Temporally Decoupled Ammonia Splitting by a Zn–NH3 Battery with an Ammonia Oxidation/Hydrogen Evolution Bifunctional Electrocatalyst as a Cathode

Ammonia splitting to hydrogen is a decisive route for hydrogen economy but is seriously limited by the complex device and low efficiency. Here, we design and propose a new rechargeable Zn-NH₃ battery based on temporally decoupled ammonia splitting to achieve efficient NH₃-to-H₂ conversion. In this system, ammonia is oxidized into nitrogen during cathodic charging (2NH₃ + 6OH^- → N₂ + 6H₂O + 6e^-) with external electrical energy conversion and storage, while during cathodic discharging, water is reduced to hydrogen (2H₂O + 2e^- → H₂ + 2OH^-) with electrical energy generation. In this loop, continuous and efficient H₂ production without separation and purification is achieved. With the help of the ammonia oxidation reaction (AOR) and hydrogen evolution reaction (HER) bifunctional catalyst of Mo₂C/NiCu@C, a rechargeable Zn-NH₃ battery is realized that exhibits a high NH₃-to-H₂ FE of 91.6% with outstanding durability for 900 cycles (300 h) at 20 mA/cm², enabling efficient and continuous NH₃-to-H₂ conversion.