrooxidation in alkaline medium on nanostructured Pt electrodes

Evidence of the participation of adsorbed azide anion (N-3(-)) in the electrooxidation of ammonia in alkaline medium on nanostructured Pt electrodes has been found by using surface-enhanced Raman spectroscopy. This finding is discussed in terms of the Gerischer-Mauerer's mechanism for ammonia oxidation. The formation of azide anion would take place through the recombination of NH3 and N2H4,ad (and maybe other N2Hx (x = 2-4) species). The results support the Geri scher-Maucrer's mechanism in which partially dehydrogenated ammonia adsorbates are believed to play a role as active intermediates in the selective oxidation of ammonia. (c) 2005 Elsevier B.V. All rights reserved.