biostudies-literatureUnknown16(41)Mu MElectrocatalytic nitrate reduction (NO₃RR) to ammonia presents a sustainable route for pollutant remediation and green synthesis, yet challenges persist in achieving high efficiency and selectivity. Herein, we report a cobalt-doped copper aerogel (Cu₉₅Co₅) synthesized <i>via</i> one-step co-reduction, demonstrating exceptional NO₃RR performance with 94.91% faradaic efficiency at -0.6 V and 31.15 mg per mg_cat per cm² per h NH₃ yield at -0.7 V <i>vs.</i> RHE. The system achieves an impressive energy efficiency of 31.03% and enables a record-low ammonia production cost of $0.53 per kg. Multiscale characterization reveals that Co doping induces lattice contraction, optimizes d-band positioning, and enhances interfacial K⁺·H₂O interactions, collectively promoting water dissociation and *H generation. The combination of <i>operando</i> spectroscopies (SERS, ATR-FTIR, DEMS) and density functional theory (DFT) calculations elucidates a stepwise hydrogenation pathway: *NO₃ → *NO₂ → *NO → *NH₂OH → *NH₃, with the rate-determining step (RDS) identified as *NO hydrogenation to *NHO. The hierarchical porosity of the aerogel facilitates mass transport while Cu-Co synergy suppresses hydrogen evolution reactions <i>via</i> electronic modulation. Practical viability is demonstrated through stable 12 hour operation in a Zn-NO₃ ^- battery. This work provides insights into Cu-Co catalysis and establishes design principles for high-performance NO₃RR systems.Chemical science19436-19447https://www.ebi.ac.uk/biostudies/studies/S-EPMC12459286biostudies-literatureInsights into interfacial water and key intermediates on Cu&lt;sub&gt;95&lt;/sub&gt;Co&lt;sub&gt;5&lt;/sub&gt; aerogels for electrocatalytic nitrate-to-ammonia conversion.PMC12459286Chen JZhao BQi RXue XMu MShao XYang YShang LJiang WChen ZJWang YLiu DSong WfalseInsights into interfacial water and key intermediates on Cu&lt;sub&gt;95&lt;/sub&gt;Co&lt;sub&gt;5&lt;/sub&gt; aerogels for electrocatalytic nitrate-to-ammonia conversion.Electrocatalytic nitrate reduction (NO₃RR) to ammonia presents a sustainable route for pollutant remediation and green synthesis, yet challenges persist in achieving high efficiency and selectivity. Herein, we report a cobalt-doped copper aerogel (Cu₉₅Co₅) synthesized <i>via</i> one-step co-reduction, demonstrating exceptional NO₃RR performance with 94.91% faradaic efficiency at -0.6 V and 31.15 mg per mg_cat per cm² per h NH₃ yield at -0.7 V <i>vs.</i> RHE. The system achieves an impressive energy efficiency of 31.03% and enables a record-low ammonia production cost of $0.53 per kg. Multiscale characterization reveals that Co doping induces lattice contraction, optimizes d-band positioning, and enhances interfacial K⁺·H₂O interactions, collectively promoting water dissociation and *H generation. The combination of <i>operando</i> spectroscopies (SERS, ATR-FTIR, DEMS) and density functional theory (DFT) calculations elucidates a stepwise hydrogenation pathway: *NO₃ → *NO₂ → *NO → *NH₂OH → *NH₃, with the rate-determining step (RDS) identified as *NO hydrogenation to *NHO. The hierarchical porosity of the aerogel facilitates mass transport while Cu-Co synergy suppresses hydrogen evolution reactions <i>via</i> electronic modulation. Practical viability is demonstrated through stable 12 hour operation in a Zn-NO₃ ^- battery. This work provides insights into Cu-Co catalysis and establishes design principles for high-performance NO₃RR systems.2025-01-01T00:00:00Z2025 Oct2026-06-04T16:25:07.749Z2026-06-02T03:08:41.815ZS-EPMC124592864100011710.1039/d5sc04633e