Electrode Processes Utilizing the Interlayer Space of Inorganic Molecular Aggregates a Reaction Zone

(1)研究了Ru(Bpy)^2+(bpy=2，2‘-联吡啶)和Fe(CN)^3-离子在粘土修饰电极上的氧化还原行为与溶液酸度的关系，发现随着溶液酸度的增加，阳离子物种Ru(Bpy)^2+的电极反应受到抑制，而阴离子物种Fe(CN)^3-_1的电极反应被促进。这些结果是从以下观点解释的：酸度的增加导致粘土表面质子化的增加，导致带正电的电极表面与反应物种之间的静电相互作用增强。在本研究中，首次证明了电极表面的带电状态对粘土修饰电极的电化学反应有重要影响。(2)苯胺被引入粘土的层间空间，然后进行电化学聚合。实验发现，电聚合反应非常缓慢，需要十几个小时才能完成反应，说明粘土层间的电化学反应速度很慢。(3)利用粘土层间掺杂的微晶二氧化钛作为光催化剂，对不同分子尺寸的正羧酸进行光催化降解。结果表明，小于粘土空隙的羧酸可以进入粘土层间进行反应，而较大的羧酸则不能进入活性较低的粘土层间。(4)用不同孔径的沸石分子筛制备了分子筛修饰电极，考察了Fe~(2+)~(2+)和Gt~(2+)在电极上的氧化还原行为。结果表明，当所用沸石的孔径大于水合Fe~(2+)离子和电解液阳离子的离子直径时，所含Fe~(2+)&Gt~(2+)离子在强酸性溶液中发生氧化还原反应。

(1) Redox dehaviors of Ru(bpy)^2+_(bpy=2,2 '-bipyridine) and Fe(CN)^3-_ ions at a clay-modified electrode were investigated as a function of acidity of solution, and it was foound that the electrode reaction of cationic species, Ru(bpy)^2+_, is suppressed but that of anionic species, Fe(CN)^3-_, is promoted with an increase in acidity. These results are explained from the viewpoints that the increase in acidity results in an increase in protonation of the clay surface, causing the enhancement of electrostatic interaction between the positively charged electrode surface and the reaction species. In the present study, it has firstly been shown that the charged state of electrode surface plays an important role in electrochemical reactions at clay-modified electrodes.(2) Aniline was incorporated in the interlayer space of clay and then polymerized electrochemically. The electropolymerization was found to proceed so slowly that it took more than ten hours to complete the reaction, giving the suggestion that the rate of electrolytic reactions in the interlayer space of clay is very slow.(3) Microcrystalline Tio_2 incorporated in the interlayer space of clay was used as a photocatalyst for photodecomposition of normal carboxylic acids with different molecular size. It was found that the carboxylic acids the size of which are smsller than the clearance space of the clay can be incorporated in the interlayer space of clay to undergo the reactions, while the larger carboxylic acids can not be incorporated in the interlayer space of clay exhibiting low reactivities.(4) Zeolite-modified electrodes were prepared by using zeolited with different pore size, and redox behaviors of Fe^<2+> ions at the electrodes were investigated. It was found that the redox reactions of the incorporated Fe^<2+> ions can thke place in strongly acidic solutions if the pore size of the zeolite used is larger than the ionic diameters of both hydrated Fe^<2+> ions and electrolyte cations used.