Corrosion Study of Cr-Oxide Ceramics Using Rotating Ring Disk Electrode

Abstract

Proton Exchange Membrane Electrolysis demands new resistant and cheap materials for the anode components, and Cr-based spinels are acid stable ceramics, which may meet the requirements of such application to some extent. This work reports the electrochemical behavior of spinel-structured MnCu 0.25 Cr 1.75 O 4 and NiCr 2 O 4 up to 2.0 V in order to determine the stability/dissolution of such materials when exposed to anodic potential. The ceramic/graphite composite was deposited on a rotating ring disk electrode and scanned while the ring electrode was held at 0.5 V vs SHE. The dissolution of Cr species was observed to happen as the oxidation proceeded by collecting the dissolved products at the ring electrode. HCrO 4 – and MnO 4 – were identified as dissolved products. Analysis of post-test solutions, revealed the difference between chemical and electrochemical corrosion of the materials.