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

Abstract

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 NH 3 and N 2H 4,ad (and maybe other N 2H x ( x = 2–4) species). The results support the Gerischer–Mauerer’s mechanism in which partially dehydrogenated ammonia adsorbates are believed to play a role as active intermediates in the selective oxidation of ammonia.