Electrode kinetics of oxygen reduction on oxide-free platinum electrodes

✍ Scribed by A. Damjanovic; V. Brusic

• Publisher: Elsevier Science
• Year: 1967
• Tongue: English
• Weight: 1001 KB
• Volume: 12
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(67)85030-8

✦ Synopsis

Ah&act-The cathodic V log i curves for On reduction on oxide-free Pt electrodes were determined in oxygen-saturated purhied acid (HClO,, pH l-3) and alkaline (NaOH, pH 13) solutions. It was found that aV/aiogi = -2.3RTlF, .ayalOgp,, = -23RTlF

and W/a pH = -100 mV. Coverage of electrodes by oxy gamammg spectes was determined by superimposing a constant cathodic current over the wor g electrode. Intenmdrate values of coverages were found to be nearly linearly dependent on the e&c&ode potential in the Tafel region.

-The kinetrcs and mechanism of 0. reduction on oxide-free Pt electrode are different from that reported for the oxld~vered electrod:. Reaction mechanisms are discussed in terms of Langmuir and Temkin adsorption isotherms. It is suggested that under Temkin conditions the rate&termining step in the over-all four-electron process is the tlrst electron transfer. R&m&-Les courbes cathodiques i/V pour la reduction de 0, sur &&odes de platine exem tes d'oxvde one 6t6 etablies dans des solutions satur&s d'oxveene. acides (HCIO.. DH 1 a 3) et c&es al (Na&~pIL13).

I1 a et6 trouve que ava log i = --i:3 RTIF: aiqa 10~jor = --i,3 RT/F et W,,apH = -100 mV. Le recouvrement des 6lectrodes par des cornpoSes oxygen& a ete 6tudiC en surimposant un courant cathodique constant a l%lectrode de travail. Il apparait ainsi que dans la region de Tafel, les valeurs des recouvrements intermediaires d6pendent a peu pr& lin6airement de la tension d%lectrode.

La cin&ique et le m&at&me de la reduction de 0, sur Pt exem d&its pour une &&rode recouverte d'oxyde. La discussion en est Lee