Authors: Zhengyi Li, Yan Zhang, Hu Li, Ming Zhou, Jinyan Liang, Yaqiong Su, Xihong Lu, Song Yang
Published: 2025-05-14
Source: Full article
AbstractThe green urea synthesis via co‐electrolysis of waste nitrate and CO2 is alluring but challenging, especially with insufficient selectivity caused by thermodynamic differences and kinetic mismatch between multi‐step conversion processes. Here, a domino effect‐oriented electrosynthesis strategy is showcased to steer cascade reactions in upgrading nitrate and CO2 toward urea of high selectivity on Bi‐doped In2O3 with asymmetric oxygen vacancies (Ov). The conventionally arbitrary reaction mode can be vectored and re‐customized by stable and cumulative *NH2 intermediates in situ derived from priority nitrate reduction reaction, which not only form surface frustrated Lewis pairs (SFLPs, Bi─Ov─In─NH2) with Bi Lewis acid sites to synergistically adsorb and activate CO2 but also provide more opportunities for sluggish C─N coupling, delivering an unprecedented urea Faradic efficiency of 80.2% and an impressive urea yield of 2.38 × 103 µg h−1 mgcat.−1 at −0.4 V versus RHE. The atomically dispersed Bi sites promote the protonation of *NO to form nucleophilic *NH2 intermediates, which can be stabilized in the electrophilic region mediated by asymmetric Ov, permitting two nucleophilic attacks to complete the C─N coupling. The domino modeling protocol via positioning a specific intermediate in situ tailors the parallel conversion process and may guide selectivity control of electrosynthesis.