Research on Phetoreduction System for Supercritical Carbon Dioxide

超临界二氧化碳光还原系统的研究

• 批准号: 13650912
• 负责人: HIROSE Takuji
• 金额: $ 2.37万
• 依托单位: Saitama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650912/
• 关键词: Ruthenium Polypyridine Complex; Cobalt Polypyridine Complex; Visible Light; Photoreduction of CO_2; Cation Exchange Polymer; Supercritical CO_2; Two phase system; 超臨界二酸化炭素; 光還元; 光触媒; ルテニウム錯体; コバルト錯体; 一酸化炭素; ターンオーバー数; CO; H_2選択性

In order to develop the molecular system, which can efficiently and practically reduce CO_2 to CO as a chemical resource using visible light, new ruthenium (Ru) and cobalt (Co) polypyridine complex-system was investigated from the following three points.1. Development of efficient metal complex catalystsIn order to develop efficient photo-induced electron transfer metal complex systems, Ru and Co complex units were connected by conjugated carbon chain and the new bimolecular complex was investigated. As a result, fast electron transfer was observed but back electron transfer was also accelerated and no improvement of CO_2 reduction efficiency was attained.2. Improvement of metal complex life time and development of solid catalytic systemCationic Ru and Co complexes were fixed to ion exchange polymer and its photo-induced CO_2 reduction ability was investigated. As a result, the followings were found : 1) Solid catalytic system is easy to handle and recover the metal complexes ; 2) Although the efficiency was not improved for each photoirradiation, the life time of the complex system became long and the total amount of CO produced was increased.3. Development of supercritical CO_2 reaction systemIn order to establish a reaction system under high pressure or supercritical CO_2, a reaction vessel was developed and reaction conditions were investigated for photo-reduction. As a result, high CO_2 reduction rate was obtained under organic solvent-supercritical CO_2 two phase system. Now the reproducibility is examined in detail and investigation of a new system under supercritical CO_2 phase is also on going.

为了开发利用可见光有效、实用地将CO_2还原为CO作为化学资源的分子体系，对新型钌(Ru)和钴(Co)聚吡啶络合物体系进行了以下三点研究： 1．高效金属配合物催化剂的开发为了开发高效的光诱导电子转移金属配合物体系，Ru和Co配合物单元通过共轭碳链连接，并研究了新型双分子配合物。结果，观察到快速电子转移，但反电子转移也加速，并且没有实现CO_2还原效率的提高。2．金属配合物寿命的提高和固体催化体系的发展将阳离子Ru、Co配合物固定在离子交换聚合物上，并研究其光诱导CO_2还原能力。结果发现：1）固体催化体系易于处理和回收金属配合物； 2)虽然每次光照射效率并未提高，但复杂系统的寿命变长，CO产生总量增加。3．超临界CO_2反应体系的研制为了建立高压或超临界CO_2反应体系，研制了光还原反应容器并研究了反应条件。结果表明，在有机溶剂-超临界CO_2两相体系下获得了较高的CO_2还原率。目前，其重现性已得到详细检验，超临界CO_2相下的新系统的研究也在进行中。