化学学报 ›› 2009, Vol. 67 ›› Issue (10): 1127-1133. 上一篇    下一篇

研究论文

mPAM/mCMC双极膜电解槽中MnO2电催化氧化制备甘油醛

蔡燕红 陈日耀 郑 曦 陈 晓 陈 震*

  

  1. (福建师范大学化学与材料学院 福州 350007)

  • 投稿日期:2008-06-26 修回日期:2008-10-16 发布日期:2009-05-28
  • 通讯作者: 陈震

Preparation of Glyceraldehyde by MnO2 Electro-catalytic Oxidation in mPAM/mCMC BPM Equipped Cell

Cai, Yanhong Chen, Riyao Zheng, Xi Chen, Xiao Chen, Zhen*   

  1. (College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007)
  • Received:2008-06-26 Revised:2008-10-16 Published:2009-05-28
  • Contact: Chen, Zhen

分别以FeCl3和戊二醛等对羧甲基纤维素(CMC)和聚丙烯酰胺(PAM)进行改性, 制备了mPAM/mCMC双极膜. 测定了PAM、CMC胶体的电荷密度, mPAM/mCMC双极膜离子交换能力、I-V工作曲线等参数. 用扫描电镜和红外光谱对膜形貌与成分作表征, 膜厚≈260 μm, 中间界面层厚为纳米级. 热重分析表明膜具有较好的热稳定性. 以mPAM/mCMC双极膜为电解槽的隔膜, 间接电氧化甘油为甘油醛. 在电场的作用下, 双极膜中间层中的水离解产生H+和OH−, OH−及时地传输入阳极室, 中和了电生成甘油醛时生成的H+, 促进了正向反应的进行. 槽电压稳定, 产率达91.6%, 电流效率为65.5%.

关键词: 双极膜, 聚丙烯酰胺, 羧甲基纤维素, 甘油醛, 电催化氧化, 纳米MnO2

Modified PAM/CMC bipolar membrane was prepared after carboxymethyl cellulose (CMC) and polyacrylamide (PAM) were cross-linked by Fe3+and glutaraldehyde, respectively. Meanwhile the ion exchange capacity and the I-V curves of the bipolar membrane as well as its co-ion transport properties were investigated. SEM photographs show that the mPAM/mCMC bipolar membrane consists of the anion layer (mPAM) and the cation layer (mCMC) with a clear interface. FTIR was applied to analyse the function group in the bipolar membrane. Furthermore, TG result exhibited a good thermal stability. The mPAM/mCMC bipolar membrane was used as a separator in the electrolysis cell for electro-generation of glyceraldehyde by using MnO2/Mn2+as a medium in a supersonic wave bath. The electro-generated nanometer MnO2 was dispersed in the solution and used for the selective oxidation of glycerine to glyceraldehyde. Under the function of electric field, the water in the bipolar membrane (BPM) was dissociated to produce H+and OH-. OH- migrates in the anode chamber to neutralize H+, which promotes the positive reaction process by eliminating the accumulation of H+. The yield was 91.6% and the current of efficiency reached 65.5%.

Key words: bipolar membrane, polyacrylamide, carboxymethyl cellulose, glyceraldehyde, electro-catalytic oxidation, nanometer MnO2