Preparation of IrRuO2 coating on bipolar plate for Proton exchage membrane water electrolyzer (PEMWE)

Abstract

Water electrolysis using proton exchange (PEMWE) is an effective method for hydrogen production without CO₂ emission. The most important part in a PEMWE is the bipolar plates (BPPs). They are multifunctional components, ensuring the supply of water and removal of gases in each individual cell and facilitating charge carrier transport between them. The BPPs need to be maintained in the harsh PEMWE-operating environment with low costs and high electrical conductivity. Excellent corrosion resistance is found in Ti and the metal is therefore considered to be the best candidate for BPPs in PEMWE today. However, under the harsh conditions of PEMWE, the titanium material is degraded: brittle, craced and forms a passive oxide layer on the surface, and increasing the ohmic resistance. To overcome this, a thin oxide layer of mixed metallic oxides including IrO₂ and RuO₂ has been considered intensively for coating on the surface of the titanium. In this report, a thin film of IrxRu(1-x)O2 is applied over titanium by thermal decomposition. The XRD, SEM, cyclic voltammetry (CV), anodic polarization, chronoamperometry are employed to determine the physical characteristics and the electrochemical properties of material in 0.5 M H₂SO₄ solution. Based on testing results, the thin film of Ir₅Ru₅O₂ coated bipolar plate having high durability and electric conductivity to serve as BPPs in PEMWE.