物理化学学报 >> 2007, Vol. 23 >> Issue (06): 835-840.doi: 10.3866/PKU.WHXB20070608

研究论文 上一篇    下一篇

甲醇溶液辉光放电等离子体电解

严宗诚; 陈砺; 王红林   

  1. 华南理工大学化工与能源学院, 广东省绿色化学产品技术重点实验室, 广州 510640

  • 收稿日期:2006-11-10 修回日期:2006-12-29 发布日期:2007-06-04
  • 通讯作者: 严宗诚 E-mail:nevill_yan@126.com

Glow Discharge Plasma Electrolysis of Methanol Solutions

YAN Zong-Cheng; CHEN Li; WANG Hong-Lin   

  1. Guangdong Provincial Laboratory of Green Chemical Technology, School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510640, P. R. China

  • Received:2006-11-10 Revised:2006-12-29 Published:2007-06-04
  • Contact: YAN Zong-Cheng E-mail:nevill_yan@126.com

摘要:

甲醇溶液辉光放电等离子体电解过程出现明显的非法拉第定律现象, 主要产物是氢气和甲醛, 还有少量一氧化碳、甲烷、乙烷、丙烷、1,3,5-三噁烷和水等, 产物和产量受放电极性和辅助电解质及放电电压等因素的影响. 在甲醇溶液电导率为11.40 mS·cm-1, 放电电压700 V 条件下, 阳极气体产量为55.90 mol/(mol electrons), 阴极气体产量为707.90 mol/(mol electrons), 阴极气体产量是阳极气体产量的12.66 倍, 气相产物中氢气含量在86%(molar fraction)以上. 在等离子体层中甲醇分解过程和其它类型的等离子体分解过程类似, 蒸汽鞘层中的加速电子是引发辉光放电过程非法拉第定律现象的决定因素. 阴极辉光放电过程中等离子体-溶液界面上的主要活性物种是中性粒子和电子,阳极辉光放电过程中等离子体鄄溶液界面上的主要活性物种是中性粒子和正离子. 辅助电解质对产物的影响主要是通过影响界面上发生的后续反应过程来表现.

关键词: 甲醇, 辉光放电电解, 等离子体, 等离子体化学反应

Abstract:

Non-faradic phenomena were found during the glow discharge plasma electrolysis of methanol solution, and the main products of the reactions induced by the glow discharge plasmas were hydrogen, formaldehyde, monoxide, methane, ethane, propane, sym-trioxane, and water. The chemical yields were affected by the polarity of the glow discharge plasma and supporting electrolytes of the solutions. The gas yield of the anodic glow discharge electrolysis of methanol was 55.90 mol/(mol electrons) when the discharge voltage across the circuit was 700 V and the conductivity of the solution was 11.40 mS·cm-1. The gas yield of the cathodic glow discharge was 707.90 mol/(mol electrons), 12.66 times of the anodic glow discharge gas yield, under the same conditions. The hydrogen concentration in the emission gas of the glow discharge electrolysis was higher than 86% (molar fraction). The decomposition of methanol molecules induced by the glow discharge plasmas around discharge electrode was similar to those induced by corona plasmas and dielectric discharge plasmas. Non-faradic phenomena of the glow discharge electrolysis of the methanol solutions were stirred up by the accelerated electrons within the gas sheath around the discharge electrode. Neutral species and electrons excited the methanol molecules on the plasma-electrolyte interface during cathodic glow discharge, while positive ions and neutral species played a more important role to excite the methanol molecules on the plasma-electrolyte interface during anodic glow discharge. The reactions in the liquid phase near the plasma-solution interface were affected by the supporting electrolytes of the solutions.

Key words: Methanol, Glow discharge electrolysis, Plasma, Plasma chemical reaction

MSC2000: 

  • O646.9