Tuning the Bonding Behavior of d‐p Orbitals to Enhance Oxygen Reduction through Push–Pull Electronic Effects

Abstract

The regulation of electronic structure is intricately linked to the intrinsic activity of oxygen reduction. Herein, a strategy for electronic structure modulation induced by bimetallic push–pull electronic effects in dual‐atom catalysts (Fe,Ni/N‐C@NG) is developed. Experiments and theoretical analysis reveal that Fe sites exhibit favorable bonding behaviors (Fe–O: dxz‐p, dyz‐p, and dz2‐p) and spin configurations, which can enable rapid desorption of *OH and thus enhance the intrinsic activity of oxygen reduction. In situ monitoring techniques and Gibbs free energy diagram further demonstrate that the adjacent Ni could serve as second active center to participate in oxygen reduction. The Fe,Ni/N‐C@NG exhibits enhanced oxygen reduction reaction activity and excellent stability. Meanwhile, the assembled Zn–air battery maintains stability for over 300 h with a small voltage gap. This study provides multiple insights into the orbital scale laws of oxygen reduction.

Rapid Surface Reconstruction of Pentlandite by High‐Spin State Iron for Efficient Oxygen Evolution Reaction

“…These findings indicated that the coordination induced by SDS led to a high‐spin state of FNS‐400. On note, the comparison of the high‐resolution Ni 2p XPS spectra of FNS and FNS‐400 revealed a much higher ratio of Ni 2+ /Ni 3+ in FNS‐400 (0.97) than in FNS (0.11) (Table S2), further confirming that the high‐spin configuration of FNS‐400 benefited from the high‐spin state of Fe 3+ [5a,11] . To further confirm the spin state details of Fe, 57 Fe Mössbauer spectra (Figure S9) were collected at room temperature.…”

Tailoring Oxygen Reduction Reaction Kinetics of Fe−N−C Catalyst via Spin Manipulation for Efficient Zinc–Air Batteries

“…It subsequently promotes the reduction of the bond sequence of * OH on Fe (II) from LS to MS (Figure 4e). [ 54,55 ] In this way, the adsorption of * OH on Fe SA/AC @HNC will be weaken, by which the kinetics of ORR could be boosted. Next, electron transfer behaviors were examined by charge density difference and Bader charge (Figure 4f; and Figure S41, Supporting Information).…”

Anion doping and interfacial effects in B-Ni5P4/Ni2P for promoting urea-assisted hydrogen production in alkaline media

“…S12d †), indicating that the incorporation of B has a certain impact on the electronic structure of both Ni 5 P 4 and Ni 2 P phases. Before B is doped, the t 2g orbit of the d orbital of the Ni site is completely occupied, so there is an initial electron repulsion between Ni and P. 21 After B replaces part of P, the electronegativity of B is weaker than that of P, causing a rearrangement of the electronic structure around Ni (Fig. 3g and h).…”