Electrochemical oxidation of borohydride on platinum electrodes: The influence of thiourea in direct fuel cells

• Type: Article in International Scientific Journal
• Date: 2007

Authors

J.I. Martins (Author) FEUP; M. C. Nunes (Author) FEUP; R. Koch (Author) FEUP; L. Martins (Author) FEUP; M. Bazzaoui (Author) FEUP

Journal

Title: Electrochimica Acta

Vol. 52 No. 11

Pages: 6443-6449

ISSN: 0013-4686

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 78 Citations

ISI Web of Science

Scopus - 89 Citations

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

Other information

Authenticus ID: P-004-8VG

DOI: 10.1016/j.electacta.2007.04.066

Abstract (EN): The electrochemical behaviour of sodium borohydride on a platinum electrode in the absence and presence of thiourea (TU) was investigated by cyclic voltammetry. In the absence of thiourea, several overlapping peaks associated. with the hydrolysis of BH4(-) appear in the domain of hydrogen oxidation, i.e., in the potential range of -1.25 to -0.50V versus Ag/AgCl. As a consequence of secondary reactions, the borohydride oxidation in 3 M NaOH solution shows a four to six-electron process, according to its concentration, in direct fuel cells. A conveyable TU/NaBH4 concentration ratio of 0.6 inhibits the delivery of hydrogen simultaneously with catalytic hydrolysis of BH4(-). Thus, the coulombic efficiency in direct fuel cell discharge was increased showing an about eight-electron process for the oxidation of BH4-.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7