环境条件下一步尿素合成的电催化C–N偶联是传统尿素合成方案的有希望的替代方案。然而，中间物种的氢化阻碍了尿素的高效合成。
该文中，富氧空位CeO2被证明是一种高效的电催化剂，其通过插入空位使关键中间体*NO稳定，这有利于随后的C–N偶联过程而不是质子化，而在空位不足的催化剂上观察到C–N与质子化偶联的选择性差。通过原位和频发生谱对氧空位介导的选择性C–N偶联进行了区分和验证。氧空位的引入使普通催化剂载体成为高效电催化剂，尿素产率高达943.6 mg h–1 g–1，优于部分贵金属基电催化剂。
该项工作为耦合系统的催化剂设计和开发提供了新的见解。
附：英文原文
Title: Oxygen Vacancy-Mediated Selective C–N Coupling toward Electrocatalytic Urea Synthesis
Author: Xiaoxiao Wei, Xiaojian Wen, Yingying Liu, Chen Chen, Chao Xie, Dongdong Wang, Mengyi Qiu, Nihan He, Peng Zhou, Wei Chen, Jun Cheng, Hongzhen Lin, Jianfeng Jia, Xian-Zhu Fu, Shuangyin Wang
Issue&Volume: June 24, 2022
Abstract: The electrocatalytic C–N coupling for one-step urea synthesis under ambient conditions serves as the promising alternative to the traditional urea synthetic protocol. However, the hydrogenation of intermediate species hinders the efficient urea synthesis. Herein, the oxygen vacancy-enriched CeO2 was demonstrated as the efficient electrocatalyst with the stabilization of the crucial intermediate of *NO via inserting into vacant sites, which is conducive to the subsequent C–N coupling process rather than protonation, whereas the poor selectivity of C–N coupling with protonation was observed on the vacancy-deficient catalyst. The oxygen vacancy-mediated selective C–N coupling was distinguished and validated by the in situ sum frequency generation spectroscopy. The introduction of oxygen vacancies tailors the common catalyst carrier into an efficient electrocatalyst with a high urea yield rate of 943.6 mg h–1 g–1, superior than that of partial noble-metal-based electrocatalysts. This work provides novel insights into the catalyst design and developments of coupling systems.
DOI: 10.1021/jacs.2c03452
Source: https://pubs.acs.org/doi/10.1021/jacs.2c03452
