Balun Kayan, DidemKöleli, Fatih2019-07-112019-07-1120151300-0527https:/dx.doi.org/10.3906/kim-1501-80https://hdl.handle.net/20.500.12451/2166Balun Kayan, Didem (Aksaray, Yazar)The electrochemical impedance spectroscopy (EIS) responses of a polypyrrole (PPy)-coated platinum electrode were investigated during N2 -reduction to ammonia in aqueous medium. Kinetic parameters such as film resistance, pore resistance, and double layer capacitance were analyzed as a function of applied potential and polymer film thickness. The relation between kinetic parameters was discussed by combining electrolysis results. It was found that the optimum film thickness of polypyrrole was 0.73 µm and optimum potential for ammonia synthesis was –0.150 V under 60 bar N2 -pressure. The impedance responses under these conditions presented the lowest pore resistance value of ca. 2 ? cm2 . The electrolyte resistance was also 2 ? cm2 and the film resistance was ca. 5 ? cm2 . Tafel slopes calculated from the Tafel curve and EIS-Tafel diagram gave corresponding results: 0.121 V dec ?1 and 0.128 V dec ?1 , respectively; ?-transfer coefficient of 0.49 and an exchange current density with a value of 3.17 10 ?3 A cm ?2 were characteristic for Had formation in acidic aqueous medium.eninfo:eu-repo/semantics/openAccessDinitrogen ReductionConducting Polypyrrole CoatingHigh Pressure ReactionElectrochemical İmpedance SpectroscopyArticle39364865910.3906/kim-1501-80Q3N/A