Electrifying the nitrogen loop: atomically dispersed catalysts for nitrate-to-ammonia conversion, from navigating the reaction landscape to integrating system design

Electrifying the nitrogen loop via electrocatalytic nitrate reduction to ammonia (e RR-to-NH 3 ) offers a paradigm shift towards a sustainable nitrogen economy, simultaneously remediating nitrate pollution and producing valuable ammonia. The complex reaction landscape of e RR-to-NH 3 , however, demands catalysts with exceptional precision. Atomically dispersed catalysts (ADCs) have emerged as key enablers, offering well-defined active sites to navigate and manipulate the reaction pathway. This review comprehensively charts the progress of ADCs, bridging the gap from fundamental mechanistic insights to integrated system design. We begin by exploring how precise structural control over ADCs—through coordination engineering, support effects, microenvironment regulation, electronic structure engineering, and external magnetic field regulation—enables the deciphering of reaction mechanisms and the enhancement of catalytic performance. Advanced in situ characterization and theoretical simulations are highlighted as critical tools for navigating the reaction landscape at the atomic level. Furthermore, we extend the discussion beyond the catalyst itself to the challenges of integrating system design, including techno-economic analysis, coupled reaction processes, and scalable reactor engineering. Finally, we outline future frontiers in machine learning and reactor optimization, providing a roadmap for translating atomic-level precision into practical, circular nitrogen management systems.