Photoelectrochemical reduction of Carbon dioxide by metal-complexes-membrane electrodes

金属配合物膜电极光电化学还原二氧化碳

基本信息

批准号：
06453114
负责人：
MIZUNO Takayuki
金额：
$ 4.8万
依托单位：
MIE UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06453114/
关键词：
Carbon dioxide Photocatalytic reduction Modified membrane electrode 光光学還元

项目摘要

Object : Phtochemical reduction of CO_2 is considered to be one of the most pro-mising approaches to photochemical conversion and storage of solar energy. An aqucous system of Ruthenium (II) -bipyridine complexes-methylviologen (MV^<2+>) -triethanolamine is one of homogeneous photosinsitized reductions of CO_2. In thissystem tricthanolamine is exhausted as sacrificial electron donor. With a view to search a cyclic system, we study on photoelectrochemical CO_2 reduction using coated membrane electrodes containing complexes and MV^<2+> without sacrificial clectron donor. Additionally photocatalytic reduction of CO_2 was studied using TiO_2 in suspension in liquid CO_2 and supercritical CO_2.Results :1.The electrode covered by the membranes containing Ru (bpy)_3^<2+> and MV^<2+> formed the largest photocurrent in the potential below -0.2 V.This indicates that Ru (bpy)_3^<2+> and MV^<2+> system in the membrane was most effective in generating photoc-urrent.2.In the Ru (bpy)_3^<2+> and MV^<2+> membrane system, exclusively II_2 was found as the reduction product. The electrode electrodeposited Pt or Ru reduced photoelectro-chemically CO_2 to produce malonic acid, acetic acid and formic acid as reduction products.3.We found that CO_2 was reduced by two stage reactions, that is, CO_2 fluid was photoc-atalytically reduced with TiO_2 in suspension and then protonated to formic acid by water addition.

目的：光化学还原CO_2被认为是最有前景的光化学转化和太阳能储存方法之一。钌(II)-联吡啶络合物-甲基紫精(MV 2+ )-三乙醇胺的水性体系是CO_2的均相光敏还原反应之一。在该系统中，三乙醇胺作为牺牲电子供体被耗尽。为了寻找循环系统，我们研究了使用含有配合物和MV^<2+>的涂层膜电极在不牺牲电子供体的情况下光电化学CO_2还原。另外还研究了悬浮液中的TiO_2和超临界CO_2对CO_2的光催化还原。结果：1.含有Ru(bpy)_3^<2+>和MV^<2+>膜覆盖的电极形成了最大的光电流在低于-0.2 V的电位下。这表明膜中的Ru (bpy)_3^<2+>和MV^<2+>系统最有效地产生photoc-urrent.2.在Ru(bpy)_3^<2+>和MV^<2+>膜系统中，仅发现II_2作为还原产物。电极电沉积Pt或Ru对CO_2进行光电化学还原,生成还原产物丙二酸、乙酸和甲酸。 3.我们发现CO_2的还原是通过两阶段反应进行的,即CO_2流体被TiO_2光催化还原悬浮液中，然后通过加水质子化为甲酸。