Dynamic pulse electrocatalysis for efficient and directed reduction of nitrate to ammonia

The electrochemical nitrate reduction reaction (NO₃RR) presents a sustainable pathway to simultaneously address environmental nitrate (NO₃⁻) pollution and decarbonize ammonia (NH₃) production. While traditional constant-potential electrocatalysis for NO₃RR has been widely studied, it suffers from inherent limitations, including competing hydrogen evolution, intermediate desorption, mass transfer bottlenecks, etc. In response, pulsed electrocatalysis, as an easily operable method, enables the regulation of reaction pathways by periodically varying applied potentials and can effectively overcome the limitations of constant-potential catalysis. However, research on pulsed catalysis in NO₃RR remains fragmented, lacking systematic categorization. Consequently, this review provides a comprehensive overview of pulsed NO₃RR systems, encompassing fundamental testing methodologies, catalytic mechanisms, device configurations, in situ characterization techniques, and merits of pulsed strategy. Furthermore, the analysis outlines essential criteria for catalyst design to maximize the potential of pulsed strategy and emphasizes the need for enhanced research and refined investigations in existing pulsed NO₃RR implementations.