Electrocatalytic oxidation of ammonia in the neutral medium using Cu₂O.CuO film immobilized on glassy carbon surface

Electrocatalytic ammonia oxidation reaction (AOR) was executed on the copper oxide layer, electrochemically deposited on a glassy carbon electrode (GCE) surface. The XPS analysis revealed that the oxide film contains 80% Cu(I) and 20% Cu(II) species. The EIS analysis suggests that the resultant surface can catalyze ammonia oxidation reactions efficiently. The as prepared GCE-Cu₂O.CuO favored the neutral medium for executing AOR with a degradation rate of 3.76 × 10⁻⁴ mol min⁻¹ cm⁻². Kinetic investigation shows that ammonia oxidation involves a three electron transfer first-order reaction. Tafel analysis of current–potential polarization curves indicates that species such as NH₃ or NH_ads and NH_2ads intermediates do not influence the reaction rate, which made the electrode unique for carrying out AOR. The formal potential value of AOR was evaluated to be ~0.7 V vs Ag/AgCl (sat.KCl) having standard rate constant (k°) of 5.52 × 10⁻⁶ cm/s.