Gram‐level NH₃ Electrosynthesis via NO_x reduction on a Cu Activated Co Electrode

Abstract

Ambient electrochemical ammonia (NH3) synthesis is one promising alternative to the energy‐intensive Haber‐Bosch route. However, the industrial requirement for the electrochemical NH3 production with amperes current densities or gram‐level NH3 yield remains a grand challenge. Herein, we report the high‐rate NH3 production via NO3‐ and NO2‐ reduction using the Cu activated Co electrode in a bipolar membrane (BPM) assemble electrolyser, wherein BPM maintains the ion balance and the liquid level of electrolyte. Benefited from the abundant activated Co sites and optimal structure, the target CuCo electrode delivers a current density of 2.64 A cm‐2 with the Faradaic efficiency of 96.45% and the high NH3 yield rate of 279.44 mg h‐1 cm‐2 in H‐type cell using alkaline electrolyte. Combined with in‐situ experiments and theoretical calculations, we found that Cu optimizes the adsorption behavior of NO2‐ and facilitates the hydrogenation steps on Co sites toward a rapid NO2‐ reduction process. Importantly, this activated Co electrode affords a large NH3 production up to 4.11 g h‐1 in a homemade reactor, highlighting its large‐scale practical feasibility.

Crystallinity regulation-induced organic degradation on ultra-thin 2D Co3O4/SiO2 nanosheets: the critical trigger of oxygen vacancies

“…The XPS spectra of Co 2p 3/2 in hemi-Co 3 O 4 /SiO 2 showed peaks at 780.53 eV and 782.32 eV, indicating the co-existence of Co 3+ and Co 2+ ions. 42 The Co 2+ /Co 3+ ratios of hemi-Co 3 O 4 /SiO 2 , A-Co 3 O 4 /SiO 2 and C-Co 3 O 4 /SiO 2 were 0.939, 0.815 and 0.698, respectively (Fig. 2a and Table S5†).…”

Recent research progress on building C–N bonds via electrochemical NOx reduction

“…The state-of-the-arts NO x RR systems can produce NH 3 with ∼90% FE at ∼1 A cm −2 . [31][32][33][34] Although NH 3 is a very important chemical building block, it is still desirable to make nitrogen products via electrochemical NO x RR that bear higher economic values than NH 3 , such as organonitrogen compounds.…”

Construction of Microreactor-like Square-Hole Carbon Nitride Boosting Photocatalytic Nitrogen Fixation Activity

“…Moreover, ammonia (NH 3 ) holds significant importance in the fields of industry and agriculture, serving as a valuable product for various industrial applications. Due to its high energy density (4.3 kW h kg –1 ), high hydrogen weight content (17.8%), absence of carbon dioxide (CO 2 ) emission, and ease of transformation into a liquid (33 °C) for transportation, NH 3 has recently gained attention as a possible contender for a carbon-free hydrogen economy of the future. − The Haber–Bosch process currently used in industry to produce NH 3 makes extensive use of fossil fuels and the resulting greenhouse gas emissions, making it important to develop renewable and green methods. − Now, photocatalysis is a viable strategy for NH 3 synthesis at the laboratory scale since it uses solar energy to generate NH 3 directly from air and water, which is environmental friendly without CO 2 emissions. − The scientific community has lately made some convincing progress in establishing the possibility of photocatalytic nitrogen reduction to yield NH 3 . Prior to being realistically practicable, it must first be possible to develop and build an effective N 2 fixation system with better electron–hole separation, improved quantum efficiency, catalytic selectivity, and N 2 adsorption and activation. − …”