Capturing Copper Single Atom in Proton Donor Stimulated O-End Nitrate Reduction.

Zuo, Yunpeng; Sun, Mingzi; Li, Tingting; Sun, Libo; Han, Shuhe; Chai, Yang; Huang, Bolong; Wang, Xin · Adv Mater · 2025

basic_science · Level V

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Abstract

Ammonia (NH<sub>3</sub>) is vital in global production and energy cycles. Electrocatalytic nitrate reduction (e-NO<sub>3</sub>RR) offers a promising route for nitrogen (N) conversion and NH<sub>3</sub> synthesis, yet it faces challenges like competing reactions and low catalyst activity. This study proposes a synergistic mechanism incorporating a proton donor to mediate O-end e-NO<sub>3</sub>RR, addressing these limitations. A novel method combining ultraviolet radiation reduction, confined synthesis, and microwave treatment was developed to create a model catalyst embedding Cu single atoms on La-based nanoparticles (p-CNCu<sup>s</sup>La<sup>n</sup>-m). DFT analysis emphasizes the critical role of La-based clusters as proton donors in e-NO<sub>3</sub>RR, while in situ characterization reveals an O-end adsorption reduction mechanism. The catalyst achieves a remarkable Faraday efficiency (FE<sub>NH3</sub>) of 97.7%, producing 10.6 mol g<sub>metal</sub> <sup>-1</sup> h<sup>-1</sup> of NH<sub>3</sub>, surpassing most prior studies. In a flow cell, it demonstrated exceptional stability, with only a 9% decrease in current density after 111 hours and a NH<sub>3</sub> production rate of 1.57 mg<sub>NH3</sub>/h/cm<sup>-2</sup>. The proton donor mechanism's effectiveness highlights its potential for advancing electrocatalyst design. Beyond NH<sub>3</sub> production, the O-end mechanism opens avenues for exploring molecular-oriented coupling reactions in e-NO<sub>3</sub>RR, paving the way for innovative electrochemical synthesis applications.