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

The electrochemical behavior of nitrous oxide ([N.sub.2]O) on the surface of electrodeposited palladium (Pd) was investigated by voltammetry in aqueous supporting electrolytes. It was found that [N.sub.2]O 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 [N.sub.2]O to be reduced on the same electrode in acidic electrolyte because hydrogen adsorption competes for the adsorption sites. The concentration of [N.sub.2]O can be quantitatively determined using the electrocatalytic reduction current of [N.sub.2]O at the Pd/GC electrode. This electrode provides a sensitive probe for the electrochemical detection of [N.sub.2]O with a low detection limit and a wide linear response range from 24.3 [[micro]meter] to 1.94 mM. A mechanism is proposed to account for the electrocatalytic reduction of [N.sub.2]O on the Pd/GC electrode, which adequately explains our experimental observations.