Stable Cu<sup>δ+</sup> sites derived from analogous rectifying interface in AgCu biphasic aerogels for efficient urea electrosynthesis at low potential.

Feng, Pingyi; Wang, Shao; Dai, Zechuan; Chen, Yanxu; Zhang, Bocheng; Cheng, Mingyu; Ke, Buqi; Xia, Jing et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Urea electrosynthesis through CO<sub>2</sub> and NO<sub>3</sub><sup>-</sup> coupling presents a promising alternative to energy-intensive industrial processes. However, intricate catalytic mechanisms and competitive reactions impede achieving high-efficiency C-N coupling. Herein, we constructed analogous rectifying interfaces in AgCu biphasic aerogels, by leveraging electronegativity difference to derive stable Cu<sup>δ+</sup> active sites, which simultaneously promoted *NOH adsorption and *CO coverage, thereby improving C-N coupling dynamics, confirmed by both operando technique and theoretical calculations. Specifically, notable urea yield (54.8 mmol h<sup>-1</sup> g<sub>cat.</sub><sup>-1</sup>) with Faradaic efficiency (FE, 36.6%) at a low potential (-0.52 V vs. RHE) was achieved using Ag<sub>67</sub>Cu<sub>33</sub> in a flow-cell. As a proof-of-concept demonstration for practicability, Ag<sub>67</sub>Cu<sub>33</sub> exhibited bifunctional electrosynthesis for urea (FE: 56.07%, yield: 104.6 mmol h<sup>-1</sup> g<sub>cat.</sub><sup>-1</sup>) and HCOOH (FE: over 90%) at 40 mA cm<sup>-2</sup> in two-electrode system, with durability over 60 h. This work provides an indicative rationale to construct active sites for C-N coupling, facilitating the development of urea electrosynthesis.