On the Electrooxidation and Amperometric Detection of NO Gas at the Pt-Nafion® ElectrodeReport as inadecuate


On the Electrooxidation and Amperometric Detection of NO Gas at the Pt-Nafion® Electrode


On the Electrooxidation and Amperometric Detection of NO Gas at the Pt-Nafion® Electrode - Download this document for free, or read online. Document in PDF available to download.

Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 10617, ROC





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Abstract The electrochemical oxidation of nitric oxide NO gas at the Pt-Nafion® electrode has been studied at a concentration of 500 ppm. The electrooxidation of NO taking place over a wide potential range can be described by a transcendental equation, from which the half-wave potential of the reaction can be determined. For NO oxidation with appreciable overpotentials but negligible mass-transfer effects, the Tafel kinetics applies. The obtained charge transfer coefficient a and the exchange current density io are 0.77 and 14 mA-cm2, respectively. An amperometric NO gas sensor based on the Pt-Nafion® electrode has been fabricated and tested over the NO concentration range from 0 to 500 ppm. The Pt-Nafion® electrode was used as an anode at a fixed potential, preferably 1.15 V vs. Ag-AgCl-sat. KCl, which assures current limitation by diffusion only. The sensitivity of the electrochemical sensor was found to be 1.86 mA-ppm-cm2. The potential interference by other gases, such as nitrogen dioxide NO2 and carbon monoxide CO, was also studied in the range 0-500 ppm. Both sensitivity for NO and selectivity of NO over NO2-CO show significant enhancement upon using a cyclic voltammetric CV activation, or cleaning procedure. View Full-Text

Keywords: Amperometric sensor; Interference gas; Nitric oxide NO; Pt-Nafionâ electrode; Sensitivity Amperometric sensor; Interference gas; Nitric oxide NO; Pt-Nafionâ electrode; Sensitivity





Author: Kuo-Chuan Ho * , Wen-Tung Hung and Jin-Cherng Yang

Source: http://mdpi.com/



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