Zhu Changyan, Wen Chaoxia, Wang Miao, Zhang Min, Geng Yun, Su Zhongmin
Institute of Functional Material Chemistry, Faculty of Chemistry, National & Local United Engineering Laboratory for Power Batteries, Northeast Normal University Changchun 130024 China
School of Chemistry and Environmental Engineering, Changchun University of Science and Technology Changchun 130022 China.
Chem Sci. 2021 Dec 24;13(5):1342-1354. doi: 10.1039/d1sc04845g. eCollection 2022 Feb 2.
An electrocatalytic C-N coupling reaction to convert CO and N into urea under mild conditions has been proposed to be a promising alternative experimentally, but the development of highly stable, low-cost and high-performance non-metal catalytic sites remains rare and challenging. Herein, a global-minimum CuB monolayer with superior stability has been identified based on first-principles computations, and the most significant finding is that the CuB monolayer possesses the best catalytic activity among the reported urea catalysts thermodynamically and kinetically. All possible reaction pathways to form urea (NHCONH) starting from the CO molecule and N molecule, including the CO pathway, OCOH pathway, CO pathway, NCON pathway and mixed pathway, as well as the kinetic energy barriers of six possible C-N coupling reactions are systematically investigated. Non-metal B atoms at the midpoint of the edges of the squares act as excellent catalytic sites with a limiting potential of urea production of 0.23 V through the CO pathway and OCOH pathway and the lowest kinetic energy barrier of C-N bond formation (0.54 eV) through the reaction *CO + *NHNH → *NHCONH. Therefore, this study not only identifies the first non-metal B catalytic sites for urea formation, but also perfects the reaction mechanism to convert CO and N into urea, which could provide great guiding significance to explore other high-performance urea catalysts.
在温和条件下将一氧化碳和氮气转化为尿素的电催化碳氮偶联反应在实验上被认为是一种很有前景的替代方法，但开发高度稳定、低成本且高性能的非金属催化位点仍然罕见且具有挑战性。在此，基于第一性原理计算确定了一种具有卓越稳定性的全局最小CuB单层，最重要的发现是，CuB单层在热力学和动力学方面在所报道的尿素催化剂中具有最佳催化活性。系统地研究了从一氧化碳分子和氮分子开始形成尿素（NHCONH）的所有可能反应途径，包括CO途径、OCOH途径、CO途径、NCON途径和混合途径，以及六种可能的碳氮偶联反应的动能垒。正方形边缘中点处的非金属硼原子作为优异的催化位点，通过CO途径和OCOH途径产生尿素的极限电位为0.23 V，并且通过反应*CO + *NHNH → *NHCONH形成碳氮键的动能垒最低（0.54 eV）。因此，本研究不仅确定了首个用于尿素形成的非金属硼催化位点，还完善了将一氧化碳和氮气转化为尿素的反应机理，这可为探索其他高性能尿素催化剂提供重要的指导意义。
