In situ fourier transform infrared (FTIR) study of nonthermal-plasma-assisted methane oxidative conversion
In situ fourier transform infrared (FTIR) study of nonthermal-plasma-assisted methane oxidative conversion
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DOI：
10.1021/ie0606688
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发表时间：
2007-05-23
影响因子：
4.2
通讯作者：
Okazaki, Ken
中科院分区：
文献类型：
--
作者：
Nair, S. A.;Nozaki, Tomohiro;Okazaki, Ken
非热等离子体辅助甲烷转化作为一种潜在的低温过程已被广泛研究。期望的最终目标是合成气生产，一步生产液态氧，或偶联产品。氧或蒸汽或两者都被用作第二反应物或反应物，以提供额外的O原子并启动等离子体辅助自由基处理。本文旨在研究等离子体加工过程中形成的各种可能的产物/反应物质。采用原位傅立叶变换红外（FTIR）吸收光谱法监测产物/反应基团。实验在室温和低能量输入（50 kJ/(mol CH4)）下，在CH4/O-2/N-2/H2O（大气湿度）的气体混合物中进行。在无氧条件下，生成烷烃、烯烃和炔烃基团，表示终止反应。随着氧浓度的增加（11,15,33 %），观察到烷烃逐渐转变为-CHO基团。此外，在氧气输入的情况下，可以检测到醇基的形成，这表明CH4解离产物与O自由基之间的耦合是第一步。研究了高能量输入和催化表面（如铂）存在的影响。
Nonthermal plasma-assisted methane conversion has been widely investigated as a potential low-temperature process. The desired end objective is synthesis gas production, one-step production of liquid oxygenates, or coupling products. Either oxygen or steam or both is used as a second reactant or reactants, to provide additional O atoms and initiate plasma-assisted radical processing. The present paper intends to investigate the various possible products/reactive species that are formed during plasma processing. In situ Fourier transform infrared (FTIR) absorption spectrometry is used to monitor the products/reactive groups. Experiments are performed at room temperature and at low energy inputs (50 kJ/(mol CH4)) in a gas mixture of CH4/O-2/N-2/H2O (atmospheric humidity). In the absence of oxygen, alkane, alkene, and alkyne groups are formed as the products, which indicates termination reactions. With increasing oxygen concentration (11, 15, and 33%) a gradual shift from alkane to a -CHO group is observed. In addition, alcohol group formation is detected with oxygen input, which indicates coupling between the CH4 dissociation products and the O radicals as a primary step. The effect of higher energy input and the presence of catalytic surfaces such as platinum also are investigated.