Modulation of electronic spin state and construction of dual-atomic tandem reaction for enhanced pH-universal oxygen reduction

Combining both advances of electronic spin state modulation and tandem reaction mechanism, an atomic-level dual iron-copper catalyst is designed for enhanced oxygen reduction capability. Herein, the intense interaction between the iron-copper site and its coordination environment can not only controls the flow of external charge at the atomic level, but regulates the internal 3d electron configuration. These modulations can optimize the orbital interaction and pair hardness (eta DA) between the acceptor and the donor, and achieves a fast tandem reaction kinetics, thereby surmounting the limitation of Scaling Relation. The as-prepared bimetal catalyst validates a high ORR activity and stability, which even exceed those of the benchmark Pt/C in pH-universal electrolytes. Meanwhile, Fe,Cu/N-C driven Zn-air batteries in alkaline and neutral electrolytes show promi-nent performance with peak power densities of 173.7 mW cm-2 and 86.5 mW cm-2. This work provides a useful design principle for developing or optimizing other efficient ORR catalysts.

Automated summary

By combining the advancements in electronic spin state modulation and tandem reaction mechanism, a dual iron-copper catalyst is designed at the atomic level to enhance oxygen reduction capability. The catalyst achieves intense interaction between the iron-copper site and its coordination environment, which not only controls charge flow at the atomic level, but also regulates electron configuration. These modulations optimize orbital interaction and pair hardness between acceptor and donor, resulting in fast tandem reaction kinetics that overcomes the limitations of Scaling Relation. The bimetal catalyst demonstrates high activity and stability in oxygen reduction, even outperforming the benchmark Pt/C in pH-universal electrolytes. Furthermore, Fe,Cu/N-C driven Zn-air batteries show excellent performance in alkaline and neutral electrolytes. This work provides a useful design principle for developing or optimizing other efficient oxygen reduction catalysts.