Circumventing Scaling Relations via Gradient Orbital Coupling Promotes Ammonia Electrosynthesis on Cobalt Catalyst

Hanle Liu; Shunhan Jia; Limin Wu; Ruhan Wang; Libing Zhang; Xinning Song; Xingxing Tan; Xiaodong Ma; Xiangyuan Jin; Hang Guo; Xiqing Sui; Qian Li; Rongjuan Feng; Lihong Jing; Qingli Qian; Jianling Zhang; Lei He; Xiaofu Sun; Buxing Han

doi:10.1002/anie.202510478

Circumventing Scaling Relations via Gradient Orbital Coupling Promotes Ammonia Electrosynthesis on Cobalt Catalyst

Angew Chem Int Ed Engl. 2025 Jun 3:e202510478. doi: 10.1002/anie.202510478. Online ahead of print.

Authors

Hanle Liu^{1

2}, Shunhan Jia^{1

2}, Limin Wu^{1

2}, Ruhan Wang^{1

2}, Libing Zhang^{1

2}, Xinning Song^{1

2}, Xingxing Tan¹, Xiaodong Ma¹, Xiangyuan Jin^{1

2}, Hang Guo³, Xiqing Sui^{1

2}, Qian Li¹, Rongjuan Feng¹, Lihong Jing¹, Qingli Qian^{1

2}, Jianling Zhang^{1

2}, Lei He³, Xiaofu Sun^{1

2}, Buxing Han^{1

2}

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
² School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
³ State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.

PMID: 40458913
DOI: 10.1002/anie.202510478

Abstract

Highly efficient electrocatalytic nitrate reduction to ammonia (NH₃) relies on the balanced activation of various substrates including nitrate and water, but is currently hindered by the inherent scaling relations governing the adsorption of key reaction intermediates, such as *NO and *H. Herein, we develop a strategy to circumvent these limitations by introducing f-d-p gradient orbital coupling in cobalt oxide (Co₃O₄) through Ce doping. Density functional theory calculations indicate that the lattice strain triggered by the dopant redistributes electron density at the Co and O sites, thereby modulating the adsorption strengths of *NO and *H, which favors the production of NH₃ while suppressing hydrogen evolution reaction. It exhibits a faradaic efficiency of 97.8% and a high yield rate of 3423.0 µg h^-1 cm^-2 under alkaline conditions. Furthermore, Ce/Co₃O₄ catalyst shows robust performance over a wide range of nitrate concentrations (from 5 to 200 mM) and excellent cycling stability. Our findings also suggest that the gradient orbital coupling approach can be extended to other lanthanide dopants (e.g., Pr and Nd), offering a broadly applicable platform to break scaling relations and improve NO₃ ^--to-NH₃ activity on cobalt catalysts.

Keywords: Electrocatalysis; Green and sustainable chemistry; Nitrate reduction; Rare earth metal; Scaling relation.

Abstract

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