Dinitrogen reduction on a polypyrrole coated Pt electrode under high-pressure conditions: electrochemical impedance spectroscopy studies

DİDEM BALUN KAYAN; FATİH KÖLELİ

Makale detayları

Dinitrogen reduction on a polypyrrole coated Pt electrode under high-pressure conditions: electrochemical impedance spectroscopy studies

Yazarlar:

DİDEM BALUN KAYAN | FATİH KÖLELİ

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Chemistry 2015 Vol.39 Issue 3

Belge Tipi:

Makale

Yayın Tarihi:

8/2015

Belge Dili:

Türkçe

Document ID (Org No.):

2000726884

Sıklık:

İki Aylık

eISSN:

1303-6130

pISSN:

1300-0527

Özet:

 

The electrochemical impedance spectroscopy (EIS) responses of a polypyrrole (PPy)-coated platinum electrode were investigated during N22_{2}-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 μμ\mu m and optimum potential for ammonia synthesis was -0.150 V under 60 bar N22_{2}-pressure. The impedance responses under these conditions presented the lowest pore resistance value of ca. 2 ΩΩ\Omega  cm22^{2}. The electrolyte resistance was also 2 ΩΩ\Omega  cm22^{2} and the film resistance was ca. 5 ΩΩ\Omega  cm22^{2}. Tafel slopes calculated from the Tafel curve and EIS-Tafel diagram gave corresponding results: 0.121 V dec−1−1^{-1} and 0.128 V dec−1−1^{-1}, respectively; αα\alpha -transfer coefficient of 0.49 and an exchange current density with a value of 3.17 10−3−3^{-3} A cm−2−2^{-2} were characteristic for Hadad_{ad} formation in acidic aqueous medium.

 

The electrochemical impedance spectroscopy (EIS) responses of a polypyrrole (PPy)-coated platinum electrode were investigated during N22_{2}-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 μμ\mu m and optimum potential for ammonia synthesis was -0.150 V under 60 bar N22_{2}-pressure. The impedance responses under these conditions presented the lowest pore resistance value of ca. 2 ΩΩ\Omega  cm22^{2}. The electrolyte resistance was also 2 ΩΩ\Omega  cm22^{2} and the film resistance was ca. 5 ΩΩ\Omega  cm22^{2}. Tafel slopes calculated from the Tafel curve and EIS-Tafel diagram gave corresponding results: 0.121 V dec−1−1^{-1} and 0.128 V dec−1−1^{-1}, respectively; αα\alpha -transfer coefficient of 0.49 and an exchange current density with a value of 3.17 10−3−3^{-3} A cm−2−2^{-2} were characteristic for Hadad_{ad} formation in acidic aqueous medium.

Makale detayları

Dinitrogen reduction on a polypyrrole coated Pt electrode under high-pressure conditions: electrochemical impedance spectroscopy studies

Yazarlar: DİDEM BALUN KAYAN | FATİH KÖLELİ

Yayıncı: TUBITAK

Dergi: Turkish Journal of Chemistry 2015 Vol.39 Issue 3

Belge Tipi: Makale

Yayın Tarihi: 8/2015

Belge Dili: Türkçe

Document ID (Org No.): 2000726884

Sıklık: İki Aylık

eISSN: 1303-6130

pISSN: 1300-0527

Sayı

Yazarlar:

DİDEM BALUN KAYAN | FATİH KÖLELİ

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Chemistry 2015 Vol.39 Issue 3

Belge Tipi:

Makale

Yayın Tarihi:

8/2015

Belge Dili:

Türkçe

Document ID (Org No.):

2000726884

Sıklık:

İki Aylık

eISSN:

1303-6130

pISSN:

1300-0527