吉林大学李路团队报道了AuCu₃/Cu复合催化剂对等离子体驱动氨合成的协同增强作用。相关研究成果发表在2024年12月23日出版的国际知名学术期刊《德国应用化学》。

在分散过程中使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。温和条件下低温等离子体合成氨是一种有前景的技术，但它面临着低能效的关键挑战。

该文中，研究人员开发了一种易于扩展的AuCu₃/Cu催化剂，该催化剂由分米级金属Cu天线和金属Cu表面上的纳米级AuCu₃催化位点组成，显著提高了射频（RF）等离子体系统的能量效率和氨产量。与单独使用等离子体相比，AuCu₃/Cu的单程氨产量增加了20倍，接近10%。

机理研究表明，铜天线可以放大毫米级局部电场，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带中心的下移和独特的Cu-Au界面结构，在Cu天线表面改性的AuCu₃纳米合金，显著降低了活性NHX（x=0,1,2）物种的氢化势垒（速率决定步骤），并促进了氨在较低温度下的解吸。

Cu天线和表面AuCu₃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，全面增强了氨的合成。

附：英文原文

Title: Synergistic Enhancement of Plasma-Driven Ammonia Synthesis Using a AuCu3/Cu Composite Catalyst

Author: Zhenlu Li, Shize Liu, Qingyun Zhan, Jiayang Li, Zihao Zhang, Yumeng Qian, Yiyu Cai, Xiaoyue Mu, Lu Li

Issue&Volume: 2024-12-23

Abstract: 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 AuCu3/Cu catalyst, which consists of a decimeter-scale metallic Cu antenna and nano-scale AuCu3 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 AuCu3/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 AuCu3 nanoalloy modified on Cu antenna surface significantly reduces hydrogenation barriers of active NHX (x=0,1,2) species (the rate-determining step) and facilitates ammonia desorption at lower temperature. The synergistic effect of Cu antenna and surface AuCu3 nanoalloy comprehensively enhances ammonia synthesis through both the nitrogen radical-mediated Eley-Rideal pathway and the vibration-excited nitrogen molecule-mediated Langmuir-Hinshelwood pathway.

DOI: 10.1002/anie.202424165

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202424165