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–NH 3 battery based on temporally decoupled ammonia splitting to achieve efficient NH 3 -to-H 2 conversion. In this system, ammonia is oxidized into nitrogen during cathodic charging (2NH 3 + 6OH – → N 2 + 6H 2 O + 6e – ) with external electrical energy conversion and storage, while during cathodic discharging, water is reduced to hydrogen (2H 2 O + 2e – → H 2 + 2OH – ) with electrical energy generation. In this loop, continuous and efficient H 2 production without separation and purification is achieved. With the help of the ammonia oxidation reaction (AOR) and hydrogen evolution reaction (HER) bifunctional catalyst of Mo 2 C/NiCu@C, a rechargeable Zn–NH 3 battery is realized that exhibits a high NH 3 -to-H 2 FE of 91.6% with outstanding durability for 900 cycles (300 h) at 20 mA/cm 2, enabling efficient and continuous NH 3 -to-H 2 conversion.