Electrocatalysis of Nitrate Reduction at Copper-Nickel Alloy Electrodes in Acidic Media

Autor: Dennis C. Johnson, Brett K. Simpson
Rok vydání: 2004
Předmět:
Zdroj: Electroanalysis. 16:532-538
ISSN: 1521-4109
1040-0397
Popis: The cathodic reduction of NO in 1.0 M HClO4 is investigated by voltammetry at pure Ni and Cu electrodes, and three Cu-Ni alloy electrodes of varying composition, all configured as rotated disks. Voltammetric data obtained using these hydrodynamic electrodes demonstrate significantly improved activity for NO reduction at Cu-Ni alloy electrodes as compared to the pure Ni and Cu electrodes. This observation is explained on the basis of the synergistic benefit of different surface sites for adsorption of H-atoms, generated by cathodic discharge of H+ at Ni-sites, and adsorption of NO at Cu-sites on these binary alloy electrodes. Koutecky-Levich plots indicate that the cathodic response for NO at a Cu75Ni25 electrode corresponds to an 8-electron reduction, which is consistent with production of NH3. In comparison, the cathodic response at Cu50Ni50 and Cu25Ni75 electrodes corresponds to a 6-electron reduction, which is consistent with production of NH2OH. Flow injection data obtained using Cu50Ni50 and Cu25Ni75 electrodes with 100-μL injections exhibit detection limits for NO of ca. 0.95 μM (ca. 95 pmol) and 0.60 μM (ca. 60 pmol), respectively.
Databáze: OpenAIRE
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