Nanotechnologies / Materials
Development for functional catalysts, Development for functional materials

Elucidation for reaction mechanism of CO2 immobilization in nanopores of C60
polymer via quantum chemical theory and computer simulation
Division of Chemical Engineering, Graduate School of Engineering Science
Associate Professor Yasutaka Kitagawa
Researchmap https://researchmap.jp/read0068726

Abstract

Nanotechnologies / Materials

A reaction mechanism that carbon dioxide and water molecules
become carbonate in the nanopores of fullerene C60 polymers wasexamined by the computer simulation based on quantum chemicaltheory (quantum chemical calculation). The quantum chemical calculation suggested the following mechanism: the carbon dioxide,
as the first step, is trapped and bridges two C60 polymers. By its
distorted structure and the charge polarization of the C60 polymers,
the trapped carbon dioxide is activated. The water molecule approaches to the activated carbon dioxide molecule, and then thereaction is considered to be easily occurred.

▍ Background & Results
Immobilization and reuse of the carbon dioxide are important
issues for achieving the SDGs. An effective method that makes
the stable carbon dioxide active and that leads it to the reaction,
however, has not been established yet. One of the effective approaches for the problem is considered to be the use of nanoporous materials such as zeolites and metal-organic frameworks thathave nano-sized spaces (nanopores) inside the compounds. The
nanopores are well-known to be used for storage, exchange, andseparation of molecules and ions. In addition, they also provide
specific reaction fields due to their narrow space, and are known
as catalysts.
It has been found that the one-dimensional C60 polymer which
involves nanopores is synthesized via the irradiation of the electron
beam to the thin layer of fullerene C60 by Professor Jun Onoe (Nagoya University) and coworkers. In addition, they also found thatthe carbon dioxide and water molecules become the carbonate
ion inside the nanopores of the one-dimensional C60 polymer. To
elucidate the reaction mechanism, the quantum chemical calculation was performed. The simulated result suggested the following
mechanism: the carbon dioxide, as the first step, is trapped andbridges two C60 polymers. By its distorted structure and the chargepolarization of the C60 polymers, the trapped carbon dioxide isactivated. The water molecule approaches to the activated carbon
dioxide molecule, and then the reaction is considered to be easily
occurred.

▍ Significance of the research and Future perspective
The computer simulation based of the quantum chemical theory
can elucidate the reaction mechanism that is hard to be clarified
by experiments. In addition, it is also a powerful tool for a design ofthe new functional materials. For the reason, the quantum chemical
calculation can accelerate the studies towards the achievement ofSDGs.

P a t e n t
Nakaya, Masato; Kitagawa, Yasutaka; Onoe, Jun et al. Immobilization of CO2 at Room Temperature Using the Specific Sub-NM Space of 1D Uneven-Structured C60 Polymer Film. Advanced Sustainable Systems. 2021; 5(1): 2000156. doi: 10.1002/adsu.202000156
https://resou.osaka-u.ac.jp/ja/research/2020/20201027_1
UR
L https://news.mynavi.jp/article/20201029-1444179/
https://research-er.jp/articles/view/93424
K e y w o r d quantum chemical theory, computer simulation, catalytic reaction mechanism, CO2 immobilization
Tr e a t i s e