H Kapsamının Hafif Oksidanlarla Düzenlenmesi, Düşük İletkenlikli Ortamlarda Elektrokatalitik Nitratın N2'ye İndirgenmesini Teşvik Eder

Özet (abstract)

Abstract Electrocatalytic nitrate reduction reaction (NO3RR) has attracted growing interest for converting nitrate (NO3–) into ammonium (NH4+), yet NH4+ production from dilute, low-conductivity waters is constrained by high energy consumption, limited NO3– availability, and costly product recovery. Steering NO3RR directly toward benign N2 therefore represents a more practical route, but this pathway is often suppressed by excessive surface *H coverage, which drives the overhydrogenation of nitrogen intermediates to NH4+. Here, we report a mild oxidant-assisted coelectrolysis strategy that regulates interfacial *H coverage and promotes NO3–-to-N2 conversion in a Cu nanoparticle-decorated Ni cathode membrane electrochemical reactor. This reactor separates a highly conductive electrochemical chamber from a NO3–-containing chemical chamber, enabling NO3– reduction in low-conductivity media while maintaining a less negative cathodic potential. Mild oxidants, including H2O2, O2, CH3COOOH, and KIO4, consumed excess *H and redirected the reaction pathway toward N–N coupling. With H2O2 as a representative oxidant, N2 selectivity increased from 13.47% without H2O2 to 87.25% at 100 mM H2O2. Mechanistic analyses revealed that H2O2 decreases interfacial *H abundance, which suppresses NH4+ formation and facilitates the dimerization of nitrogen-containing intermediates. Verification in real low-conductivity groundwater further supports this strategy as a mechanistic basis for designing selective, low-energy electrochemical denitrification systems for low-conductivity NO3–-contaminated media.

Yazarların özeti; kaynağından alınmıştır. Environmental Science & Technology, 2026 · DOI ↗