Coupled Pd δ- -Cu δ + Dipole for Enhanced Aqueous Nitrate Valorization at Ultralow Potentials

作者：Huihuang Chen, Jiayin Li, Runze Shi, Yue Wu, Bing Zhou, Yancai Yao, Zhigang Geng, Lianzhou Wang, Lizhi Zhang, Maohong Fan, Bo Yang · 发表于：ACS Nano · 年份：2025 · DOI：10.1021/acsnano.5c09566 · 被引用次数：9 · 研究领域：Ammonia Synthesis and Nitrogen Reduction、Catalytic Processes in Materials Science、Nanomaterials for catalytic reactions

Nitrate ( NO 3 − ) pollution poses significant threats to water quality and the global nitrogen cycle. The electrochemical NO 3 − reduction reaction (NO 3 RR) emerges as a promising solution for NO 3 − removal and sustainable ammonia (NH 3 ) production. However, it suffers from an insufficient atomic hydrogen (*H) supply and poor nitrite ( NO 2 − ) adsorption at low potentials, which results in restrained NO 3 − -to-NH 3 conversion and notorious NO 2 − accumulation. Herein, we propose a dipole strategy that utilizes coupled divergent dual centers (Pd δ− -Cu δ+ ) in binder-free monolithic single-atom alloy electrodes (Pd 1 Cu) to overcome these challenges at ultralow potentials. In-situ experiments and theoretical simulations reveal that the polarized atomic Pd δ− dramatically enhances *H supply by facilitating water dissociation into *H, which then readily spills over to the adsorption-strengthened NO 2 − on adjacent Cu δ+, thus promoting rapid deep hydrodeoxygenation at ultralow potentials. Furthermore, the upshifted d -band center inhibits *H self-coupling and reduces the thermodynamic energy barrier for the *NO intermediate hydrogenation. Leveraging these advantages, the coupled Pd δ− -Cu δ+ dipole achieved 100% NO 3 − removal, 100% NH 3 selectivity, near-zero NO 2 − accumulation, 94.4% NH 3 Faradaic efficiency, and an NH 3 yield rate of 1.98 mM h –1 cm –2 at just −0.2 V vs RHE, outperforming the monometallic counterparts and reported advanced catalysts. The proposed metal...