Interatomic Fe–Cu cooperation in nitrogen-doped carbon for enhanced oxygen reduction

Abstract

The development of robust and electrocatalytically active catalysts for the oxygen reduction reaction (ORR) remains a significant challenge in advancing electrochemical energy technologies. Here, we report a Fe–Cu dual-metal catalyst embedded in nitrogen-doped porous carbon (FeCu–NC), synthesized via a controllable host–guest encapsulation strategy to enhance charge and mass transfer in the ORR. The FeCu–NC catalyst exhibits impressive ORR performance, with half-wave potentials of 0.918 V and 0.805 V in alkaline and acidic media, respectively, surpassing that of commercial Pt/C (0.889 V) in alkaline media and approaching its activity (0.835 V) under acidic conditions. Moreover, the catalyst demonstrates remarkable stability with negligible degradation in accelerated degradation testing. Density functional theory calculations reveal strong Fe–Cu interactions that optimize intermediate adsorption energies, enhancing catalytic efficiency. In practical applications, the FeCu–NC catalyst delivers high peak power densities of 250.3 mW cm⁻² in zinc–air batteries and 0.58 W cm⁻² in proton exchange membrane fuel cells. It also exhibits impressive long-term stability compared to other reported non-precious metal catalysts. These findings provide valuable insights for designing advanced catalysts for a wide range of electrocatalytic processes.