Preparation of metal ion-exchanged porous carbon nitride and elucidation of its characteristic properties

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K05157
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 27030:Catalyst and resource chemical process-related
• Research Institution: Tokyo University of Agriculture
• Principal Investigator: Onaka Makoto 東京農業大学, 生命科学部, 教授 (10144122)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: ナノ多孔質窒化炭素 / 多孔質固体塩基 / 水中固体塩基触媒作用 / ニトロアルドール反応 / 重水素化反応 / ニトロメタン / 高比表面積

Outline of Final Research Achievements

Layered carbon nitride, which is synthesized by calcining melamine, has a structure in which melem polymer chains are two-dimensionally linked by hydrogen bonding, but has a drawback of a very small specific surface area of 8.2 m2/g as a solid catalyst. Therefore, in order to develop a new type of highly porous carbon nitride material, the authors first treated the layered carbon nitride in concentrated sulfuric acid, followed by successive treatments with alkaline water and then alcohol. The new carbon nitride had a much larger specific surface area of 180 m2/g and was named as "nanoporous carbon nitride (nano-C3N4)".
This nano-C3N4 was not soluble in water, and its solid base catalytic ability was evaluated by 1) the nitroaldol reactions of nitromethane and aldehydes in pure H2O, and 2) the deuteration reaction of nitromethane in D2O.

Free Research Field

触媒有機化学

Academic Significance and Societal Importance of the Research Achievements

グラファイトは，現代人の生活の中で，多方面で不可欠な材料として利用されている有用な炭素素材である．一方，グラファイトを構成するベンゼン環の炭素原子がひとつおきに窒素原子に置き換わった構造の層状窒化炭素は，古くから知られた材料であるものの，その固体表面の露出度が少ないことから，なかなか活用されなかった．
本研究は，層状窒化炭素の表面露出度を数十倍高める手法を新奇に開発し，特にその素材が示す塩基性に注目し，水溶媒中で有機反応を加速する合成反応手法を新たに見出した．従来の有機合成反応の多くは有機媒体中で行われているのに対し，本触媒反応は環境にやさしい水媒体中で進む点に学術的・社会的意義がある．