Li Weihang, Jiang Haoyang, Zhang Xiang, Lei Bo, Li Le, Zhou Haoshen, Zhong Miao
College of Engineering and Applied Sciences, Collaborative Innovation Centre of Advanced Microstructures, National Laboratory of Solid State Microstructures, Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, 163 Xianlin Avenue, Qixia District, Nanjing 210023, China.
J Am Chem Soc. 2024 Aug 7;146(31):21968-21976. doi: 10.1021/jacs.4c07142. Epub 2024 Jul 25.
Electrified synthesis of high-value organonitrogen chemicals from low-cost carbon- and nitrogen-based feedstocks offers an economically and environmentally appealing alternative to traditional thermocatalytic methods. However, the intricate electrochemical reactions at electrode surfaces pose significant challenges in controlling selectivity and activity, especially for producing complex substances such as -dimethylformamide (DMF). Herein, we tackle this challenge by developing relay catalysis for efficient DMF production using a composite WO-NiOOH/Ni catalyst with two distinctive active sites. Specifically, WO selectively promotes dimethylamine (DMA) electrooxidation to produce strongly surface-bound (CH)N*, while nearby NiOOH facilitates methanol electrooxidation to yield more weakly bound *CHO. The disparity in binding energetics of the key C- and N-intermediates expedites C-N coupling at the WO-NiOOH interface. infrared spectroscopy with isotope-labeling experiments, quasi- electron paramagnetic resonance trapping experiments, and electrochemical operating experiments revealed the C-N coupling mechanism and enhanced DMF-synthesis selectivity and activity. X-ray absorption spectroscopy (XAS) and postreaction transmission electron microscopy (TEM) studies verified the stability of WO-NiOOH/Ni during extended electrochemical operation. A Faradaic efficiency of ∼50% and a production rate of 438 μmol cm h were achieved at an industrially relevant current density of 100 mA cm over an 80 h DMF production period. This study introduces a new paradigm for developing electrothermo relay catalysis for the sustainable and efficient synthesis of valuable organic chemicals with industrial potential.
从低成本的碳基和氮基原料出发，通过电合成制备高价值有机氮化学品，为传统热催化方法提供了一种经济且环保的替代方案。然而，电极表面复杂的电化学反应在控制选择性和活性方面带来了重大挑战，特别是在生产诸如二甲基甲酰胺（DMF）等复杂物质时。在此，我们通过开发一种具有两个独特活性位点的复合WO-NiOOH/Ni催化剂的接力催化来应对这一挑战，以实现高效的DMF生产。具体而言，WO选择性地促进二甲胺（DMA）的电氧化，生成强表面结合的(CH)N*，而附近的NiOOH则促进甲醇的电氧化，产生结合较弱的*CHO。关键的C-和N-中间体结合能的差异加速了WO-NiOOH界面处的C-N偶联。同位素标记实验的红外光谱、准电子顺磁共振捕获实验以及电化学操作实验揭示了C-N偶联机制，并提高了DMF合成的选择性和活性。X射线吸收光谱（XAS）和反应后透射电子显微镜（TEM）研究验证了WO-NiOOH/Ni在长时间电化学操作过程中的稳定性。在80小时的DMF生产期间，在100 mA cm的工业相关电流密度下，法拉第效率约为50%，生产率为438 μmol cm h。本研究引入了一种新的范式，用于开发电热接力催化，以可持续且高效地合成具有工业潜力的有价值有机化学品。
