Development of the highly difficult oxidation reaction with chlorine dioxide

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03010
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Osaka University
• Principal Investigator: Ohkubo Kei 大阪大学, 先導的学際研究機構, 教授 (00379140)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 二酸化塩素 / ラジカル / 酸化反応 / フルオラス溶媒 / ポリプロピレン / メタン / メタノール / 表面酸化

Outline of Final Research Achievements

Selective aerobic oxygenation of CH4 into liquid products without the concomitant formation of CO2 and CO has served as an elusive target reaction. The one-step transformation of CH4 into methanol (CH3OH) is carried out in nature using methane monooxygenases. However, under chemical conditions, the selective oxygenation of CH4 to CH3OH with molecular oxygen (O2) has been unknown because the oxidation of oxygenated products, CH3OH and formic acid (HCOOH) is much easier than that of CH4, leading to over-oxidation products such as CO and CO2. Chlorine dioxide radical (ClO2) was found to act as an efficient oxidizing agent in the aerobic C-H oxygenation of side-chain methyl groups of polypropylene under photoirradiation. Photochemical oxygenation of a polypropylene film occurred in a perfluorohexane solution or gas phase containing ClO2 gas under ambient conditions (298 K, 1 atm). The oxygenated side chain mainly consists of carboxylic acid and alcohol.

Free Research Field

光化学

Academic Significance and Societal Importance of the Research Achievements

これまで、大部分が燃焼による熱エネルギーとして消費されていたメタンガスが、これにより有用な化学物質へ変換できる方法が確立されたこととなる。本研究成果により、貴重な天然炭素資源の飛躍的な有効活用、および、エネルギー問題解決に繋がる技術となることが期待される。
また高分子の表面酸化については様々な材料への適用が可能であるために、化学繊維、医療器具、印刷などをはじめとする材料開発に大きく貢献できる技術であり、市場規模の大きさから、産業界に大きなインパクトを与える。