Pulsed photoelectrocatalysis enables efficient urea synthesis over Cu(salen)-COF

Abstract Electrocatalytic urea synthesis from carbon dioxide and nitrate under ambient conditions offers a sustainable alternative to the energy-intensive Bosch-Meiser process. However, its efficiency is constrained by the spatiotemporal mismatch of key carbon and nitrogen intermediates at the catalyst-electrolyte interface. Herein, we address this limitation through interfacial microenvironment optimization combining ionic liquid modification of copper-salen covalent organic framework, pulsed electrolysis, and photoelectrocatalytic coupling. The ionic liquid modification enriches carbon dioxide and facilitates interfacial charge transfer, pulsed electrolysis promotes the dynamic matching of carbon and nitrogen intermediates, and photoelectrocatalytic coupling boosts interfacial electron accumulation. The integrated system achieves a urea yield rate of 69.2 mmol g cat −1 h −1 with a Faradaic efficiency of 56.7% in an H-type cell and 82.5% in a flow cell. In this work, we establish a generalizable strategy for efficient urea electrosynthesis via hierarchical interfacial control and highlight the potential of pulsed photoelectrocatalysis.