Dynamic catalytic interface driven three-step synergistic mechanism for boosting ammonia and hydroxylamine synthesis

Despite the short-term industrial landscape remaining unchanged, green synthesis technologies for ammonia (NH 3 ) and hydroxylamine (NH 2 OH) are critical for carbon neutrality. Alternatively, electrocatalytic nitrate reduction (NIRR) can be integrated with membrane separation technology via a modular design, simultaneously achieving pollution control and resource recovery. However, the microscopic mechanism of NIRR remains ambiguous given the complex dynamic catalytic interface, hindering advanced catalyst development. Here, we propose a three-step synergistic mechanism at dynamic catalytic interface, which integrates interfacial microenvironment regulation, OH species cycle, and reverse hydrogen spillover for efficient NH 3 and NH 2 OH synthesis across different scenarios. Notably, dual-site heterostructure catalyst exhibits almost 100% NH 3 -Faradaic Efficiency (FE NH3 ) across a wide nitrate concentration range, reaching a maximum NH 3 yield of 10.27 mmol h −1 cm −2 . The simultaneous NH 3 synthesis-recovery system maintains almost 100% FE NH3 and NH 3 recovery efficiency over 120 h, accompanied by long-term durability and negligible performance degradation. Additionally, cyclopentanone-mediated NIRR process delivers a satisfactory NH 2 OH-Faradaic Efficiency (83.48%), and the assembled zinc-nitrate battery achieves a high peak power density (57.6 mW cm −2 ).