Pt–Ir Alloy-Supported Ti₂CT_x MXene: Unlocking Superior Dual-Function Electrocatalysis for Enhanced-Power Zinc–Air Batteries

Zinc-air batteries (ZABs) are promising energy storage technologies for sustainable energy in the near future due to their high energy density and environmental friendliness. For efficient performance of ZABs, electrocatalysts with superior bifunctional activity are highly desired to reduce the overpotential of oxygen reduction (ORR) and oxygen evolution (OER) reactions, together with long-term reliability ensuring sustained activity with minimal to no significant degradation. This study presents a comprehensive investigation into the catalytic and electrochemical properties of Pt–Ir/Ti 2 CT x ─highlighting their potential as high-performance catalysts for OER and ORR in rechargeable zinc-air batteries. In-depth morphological, structural, and electronic characterizations of the Pt–Ir/Ti 2 CT x electrocatalyst reveal strong metal-support interaction evaluated by a comprehensive XPS analysis between Pt–Ir nanoparticles and Ti 2 CT x support those results in enhanced ORR and OER activity. Detailed electrochemical measurements reveal that the Pt–Ir/Ti 2 CT x catalyst reaches a high ORR onset potential of 1.06 V and a low OER overpotential of 1.53 V vs RHE, much higher than the commercial Pt–Ru/C catalyst. Extended cycling tests also show that Pt–Ir/Ti 2 CT x possesses outstanding stability with marginal performance deterioration after 20,000 cycles, confirming its excellent durability and ensuring the ZABs’ long-term reliability. While evaluating in ZAB, Pt–Ir/Ti 2 CT x bifunctional catalyst, delivered a maximum power density of 323 mW/cm 2, superior rate capability, and negligible charge transfer resistance, suggesting Pt–Ir/Ti 2 CT x as a promising, high-efficiency catalyst for next-generation ZAB technologies.