Charge Dilution of Fe–N4 Sites via Te Single-Atom Electron Pumps for Robust Oxygen Reduction

The high desorption energy barrier for OH– hinders the improvement of the oxygen reduction reaction (ORR) and related devices. Here, an Fe-based atom pair catalyst for ORR is discovered through high-throughput density functional theory calculations. The atomic Te around the Fe1–N4 site (Te1–N2–Fe1–N2) served as an electron pump to achieve charge dilution, contributing to an onset potential of 1.03 V and a half-wave potential of 0.94 V. Moreover, a kinetics current density of 32.4 mA cm–2 and remarkable durability up to 20000 continuous electrolysis cycles (1/4 activity decay that of the Fe1–N4 site) were achieved. An ab initio molecular dynamics simulation revealed the formation process of Fe–Te dual atoms. In situ characterization and comparative experiments verify that the charge dilution toward a single Fe site around atomic Te resulted in promoted O2 conversion and accelerated *OH desorption. The corresponding Al-air batteries showed an open-circuit potential of 1.62 V, a power density of 138.1 mW cm–2, and stable voltages during the long-term discharging process (446 h at 10 mA cm–2 and 270 h at 20 mA cm–2). The study demonstrates the single-atom electron pump as an effective strategy for handling the charge density around single-atom sites for electrocatalysis.