Li Zhenlu, Liu Shize, Zhan Qingyun, Li Jiayang, Zhang Zihao, Qian Yumeng, Cai Yiyu, Mu Xiaoyue, Li Lu
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
School of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot, 010051, P. R. China.
Angew Chem Int Ed Engl. 2025 Mar 17;64(12):e202424165. doi: 10.1002/anie.202424165. Epub 2025 Jan 9.
Green ammonia synthesis using fluctuating renewable energy supply in decentralized process is a goal that has been long sought after. Ammonia synthesis with non-thermal plasma under mild conditions is a promising technology, but it faces the critical challenge of low energy efficiency. Herein, we develop an easily-scalable AuCu/Cu catalyst, which consists of a decimeter-scale metallic Cu antenna and nano-scale AuCu catalytic sites on metallic Cu surface, significantly enhancing the energy efficiency and ammonia yield in a radio-frequency (RF) plasma system. Compared to plasma alone, the single-pass ammonia yield over AuCu/Cu increases by a factor of 20, approaching 10 %. Mechanistic studies indicate that Cu antenna can amplify the millimeter-scale local electric field, thereby facilitating the generation of active nitrogen species, including nitrogen radicals and vibration-excited nitrogen molecules. Due to the downshifted d-band center and unique Cu-Au interface structure, the AuCu nanoalloy modified on Cu antenna surface significantly reduces hydrogenation barriers of active NH (x=0,1,2) species (the rate-determining step) and facilitates ammonia desorption at lower temperature. The synergistic effect of Cu antenna and surface AuCu nanoalloy comprehensively enhances ammonia synthesis through both the nitrogen radical-mediated Eley-Rideal pathway and the vibration-excited nitrogen molecule-mediated Langmuir-Hinshelwood pathway.
在分散式过程中利用波动的可再生能源供应进行绿色氨合成是一个长期追求的目标。在温和条件下利用非热等离子体进行氨合成是一项很有前景的技术，但它面临着能源效率低的关键挑战。在此，我们开发了一种易于扩展的AuCu/Cu催化剂，它由分米级金属铜天线和金属铜表面的纳米级AuCu催化位点组成，显著提高了射频（RF）等离子体系统中的能源效率和氨产量。与单独的等离子体相比，AuCu/Cu上的单程氨产量提高了20倍，接近10%。机理研究表明，铜天线可以放大毫米级的局部电场，从而促进活性氮物种的产生，包括氮自由基和振动激发的氮分子。由于d带中心下移和独特的Cu-Au界面结构，修饰在铜天线表面的AuCu纳米合金显著降低了活性NH（x=0,1,2）物种氢化的势垒（速率决定步骤），并促进了较低温度下氨的解吸。铜天线和表面AuCu纳米合金的协同效应通过氮自由基介导的Eley-Rideal途径和振动激发的氮分子介导的Langmuir-Hinshelwood途径全面增强了氨合成。
