【Frontiers in HaiChuan Technology】Dalian Institute of Chemical Physics achieves ammonia synthesis via high-activity and high-stability nitrate electrocatalytic reduction

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In January 2025, the Research Group on Electrocatalytic Conversion of Carbon-Based Resources (Group 523) at the **Key Laboratory of Catalysis Fundamentals** of Dalian Institute of Chemical Physics made new progress in the electrochemical synthesis of ammonia. An integrated amorphous/crystalline biphasic copper foam electrode was developed, and by stabilizing the metastable amorphous structure within the catalyst, long-term stable ammonia synthesis via electrocatalytic reduction of nitrates at ampere-level current densities was achieved. In industry, ammonia is typically synthesized using the Haber-Bosch process, in which nitrogen and hydrogen are converted into ammonia (NH3) at high temperatures (400°C to 500°C) and high pressures (10 MPa to 30 MPa). This process consumes approximately 1% to 2% of the world’s energy supply, and the carbon dioxide emitted as a result accounts for about 1% of global emissions. The nitrate electrocatalytic reduction reaction (NO3−RR) uses renewable electrical energy to convert NO3− pollutants in wastewater into ammonia, representing an important method for ammonia synthesis under mild conditions. The reduction of NO3− to NH3 involves multiple proton and electron transfer steps, has a slow kinetic rate, and is subject to competitive hydrogen evolution reactions as well as the formation of nitrite by-products. Therefore, there is an urgent need to develop NO3−RR ammonia synthesis catalysts with high activity, high selectivity, and high stability. In this work, the team treated commercial foam copper via air calcination to produce an integrated foam copper electrode (a/c-Cu) with a stable amorphous/crystalline biphasic structure, enabling long-term, stable, and efficient NO3−RR ammonia synthesis. At a voltage of only 2.6 V in the membrane electrode electrolyzer, the NH3 current density reached 3.33 A/cm2, and the NH3 generation rate reached 15.5 mmol/h/cm2. At a high current density of 1.5 A/cm2, the a/c-Cu electrode operated stably for over 300 hours, with the Faradaic efficiency of NH3 remaining at around 90%. Mechanistic studies such as electrochemical in-situ spectroscopic characterization and density functional theory calculations indicate that the amorphous Cu domains stably present in the a/c-Cu electrode are the primary catalytic active sites. The integrated electrode preparation method developed in this work is simple and easy to scale up, and its electrolytic performance is superior to that of traditional powder electrodes. Using an integrated copper foam electrode with an area of 100 cm2, the NH3 generation rate reached as high as 11.9 g/h at a total current of 160 A. The relevant research findings were published recently in Nature Communications under the title “Ammonia electrosynthesis from nitrate using a stable amorphous/crystalline dual-phase Cu catalyst”. A Chinese invention patent has been applied for for the electrode preparation method: “A biphasic copper foam electrode for the electrocatalytic reduction of nitrate to ammonia in membrane electrode systems, as well as its preparation method and applications”. The co-first authors of this work are Wang Yi, a doctoral student in Group 523 of my institute, and Wang Shuo, a postdoctoral researcher. The above work was supported by projects such as the **Key Research and Development Program**, the National Natural Science Foundation of China, the Class B Pilot Project of the Chinese Academy of Sciences titled “Dynamic Analysis and Intelligent Design of Energy Electrocatalysis”, the Liaoning Province Xingliao Talent Program, the Dalian City Outstanding Young Scientists Support Program, and the innovation fund of our institute.