Electrocatalytic Reduction of Nitrate/Nitrite to Ammonia on CuCo Nanoparticles Decorated N‐doped Carbon

Abstract Electrocatalytic nitrate (NO ₃ ⁻ )/nitrite (NO ₂ ⁻ ) reduction of ammonia (NH ₃ ) provides energy‐saving and sustainable methods for NH ₃ synthesis. However, both reactions involve multiple electrons and multiple protons, making the reaction process complex with many by‐products. Thus, efficient catalysts are needed to improve the selectivity and yield of ammonia. Herein, the CuCo nanoparticles decorated N‐doped carbon (CuCo‐NC) derived from zeolitic imidazolate framework (ZIF) with a cross‐shaped leaf structure has been synthesized as electrocatalysts for NO ₃ ⁻ / NO ₂ ⁻ reduction. The obtained CuCo‐NC possesses Cu‐doped Co metallic nanoparticles, and hierarchical structure, and demonstrated to exhibit good activity and selectivity in electrocatalytic NO ₃ ⁻ /NO ₂ ⁻ reduction to NH ₃ synthesis. In the electrocatalytic NO ₃ ⁻ reduction of NH ₃ , the Faraday efficiency of NH ₃ reached 97% and the yield reached 7.17 mg h ⁻¹ cm ⁻² at −0.3 V. In the electrocatalytic NO ₂ ⁻ reduction of NH ₃ , the Faraday efficiency of NH ₃ reached 92% and the yield reached 8.34 mg h ⁻¹ cm ⁻² at −0.3 V, demonstrating good stability in the cyclic electrolysis of both reactions. The CuCo‐NC with a cross‐shaped leaf structure exhibits excellent electrocatalytic NO ₃ ⁻ /NO ₂ ⁻ reduction activity of CuCo‐NC and therefore highlights the promising potential of bimetallic electrocatalysts for NH ₃ synthesis.