Ir-Based Intermetallic Nanoparticles: Efficient and Durable Catalysts for Oxygen Evolution Reaction

Abstract

Oxygen evolution reaction (OER) plays a crucial role in water splitting technology for efficient, clean hydrogen production, which is essential to realizing a sustainable energy future. However, the active and stable electrocatalysts in corrosive acidic media are limited to costly Ir-based materials. Here, we present chemically stable, atomically ordered IrSn intermetallic nanoparticles dispersed on carbon support (O-IrSn/C) as a high-performing OER catalyst. We prepared O-IrSn/C catalysts with an average nanoparticle size of 4.8 nm, by the combination of impregnation-reduction method and sacrificial silica layer. These O-IrSn/C catalysts exhibited superior OER activity to disordered IrSn alloy catalysts as well as commercial Ir/C and IrO2 catalysts. Importantly, the Ir mass activity of O-IrSn/C is 10- and 66-times higher than those of Ir/C and IrO2. Furthermore, the O-IrSn/C showed a minimal activity loss among the catalysts during the long-term stability test. The enhanced OER activity and stability can be attributed to the intermetallic arrangement. These intermetallic nanoparticles can provide a new direction on the catalyst optimization for water splitting.