Research on Phetoreduction System for Supercritical Carbon Dioxide

点击翻译按钮获取中文摘要

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.