Direct Preparation of Hydrogen and Carbon Nanotubes by Microwave Plasma Decomposition of Methane over Fe/Si Activated by Biased Hydrogen Plasma

• 作者: Kaoru Onoe Katsuya Konno Tatsuaki Yamaguchi Yasuyuki Takiguchi
• 来源期刊: 绿色与可持续化学(英文)
• 学科: 化学
• 关键词: HYDROGEN METHANE DECOMPOSITION Carbon NANOTUBES Microwave PLASMA METHANE H2 PLASMA Treatment
• 年，卷（期）: 2013,（1）
• 页码范围: 19-25
• 页数: 7页
• 分类号: O6

摘要

Methane was decomposed to hydrogen and carbon nanotubes (CNTs) by microwave plasma, using Fe/Si catalyst activated by biased (—150 V) hydrogen plasma for various treatment times. Upon exposure to biased hydrogen plasma, the catalyst surface becomes lumpy within 1 min, coheres between 5 and 10 min and forms particles after 20 min. The methane conversion increased up to 93% over the treatment time of 5 min. The hydrogen yield showed as similar tendency as the methane conversion and kept 83% at treatment time of 5 min. The treatment time up to 1 min increased the amount of deposited carbon, and after treatment time of 5 min it dropped;then again after treatment time of 20 min, it increased to reach a maximum value of 22 gc/gcat. Deposited carbon was found to be consisted of carbon nanotubes. It grew vertically on the catalyst surface and reached a maximum length of 30.7 nm after treatment time of 10 min. Multiple types of CNTs were present, and the CNT diameters decreased with increasing plasma treatment time.