Clarke Russell J, Hicks Jason C
Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States.
ACS Eng Au. 2022 Dec 21;2(6):535-546. doi: 10.1021/acsengineeringau.2c00026. Epub 2022 Aug 5.
Plasma-surface coupling has emerged as a promising approach to perform chemical transformations under mild conditions that are otherwise difficult or impossible thermally. However, a few examples of inexpensive and accessible / techniques exist for observing plasma-solid interactions, which has prevented a thorough understanding of underlying surface mechanisms. Here, we provide a simple and adaptable design for a dielectric barrier discharge (DBD) plasma cell capable of interfacing with Fourier transform infrared spectroscopy (FTIR), optical emission spectroscopy (OES), and mass spectrometry (MS) to simultaneously characterize the surface, the plasma phase, and the gas phase, respectively. The system was demonstrated using two example applications: (1) plasma oxidation of primary amine functionalized SBA-15 and (2) catalytic low temperature nitrogen oxidation. The results from application (1) provided direct evidence of a 1% O/He plasma interacting with the aminosilica surface by selective oxidation of the amino groups to nitro groups without altering the alkyl tether. Application (2) was used to detect the evolution of NO species bound to both platinum and silica surfaces under plasma stimulation. Together, the experimental results showcase the breadth of possible applications for this device and confirm its potential as an essential tool for conducting research on plasma-surface coupling.
等离子体-表面耦合已成为一种很有前景的方法,可在温和条件下实现化学转化,而这些转化在热条件下很难或无法实现。然而,用于观察等离子体-固体相互作用的廉价且易于使用的技术实例很少,这妨碍了对潜在表面机制的深入理解。在此,我们提供了一种简单且适应性强的介质阻挡放电(DBD)等离子体池设计,该等离子体池能够与傅里叶变换红外光谱(FTIR)、光发射光谱(OES)和质谱(MS)连接,分别同时表征表面、等离子体相和气相。该系统通过两个示例应用进行了演示:(1)伯胺官能化SBA-15的等离子体氧化和(2)催化低温氮氧化。应用(1)的结果提供了直接证据,证明1% O/He等离子体通过将氨基选择性氧化为硝基而不改变烷基连接基与氨基二氧化硅表面相互作用。应用(2)用于检测在等离子体刺激下与铂和二氧化硅表面结合的NO物种的演变。总之,实验结果展示了该装置可能的应用范围,并证实了其作为研究等离子体-表面耦合的重要工具的潜力。