Harnessing Spin-Lattice Interplay in Metal Nitrides for Efficient Ammonia Electrosynthesis.

Wang, Xunlu; Wang, Jiacheng Jayden; Hu, Huashuai; Yin, Congling; Chang, Lo-Yueh; Zhu, Ye; Wang, Jiacheng; Yang, Minghui · Adv Mater · 2025

basic_science · Level V

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Abstract

Metal nitrides, renowned for their spin-lattice-charge interplay, offer vast potential in catalysis, electronics, and energy conversion. However, spin polarization manipulation in these nitrides remains a challenge for multi-electron electrocatalytic processes. This study introduces Co<sub>3</sub>Mo<sub>3</sub>N with a low-spin polarization configuration, achieved by incorporating spin-free lattice Mo with 4d orbitals into high-spin polarization Co<sub>4</sub>N. This innovation delivers outstanding nitrate-to-ammonia electrosynthesis, ranking among the best to date. Mo inclusion induces competing magnetic exchange interactions, reducing the spin polarization degree and enabling rate-determining step of NO<sub>2</sub>* to NO-OH* conversion via vertex-sharing NMo<sub>6</sub> octahedra. A paired electro-refinery with a Co<sub>3</sub>Mo<sub>3</sub>N cathode achieves 2 000 mA cm<sup>-2</sup> at 2.28 V and sustains an industrial-scale current of 1 000 mA cm<sup>-2</sup> for 2,100 h, with an NH<sub>3</sub> production rate of ≈70 mg NH<sub>3</sub> h<sup>-1</sup> cm<sup>-2</sup>. This work establishes a transformative platform for spin polarization degree-engineered electrocatalysts, driving breakthroughs in energy conversion technologies.