Why Iridium Coated on Titanium Substrate is an Excellent Material for Oxygen Evolution Reaction?

May 31, 2022

Why Iridium Coated on Titanium Substrate is an Excellent Material for Oxygen Evolution Reaction?

The anodic oxygen evolution reaction (OER) has significant importance in many electrochemical technologies. In anodic oxygen evolution reaction (OER), due to the extremely corrosive acidic environment and the high potential required to drive this reaction. Only a few materials are able to meet the necessary requirements to simultaneously provide sufficient reactivity and durability in harsh oxidizing conditions.

Typically those are oxides with metallic-type conductivity, among which only iridium oxides are currently used in acidic water electrolyzers. Iridium is known as the best catalyst material for the OER in acidic media due to its relatively high activity and long-term stability.

Nevertheless, even iridium based catalysts slowly undergo dissolution. Considering the scarcity and high price of iridium, optimization of its utilization and suppression of degradation become of pivotal importance. Mixing of iridium with other more stable materials, for example, titanium typically results in catalysts showing very high stability against dissolution but leads to penalties in terms of reactivity. Iridium coated on titanium substrate can be promising OER catalysts with both high activity and high stability.