Pt₁Co alloy nanoparticles confined in N-doped carbon nanotubes: An efficient oxygen reduction catalyst for long-lasting rechargeable Zn–air battery

Pt-based catalysts are the most active materials for the oxygen reduction reaction in Zn–air batteries; however, most Pt-based catalysts are unfavorable for the adsorption of OOH* intermediates, which hampers battery efficiency. To address this, a strategy for precisely constructing Pt–Co alloy atomic configurations enables the immobilization and controlled release of OOH* intermediates during the four-electron O₂ reduction reaction. Using the synthetic Pt₁Co alloy nanoparticles encapsulated in N-doped carbon nanotubes (Pt₁Co-NP@NCNTs) as an example, characterization via synchrotron-radiation X-ray absorption fine structure and high-angle annular dark-field scanning transmission electron microscopy confirms that Pt single atoms are uniformly dispersed on Co nanoparticles. In-situ attenuated total reflectance-surface enhanced infrared absorption spectroscopy further verifies that these Pt₁Co alloy nanoparticles facilitate the immobilization of OOH* intermediates and the release of OH* intermediates, ensuring efficient H₂O production through the four-electron pathway. As a result, the Pt₁Co-NP@NCNTs exhibit outstanding oxygen reduction reaction activity with a high half-wave potential of 0.90 V vs. reversible hydrogen electrode (RHE), and when integrated into Zn–air batteries, they deliver a high power density of 141 mW·cm⁻² and an ultralong lifespan exceeding 300 h at 10 mA·cm⁻², outperforming most Pt-based electrocatalysts in rechargeable Zn–air batteries.