Reversing the Hydrogenation Pathways of Nitrogen‐Containing Intermediates for the Kinetics‐Matched Urea Electrosynthesis

Abstract

ABSTRACT Urea electrosynthesis from carbon dioxide (CO 2 ) and nitrate (NO 3 − ) is a promising sustainable route. However, the kinetic mismatch between key intermediates remains the major challenge for achieving selective C‒N coupling. Herein, indium‐doped titanium dioxide (In‐TiO 2 ) nanofibers were developed to regulate the hydrogenation pathway for realizing kinetics‐matched urea electrosynthesis. In situ spectroscopic analysis and theoretical calculations reveal that In doping reverses the hydrogenation pathway of nitrogen‐containing intermediates from the Eley‐Rideal (E‐R) to the Langmuir–Hinshelwood (L–H) mechanism. This shift is attributed to the sufficient *H supply guaranteed by the regulated interfacial water structure. Such reversed hydrogenation pathway balances *H utilization between CO 2 and NO 3 − reduction, enabling well‐matched formation kinetics of key intermediates for efficient C‒N coupling. Owing to the above merits, In‐TiO 2 achieved the remarkable average urea yield rate of 56.5 mmol h −1 g −1 with a Faradaic efficiency of 32.8%. This work provides mechanistic insights into the hydrogenation pathways regulation for efficient urea electrosynthesis.