Abstract (EN):
The electrocatalysis of the oxygen reduction reaction by lanthanum-strontium manganate La0.5Sr0.5 MnO3 (LSM) 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 was concluded that the oxygen reduction occurs by dissociative chemisorption at low overpotentials. At higher overpotentials, the formation of hydrogen peroxide (HO2- in this case) on the electrocatalyst has been observed. The apparent exchange current density for oxygen reduction on LSM has been found to be 2 x 10(-7) A cm(-2), while the corresponding Tafel slope is 0.100 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