Boosted N₂ Activation through 4f–2p–3d Orbital Hybridization for Efficient Nitrate Electrosynthesis

Abstract

The electrochemical N2 oxidation reaction (NOR) has emerged as a promising approach for achieving high selectivity in nitric acid (HNO3) production. However, the sluggish N2 activation process in NOR due to the high cleavage energy barrier of the N≡N bond remains a challenge. Herein, a novel orbital hybridization strategy for tuning the NOR performance through the construction of cerium (Ce) 4f–O 2p–Co 3d network in Ce‐doped Co3O4 (Ce–Co3O4) is proposed. The Ce–Co3O4 catalyst exhibits an enhanced HNO3 yield of 24.76 µg h−1 mgcat−1 and a promoted Faradaic efficiency of 31.93% in 0.1 m Na2SO4 electrolyte under ambient conditions compared to those of the pure Co3O4 (13.75 µg h−1 mgcat−1 and 23.43%). Density functional theory caculations demonstrate the strong 4f–2p–3d orbital hybridization and electron transfer in Ce–Co3O4. Moreover, a series of in situ techniques provide direct evidence of stronger adsorption peaks for Co─N bond and the key intermediate *NO formed after N2 activation on the surface of Ce–Co3O4. This work provides a promising route for the preparation of efficient NOR catalysts and sheds light on the mechanism of N2 activation through orbital hybridization.

Manipulating Superexchange Interaction of Ru–O–Fe Sites for Enhanced Electrocatalytic Nitrate-to-Ammonia Selectivity

“…In LF 0.9 R 0.1 O, the 3d orbitals of Fe adjacent to Ru are closer to the Fermi level, whereas the d xy and d z 2 orbitals occupy higher energy levels. As shown in Figure e, there is a strong 3d–2p–3d orbital hybridization between the Ru 3d bands, the O 2p bands, and the Fe 3d bands . Next, we compared the 3d orbital changes of Fe before and after the introduction of other metals (Cr, Mn, Co, Ni) (Figure S19).…”

Revealing the Adsorption Behavior of Nitrogen Reduction Reaction on Strained Ti2CO2 by a Spin‐Polarized d‐band Center Model

“…In recent studies, a wide range of catalysts, including transition metals, metal oxides, 2D materials, and their derivatives like single-atom, dual-atom, and singlecluster catalysts, [3] have been developed for electrocatalytic reactions. In addition to catalysts development, various strategies have been employed to finely tune the electronic structure of materials, [4] including heterojunction, [5] heteroatoms doping, [6] defect engineering, [7] and strain engineering. [8] Among these strategies, strain engineering has emerged as a simple and effective way to precisely modify the physical and chemical properties of materials.…”

NiFeB-assisted adsorption and activation of nitrogen to improve the photooxidation activity of zinc porphyrin

“…4,26–28 It should be noted that transition metals possess vacant d orbitals that may serve as Lewis acid active sites by absorbing electrons from the bonding orbitals of the N 2 molecule 3 σ g , thereby favouring N 2 adsorption and activation. 13,29–35 Hence, in this study, we aimed to address the challenges of nitrogen adsorption and activation in the nitrogen fixation reaction by introducing NiFeB hydroxides as a co-catalyst alongside the primary catalyst ZnTCPP. As expected, the nitrogen oxidation performance could be significantly enhanced by 2.4 times, from 278.2 to 689.4 μmol g −1 h −1 .…”