Continuous Intermediates Spillover Boosts Electrochemical Nitrate Conversion to Ammonia over Dual Single-Atom Alloy

Electrochemical nitrate conversion to ammonia driven by sustainable green electricity is regarded as a promising supplement to the traditional Haber–Bosch process. However, it is still restricted by the low NH₃ yield rate and Faradaic efficiency. Here, we propose a continuous intermediates spillover strategy by constructing dual single-atom alloy to boost ammonia yield rate and Faradaic efficiency. The intermediates continuously spill over back and forth on the atomically dispersed Mo and Fe sites in Pd lattice, which adaptively experiences low energy barrier for each elementary step in nitrate conversion. As a result, the synthesized dual single-atom alloy metallene delivered an NH₃ yield rate of 13.4 mol g_cat.⁻¹ h⁻¹, and Faradaic efficiency of 94.6%, as well as remarkable cycling stability of 300 h. Furthermore, the dual single-atom alloy metallene was assembled into a zinc-nitrate battery as the cathode, which delivered an output voltage of 1.477 V, and the maximum output power density of 13.4 mW cm⁻².