Improvement of Mass Activity of IrO x Electrocatalyst in Acidic Oxygen Evolution Reaction Using Bi 3 TaO 7 Support

Developing highly conductive and durable support materials for Ir-based electrocatalysts in acidic oxygen evolution reactions (OER) is one of the challenges to overcoming corrosion conduction during the anodic process. In this study, we develop an oxide-type support material(Bi 3 TaO 7 ) for IrO x electrocatalyst in acidic OER to minimize the amount of iridium loading level. Through a combination of various physical and chemical analyses(XRD, TEM, XRF, EIS, XPS, XAS, etc.), it is demonstrated that the IrO x /Bi 3 TaO 7 electrocatalyst showed remarkable OER performances and enhanced mass activity compared to unsupported IrO x electrocatalysts. Bi on the surface of Bi 3 TaO 7 suppresses the change in oxidation state of Ir element, maintains activity of IrO x electrocatalyst during electrochemical reaction and induces chemical and physical stability of the IrO x /Bi 3 TaO 7 electrocatalyst. These findings can provide further insight into a new category of anode support materials for proton exchange membrane water electrolyzers.