Electrocatalytic properties of nitrous oxide and its voltammetric detection at palladium electrodeposited on a glassy carbon electrode

The electrochemical behavior of nitrous oxide (N2O) on the surface of electrodeposited palladium (Pd) was investigated by voltammetry in aqueous supporting electrolytes. It was found that N2O is weakly adsorbed on a Pd/GC electrode and can be reduced electrocatalytically with a high efficiency. The reduction product is not adsorbed on the Pd/GC electrode in aqueous neutral and alkaline solutions. However, it is difficult for N2O to be reduced on the same electrode in acidic electrolyte because hydrogen adsorption competes for the adsorption sites. The concentration of N2O can be quantitatively determined using the electrocatalytic reduction current of N2O at the Pd/GC electrode. This electrode provides a sensitive probe for the electrochemical detection of N2O with a low detection limit and a wide linear response range from 24.3 mu M to 1.94 mM. A mechanism is proposed to account for the electrocatalytic reduction of N2O on the Pd/GC electrode, which adequately explains our experimental observations.