Oxygen reduction at a manganate electrocatalyst in KOH solutions

• Type: Article in International Scientific Journal
• Date: 2006

Authors

Sequeira, CAC (Author) Other; Baptista, W (Author) Other

Journal

Title: Journal of the Brazilian Chemical Society

Vol. 17

Pages: 910-914

ISSN: 0103-5053

Publisher: Sociedade Brasileira de Quimica

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 4 Citations

Other information

Authenticus ID: P-004-HN0

DOI: 10.1590/s0103-50532006000500014

Abstract (EN): The electrocatalysis of the oxygen reduction reaction by lanthanum calcium manganate, (La0.5Ca0.5MnO3) (LCM) has been studied by cyclic voltammetry using the rotating ring-disc electrode technique (RRDE) in alkaline medium. From the ring-disc data and other kinetic parameters it has been assumed that the oxygen reduction occurs by dissociative chemisorption at low overpotentials. At higher overpotentials, the formation of hydrogen peroxide (HO2- in this case) has been observed on this electrocatalyst. The apparent exchange current density value for oxygen reduction on LCM has been found to be 5 x 10(-8) A cm(-2), while the corresponding Tafel slope is 0.115 V per decade. The possible reaction mechanism for electroreduction of oxygen on this oxide catalyst has been discussed.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5