Oxygen reduction reaction on palladium-modified zeolite 13X

Abstract

Palladium was dispersed over zeolite NaX by procedure of impregnation/thermal degradation of palladium acetylacetonate salt. Samples characterization was performed by X-ray diffraction, SEM analysis, and chemical analysis. Palladium was present in modified zeolite as palladium oxide with content estimated to be about 8 wt.%. Electrochemical behavior of synthesized material was investigated in 0.1 M NaOH. The influence of addition of carbon black to composite electrode on its electrocatalytic performance was also investigated. The addition of carbon black altered the shape of voltammogram. The separated peak of reduction of alpha and beta palladium oxides was visible only on voltammograms recorded without carbon black. Composite electrodes with and without carbon black were tested for oxygen reduction reaction. According to Koutecky-Levich slope, the oxygen reduction reaction followed 4e(-) mechanism on both electrodes. The onset of oxygen reduction reaction (ORR) on the electrode with added carbon black was shifted toward more positive potentials in comparison to the electrode without carbon black.