Conductive additives for oxide-based OER catalysts: A comparative RRDE study of carbon and silver in alkaline medium

Abstract

The objective of this work is to explore whether carbon materials, which are usually utilized as additives for improving the electronic conductivity of oxide-based oxygen evolution reaction (OER) catalysts, could be replaced by silver nanoparticles. We integrate La0.75Sr0.25Mn0.5Co0.5O3−δ, a perovskite with a limited electronic conductivity, in electrode compositions with either carbon materials (pyrolytic carbon of the Sibunit family – Sibunit-152, furnace black – Vulcan XC-72R, and Acetylene black) or silver nanoparticles, and investigate their OER activity in 1 M NaOH solution. We apply the rotating ring-disk electrode (RRDE) technique to separate the OER currents from those originating from corrosion of the additives under anodic polarization. We conclude that certain carbon materials would be better suited for use as conductive additives for oxide-based OER catalysts than silver particles.