Wang Canhui, Yang Wei-Chang D, Raciti David, Bruma Alina, Marx Ronald, Agrawal Amit, Sharma Renu
Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.
Institute for Research in Electronics and Applied Physics, and Maryland NanoCenter, University of Maryland, College Park, MD, USA.
Nat Mater. 2021 Mar;20(3):346-352. doi: 10.1038/s41563-020-00851-x. Epub 2020 Nov 2.
Metallic nanoparticles have been used to harvest energy from a light source and transfer it to adsorbed gas molecules, which results in a reduced chemical reaction temperature. However, most reported reactions, such as ethylene epoxidation, ammonia decomposition and H-D bond formation are exothermic, and only H-D bond formation has been achieved at room temperature. These reactions require low activation energies (<2 eV), which are readily attained using visible-frequency localized surface plasmons (from ~1.75 eV to ~3.1 eV). Here, we show that endothermic reactions that require higher activation energy (>3.1 eV) can be initiated at room temperature by using localized surface plasmons in the deep-UV range. As an example, by leveraging simultaneous excitation of multiple localized surface plasmon modes of Al nanoparticles by using high-energy electrons, we initiate the reduction of CO to CO by carbon at room temperature. We employ an environmental transmission electron microscope to excite and characterize Al localized surface plasmon resonances, and simultaneously measure the spatial distribution of carbon gasification near the nanoparticles in a CO environment. This approach opens a path towards exploring other industrially relevant chemical processes that are initiated by plasmonic fields at room temperature.
金属纳米颗粒已被用于从光源收集能量并将其转移到吸附的气体分子上，这导致化学反应温度降低。然而，大多数报道的反应，如乙烯环氧化、氨分解和H-D键形成都是放热反应，并且仅在室温下实现了H-D键的形成。这些反应需要较低的活化能（<2 eV），使用可见光频率的局域表面等离子体激元（约1.75 eV至约3.1 eV）很容易达到。在这里，我们表明，通过使用深紫外范围内的局域表面等离子体激元，可以在室温下引发需要更高活化能（>3.1 eV）的吸热反应。例如，通过利用高能电子同时激发铝纳米颗粒的多个局域表面等离子体激元模式，我们在室温下引发了碳将CO还原为CO的反应。我们使用环境透射电子显微镜来激发和表征铝的局域表面等离子体激元共振，并同时测量在CO环境中纳米颗粒附近碳气化的空间分布。这种方法为探索其他在室温下由等离子体激元场引发的工业相关化学过程开辟了一条道路。
