2020 Fiscal Year Annual Research Report
Fundamental study on the synthesis of transition metal nanoparticles for the environmentally benign process using supercritical water
| Project/Area Number |
19K15348
|
|---|
| Research Institution | Tohoku University |
|---|
Principal Investigator |
成 基明 東北大学, 未来科学技術共同研究センター, 助教 (30747259)
|
|---|
| Project Period (FY) |
2019-04-01 – 2021-03-31
|
| Keywords | metal / nanoparticle / supercritical / flow reactor / EOS / hydrogen |
|---|
| Outline of Annual Research Achievements |
To develop an environmentally benign process for synthesis of metal nanoparticles, a new paradigm on the synthetic method is necessary. This study analyzes the factors contributing to the reaction through molecular simulation using the equation of state, and applies it to an actual reaction system to establish the basic technology for the synthesis of metal nanoparticles.
First, the validity of this simulation was verified by calculating the Henry's constant of hydrogen using Predictive Soave-Redlich-Kwong EOS and Volume-Translated Peng-Robinson EOS to which the group contribution was applied. Using the Dortmund Data Bank Software Package, the fugacity of water and hydrogen according to the temperature and pressure of subcritical-supercritical conditions was determined, and the reduction potential of hydrogen was estimated through the fugacity ratio of hydrogen and water.
In order to synthesis metal nanoparticles, conventional method was only possible with relatively high hydrogen concentration. Assuming that the oxide is reduced to metal, the formation of metal particles is affected by the particle size of the oxide. Since the particle size of oxide is proportional to the reaction time, the application of a non-equilibrium flow reactor that shortens the reaction time is essential. Therefore, since hydrogen, which is difficult to dissolve in water at atmospheric pressure, can be dissolved with high pressure water, the synthesis of metal nanoparticles was successful using a flow reactor and a relatively low hydrogen concentration under subcritical conditions.
|
